Tuesday
May 21, 2013

# Homework Help: Science: Chemistry

chemistry
a 0.25 mol sample af neon gas at 18 C and 0.700 atm is heated to 40 C. the new gas pressure is 1.11 atm. what is the change in volumn of the neon gas?
Monday, February 4, 2013 at 4:38pm

Chemistry
you have 57.0 mL of a 2.00 M stock solution that must be diluted to 0.500 M. how much water should you add?
Monday, February 4, 2013 at 3:52pm

Chemistry
This is question 4a on section a.12 chemistry. What will you observe happening to the balloon as it sits in the warm car
Monday, February 4, 2013 at 3:18pm

Chemistry
you have 57.0 mL of a 2.00 M stock solution that must be diluted to 0.500 M. how much water should you add?
Monday, February 4, 2013 at 2:42pm

Chemistry
What is the activity coefficient of H^+ in a solution containing 0.073 M HCl and 0.0090 M Ca(ClO4)2? What is the pH of the solution? I believe I have to find the ionic strength of the solution first, but I don't know how to find it when 2 solutions are involved.
Monday, February 4, 2013 at 2:41pm

Chemistry
you have 57.0 mL of a 2.00 M stock solution that must be diluted to 0.500 M. how much water should you add?
Monday, February 4, 2013 at 2:35pm

Chemistry
you have 57.0 mL of a 2.00 M stock solution that must be diluted to 0.500 M. how much water should you add?
Monday, February 4, 2013 at 2:27pm

Chemistry
you have 57.0 mL of a 2.00 M stock solution that must be diluted to 0.500 M. how much water should you add?
Monday, February 4, 2013 at 2:24pm

Chemistry
Complete the charge balance equation for an aqueous solution of H2CO3 that ionizes to HCO3^- and CO3^2- ______ = ______ + _______ + _______ Given choices: [HCO3^-],[CO3^2-], [OH^-], 2[H^+], [H2CO3], 2[CO3^2-], 3[H^+], {H^+] I don't understand how to do charge balance :(
Monday, February 4, 2013 at 2:09pm

Chemistry
Find the Concentration of CrO4^2- in 0.0033M Ba(NO3)2 saturated with BaCrO4. Include activity coefficients in your solubility-product expression. Ksp of BaCrO4 = 1.17 x 10^-10 I have no idea what to do to solve this :(
Monday, February 4, 2013 at 2:03pm

chemistry
ionic and net ionic equation for sodium carbonate and potassium chloride
Monday, February 4, 2013 at 1:17pm

chemistry
net ionic equation for KI+Na2So2O3+KCl
Monday, February 4, 2013 at 12:44pm

college chemistry
How many grams would you weigh out to get 3.1 X 10-3 Moles of MgCl2?
Monday, February 4, 2013 at 12:26pm

chemistry
A fixed mass of gas has a volume of 440cm3 at 13degree cetigrate and 836mmhg.calculate its volume at s.t.p.
Monday, February 4, 2013 at 3:48am

chemistry
For the reaction below, KP = 1.6 × 106 at 400.0 °C. HCHO2( g ) <--> CO( g ) + H2O( g ) A mixture of CO( g ) and H2O(l ) was prepared in a 2.00 L reaction vessel at 25 °C in which the pressure of CO was 0.177 atm. The mixture also contained 0.391 g of H2O. ...
Monday, February 4, 2013 at 12:47am

chemistry
The nuclear reaction Sn ¨ Sb + ? is an example of
Monday, February 4, 2013 at 12:16am

Chemistry
Fe 3+ + scn- + Na2PHO4 produces what exactly?
Monday, February 4, 2013 at 12:08am

chemistry
An object has a KE= 18000 and a massof 98kg what is the speed of the object
Sunday, February 3, 2013 at 11:54pm

chemistry
how many grams of lithium bromide are in 0.79 mol.of lithium bromide?
Sunday, February 3, 2013 at 8:14pm

Chemistry
Hi, Just have follow up questions to the previous questions asked dating Feb. 02, 2013 1. So the overall idea is that dissociation decreases molar mass and association does the opposite when a solute dissolves in a solvent. (How do you identify if either reaction occurs? Just ...
Sunday, February 3, 2013 at 6:29pm

chemistry
can u tell me whats the most imprtant subject i need to know for molecular composition of gases ? and for physical characteristics of gases?
Sunday, February 3, 2013 at 6:16pm

chemistry
80ml of hcl is added to 2.5gm of pure cac03 when the reaction is over, then 0.5gm cac03 is left. Find the normality of the acid The answer 0.5N Who helps step by step
Sunday, February 3, 2013 at 6:10pm

Chemistry
How many moles of H atoms are there in 21.66 g of Mg(OH)2? What is the mass of F (in g) in 8.03 x 1023 BF3 molecules
Sunday, February 3, 2013 at 5:59pm

Chemistry
If 25 grams of copper(II) sulfate pentahydrate were heated until all water was removed, how much residue would remain?- Could someone help me understand this question? I don't understand it at all. Thanks
Sunday, February 3, 2013 at 5:28pm

CHEMISTRY URGENT!
a sample of oxygen that occupies 1.00 x 10^6mL at 575mmHg is subjected to a pressure of 1025atm. what will the final volume of the sample be if the temperature is held constant? how do uu set up the equation
Sunday, February 3, 2013 at 5:12pm

Chemistry
Is there a chemical formula for animal fats? - Would the lipids chemical formula be the same as animal fats? Thanks
Sunday, February 3, 2013 at 5:03pm

Chemistry
How many moles of OCl2 contain 38.42 g of Cl? Answer
Sunday, February 3, 2013 at 4:48pm

Chemistry
I did a lab that involve cooking meat and finding the mass of lipids, meat tissue and water. For a chicken sample the original mass was 20 gram. After cooking there was 15.5g of meat, and 1.5 g of oil, and 1 g of water. I am missing 2 g of the original mass. Anyone have any ...
Sunday, February 3, 2013 at 4:43pm

Chemistry
For the reaction of hydrazine (N2H4) in water, Kb is 3.0 10-6. H2NNH2(aq) + H2O(l)--> H2NNH3+(aq) + OH-(aq) Calculate the concentrations of all species and the pH of a 1.6 M solution of hydrazine in water. [OH-] = [H2NNH3+] = [H2NNH2] = [H+] = pH =
Sunday, February 3, 2013 at 4:26pm

chemistry
For the reaction below, Kp = 1.16 at 800.°C. CaCO3(s) CaO(s) + CO2(g) If a 21.7-g sample of CaCO3 is put into a 10.6 L container and heated to 800°C, what percentage by mass of the CaCO3 will react to reach equilibrium?
Sunday, February 3, 2013 at 3:18pm

chemistry
For the reaction below, Kp = 1.16 at 800.°C. CaCO3(s) CaO(s) + CO2(g) If a 21.7-g sample of CaCO3 is put into a 10.6 L container and heated to 800°C, what percentage by mass of the CaCO3 will react to reach equilibrium?
Sunday, February 3, 2013 at 3:18pm

chemistry
How much heat (in cal) is necessary to heat 27.0 mL of octane (s= 0.526 cal/g ®C ; d = o.703 g/mL ) from 50.6 ®C to 67.2 ®C? I understand the Delta T is = 16.6®C But I don’t know what d stands for (density) or how to apply to the formula.
Sunday, February 3, 2013 at 2:06pm

CHEMISTRY URGENT!
assume that 13.5g of AL react with HCl according to the following equation, at STP: Al(s) + HCl(aq) ---> AlCl3 + H2(g) Remember to balance the equation first. a. how many moles of Al react? b. how mang moles of H2 are produced? c. how mang liters of H2 at STP are produced? ...
Sunday, February 3, 2013 at 2:02pm

chemistry
i have some question but i can not post it ,what should i do .help
Sunday, February 3, 2013 at 12:06pm

Chemistry
The air we inhale contains O2 we exhale CO2 and H2O does this suggest that our bodily processes invove oxidation? Why?
Sunday, February 3, 2013 at 11:49am

analytical chemistry
In an experiment for determining water hardness, 75.00 ml of a water sample required 13.03 ml of an EDTA solution that is 0.009242 M. What is the ppm CaCO3 in this sample? Could someone please tell me if this is correct? Total hardness, ppm CaCO3 = mg CaCO3 / L = 13.03 ml x 1....
Sunday, February 3, 2013 at 11:45am

chemistry
1.00 g zinc and 0.80 g sulfur are allowed to react all the zinc is used up 1.50 g of zinc sulfide is formed and some unreacted sulfur remains what is the mass of unreacted sulfur
Sunday, February 3, 2013 at 11:29am

Chemistry
What is a Balanced equation for sulfur (IV) oxide (g) and magnesium oxide (cr)?
Sunday, February 3, 2013 at 11:27am

analytical chemistry
An EDTA solution is standardized against a solution of primary standard CaCO3 (0.5622 g dissolve in 1000 ml of solution) and titrating aliquots of it with the EDTA. If a 25.00 ml aliquot required 21.88 ml of the EDTA, what is the concentration of the EDTA?
Sunday, February 3, 2013 at 8:26am

Chemistry
How to make 10% nitric acid? wouldnt it be 10 mL nitric acid + 100 mL of solvent, making it 10%? What molarity is used it to make 10% nitric acid?
Sunday, February 3, 2013 at 6:17am

organic chemistry
how do I to draw cyclopropane of bond rotation?
Sunday, February 3, 2013 at 12:30am

chemistry
Write the formula of the conjugate acid of base HCO3-,HPO2-,PO43-,SO32-
Saturday, February 2, 2013 at 11:53pm

chemistry
Classify each of the follow species as bronsted lowry acid or base NH3,NCN
Saturday, February 2, 2013 at 11:41pm

Chemistry
Freezing point of pure water = -2, Freezing point of Unknown solution = -1 Mass of unknown in 50g of water = 1.9964g. Calculate the delta T for the solution of the unknown solid and determine the molecular weight of the unknown solid.
Saturday, February 2, 2013 at 11:39pm

chemistry
how many grams of magnesium are required to react with 2.0 moles of hydrochloric acid?
Saturday, February 2, 2013 at 10:28pm

college general chemistry
Calculate the volume of a rectangular solid with a thickness of 0.750 cm and an area of 8.25 cm2
Saturday, February 2, 2013 at 10:22pm

Chemistry
You have a 100mL cylinder containing 40mL of water. A cube measures 2cm on each side is lowered into the cylinder. What is the new volume reading of the cylinder?
Saturday, February 2, 2013 at 10:08pm

Chemistry
Can someone pls help me!! You decide to establish a new temperature scale on which the melting point of ammonia (-77.75 C ) is 0 A, and the boiling point of ammonia (-33.35 C ) is 200 A. What would be the boiling point of water in A ? What would be the temperature of absolute ...
Saturday, February 2, 2013 at 9:37pm

Chemistry
You decide to establish a new temperature scale on which the melting point of ammonia (-77.75 C ) is 0 A, and the boiling point of ammonia (-33.35 C ) is 200 A. What would be the boiling point of water in A ? What would be the temperature of absolute zero in A ?
Saturday, February 2, 2013 at 5:34pm

chemistry help !!!!!!!!!!!!!!!!
complete the following paragraph relating to the enzyme,b -galactosidase .this enzyme hydrolyses the disaccharide lactose to constituent monosaccharides ,galactose and glucose ,drag and drop the approprite words into the correct space. the enzyme ,B-galactosidase is added to a...
Saturday, February 2, 2013 at 5:11pm

chemistry help !!!!!!!!!!!!!!!!
complete the following paragraph relating to the enzyme,b -galactosidase .this enzyme hydrolyses the disaccharide lactose to constituent monosaccharides ,galactose and glucose ,drag and drop the approprite words into the correct space. the enzyme ,B-galactosidase is added to a...
Saturday, February 2, 2013 at 5:10pm

Chemistry
The density of aluminum is . A square piece of aluminum foil, 20.02 on a side is found to weigh 2.573 .What is the thickness of the foil, in millimeters?
Saturday, February 2, 2013 at 4:27pm

Chemistry
A vinegar sample is found to have a density of 1.006 and to contain 4.7 acetic acid by mass.How many grams of acetic acid are present in 3.00 of this vinegar?
Saturday, February 2, 2013 at 4:21pm

Chemistry
54.0 mL of a 1.50 M solution is diluted to a total volume of 258 mL. A 129-mL portion of that solution is diluted by adding 165 mL of water. What is the final concentration?
Saturday, February 2, 2013 at 3:01pm

Chemistry
A gas occupies a volume of 502 cm3 at 20.0 C. What will be its volume at 106 C? I understand that it follows Charles' Law where the correct equation is V1/T1=V2/T2. My teacher expects all units of volume to be converted to Liters and all temperature to Kelvins. Using ...
Saturday, February 2, 2013 at 12:28pm

Chemistry Problem
Consider an ionic compound, MX, composed of generic metal M and generic halogen X. The enthalpy of formation of MX is ÄHf° = –457 kJ/mol. The enthalpy of sublimation of M is ÄHsub = 121 kJ/mol. The ionization energy of M is IE = 433 kJ/mol. The electron ...
Saturday, February 2, 2013 at 1:25am

Chemistry
In the situation that a solute dissolves in a solvent, the solute molecules often dissociate and associate. Studying for exam, not sure how to explain HOW dissociation and association affects the molar mass of the solute in this system. (What is dissociation and association?)
Saturday, February 2, 2013 at 1:01am

Chemistry
In the case of a small amount of your unknown failed to dissolve in the t-butanol, would it effect the molar mass? = Does molarity increase as molar mass increases?
Saturday, February 2, 2013 at 12:40am

Chemistry
You have 1.0 mol of HCL and you want to dilute it to .1 mol. How many mL out of 50 should it take up?
Saturday, February 2, 2013 at 12:35am

Chemistry
At 1 atm, how much energy is required to heat 67.0 g of H2O(s) at –14.0 °C to H2O(g) at 115.0 °C? Please explain, I'm not very good at Chemistry and this problem is giving me a headache. Thank you!
Saturday, February 2, 2013 at 12:00am

To gina
I have deleted your post. PLEASE do not put personal information (names, phone numbers, and that kind of thing) on this site. The Internet is not a safe place for that information. I am sorry you arre having trouble with chemistry; however, you must understand that we don'...
Friday, February 1, 2013 at 9:22pm

chemistry 1B
A sample of gas occupies a volume of 61.2 mL. As it expands, it does 133.9 J of work on its surroundings at a constant pressure of 783 torr. What is the final volume of the gas.
Friday, February 1, 2013 at 8:53pm

Chemistry
At 400°C the reaction H2+I2<->2HI has an equilibrium constant Kp value of 55.5. A mixture of 1 mole of H2 and 1 mole of I2 is placed in a flask and heated to 400°C. Calculate the mole fraction of HI in the mixture of gases when equilibrium reached.
Friday, February 1, 2013 at 6:00pm

Chemistry
Explain the following phenomena in terms of intermolecular forces. Determine the major type of forces between the molecules. a) You can't clean grease off you hand with water only b) Pancake syrup is more dense than olive oil. Please provide the structure of both in your ...
Friday, February 1, 2013 at 5:31pm

ENGLISH, HELP?
In the following sentence, which words should be in quotation marks? Did you read the chapter Chemical Reactions in our science textbook, Understanding Chemistry? A. chapter Chemical Reactions B. Chemical Reactions C. Understanding Chemistry I think the answer is B, as it is a...
Friday, February 1, 2013 at 5:09pm

Chemistry 3A
You want to make the following buffer: 5% glucose, 100 mM tris and 10 mM EDTA in a final voume of 300ml. Your stock solutions are 20% glucose, 1M tris and 0.5M EDTA. The diluent is distilled water. Determine how much of each you will add to make the desired buffer. I know this...
Friday, February 1, 2013 at 4:58pm

Chemistry
I had a 1.094g of mystery Alum. "AB(SO4)c. dH2O" (I assume that that the Alum is KAl(SO4)2-12H2O but we don't know A B c or d, we do know that mass percent of water is 51.9) After processing the alum (Ba(NO3)2 and HNO3 through a gooch crucible) we end up with 1....
Friday, February 1, 2013 at 3:07pm

chemistry
How do you make 300 ml of a 2M solution from a 50 M stock solution?
Friday, February 1, 2013 at 12:17pm

chemistry
how long would it take for 1.50 mol of water at 100C to be converted completely into steam if heat were added at a constant rate of 18.0J/s?
Friday, February 1, 2013 at 11:15am

Chemistry
What weight of solute (M,wt =60) is required to be dissolved in 180gm of water to reduce vapour pressure to 4/5th of pure water?
Friday, February 1, 2013 at 11:11am

Chemistry
Find molality of a solution containing non - volatile solute if its vapour pressure is 2% below the vapour pressure of pure water
Friday, February 1, 2013 at 11:04am

Chemistry
30g of the palm shell were mixed with 15ml H3PO4 and 100ml of distilled water in a 250ml conical flask.The concentration of H3PO4 solution was 2.2M, from question,how to prepare those from ortho phosporic acid (98g/mol).Do help me, is it need to make a stock solution first and...
Friday, February 1, 2013 at 10:26am

chemistry
Calculate the amount of heat required to heat a 3.6{\rm kg} gold bar from 20^\circ {\rm C} to 70^\circ {\rm C}. Specific heat capacity of gold is 0.128 \rm J/g ^\circ C
Friday, February 1, 2013 at 9:58am

chemistry
why NH4+ ion is not strong ligand
Friday, February 1, 2013 at 5:03am

chemistry
The density of water at 30.0 °C is 0.9956 g/mL. If the specific gravity of acetic acid is 0.1040 at 30.0 °C, what is the density of acetic acid at 30.0 °C?
Friday, February 1, 2013 at 1:55am

Chemistry
How do I calculate the joules to heat 17 g of water from 22 degrees C to 78 degrees C?
Thursday, January 31, 2013 at 9:46pm

Chemistry
What volume does 0.25 moles of oxygen gas occupy ar STP?
Thursday, January 31, 2013 at 9:27pm

Chemistry
What is the molar volume of the gas ammonia (NH³) at STP?
Thursday, January 31, 2013 at 9:24pm

Chemistry
I am trying to study for my chem test but I don't get how to answe this question A researcher explores the ideal gas equation. He measures the pressure of a system at different temperatures ( keeping the volume and moles of the gas constant) and creates a plot of P versus ...
Thursday, January 31, 2013 at 9:22pm

chemistry
how many valence electrons does copper (Cu), nickel (Ni), and cobalt (Co) have?
Thursday, January 31, 2013 at 9:19pm

Chemistry
If you have 1 mole of baking soda (NaHCO³), then about how many atoms of oxygen do you have?
Thursday, January 31, 2013 at 9:14pm

Chemistry
For the theoretically perfect reaction 2H² +O²---2H²O if you react 300 molecules pf hydrogen and 200 molecules of oxygen, how many oxygen molecules will you have that do not engage in the reaction? Answer 50, 100, 150, or 200?
Thursday, January 31, 2013 at 8:58pm

chemistry
A gas has a volume of 590mL at a temperature of -55.0C What volume will the gas occupy at 30.0C Can someone help me?
Thursday, January 31, 2013 at 8:45pm

Organic Chemistry
Why is the melting point of a known compound (ex. acetanilide) determined before the melting point of the unknown compound? I think it is to determine if the unknown is a pure substance but I am not sure..I just need to be pointed in the right direction.
Thursday, January 31, 2013 at 6:30pm

science:Chemistry
Find the pH of a solution obtained by mixing 100cm3 of 01MHCl solution with 100cm3 of 0.2M NaOH
Thursday, January 31, 2013 at 5:26pm

Chemistry
Which ligand binds the tightest? Ligand A, with a Kd of 10^-9M Ligand B, with a Kd of 10^-3M Ligand C, with a percent occupancy of 30% at one micromolar Ligand D, with a percent occupancy of 80% at 10 nm
Thursday, January 31, 2013 at 3:45pm

Chemistry
At what temperature will the rate constant for the reaction have the value 6.5×10−3 M/s? (Assume k = 5.4 * 10^-4 M/s-1 at 599K and k = 2.8 * 10^-2 M/s at 683K .)
Thursday, January 31, 2013 at 2:57pm

chemistry
If 145 J of heat energy is applied to 34.47 g of an unknown metal, the temperature increases from 61.0 degree C to 78.5 degrees C. What is the specific heat capacity of the unknown metal?
Thursday, January 31, 2013 at 2:49pm

Chemistry
MIke and Shayne reacted sodium chloride with silver nitrate as indicated in the reaction below: AgNO3(aq) + NaCl(aq) → AgCl (s) + NaNO3 (aq) The actual yield of their silver chloride was 0.365 g. According to their calculations, they should have theoretically obtained 0...
Thursday, January 31, 2013 at 2:43pm

Chemistry
What is the largest amount of H2O in grams that can be formed when 6.10 g of H2 reacts with 6.10 g of O2, based on 2 H2 + O2 = 2 H2O
Thursday, January 31, 2013 at 2:41pm

Chemistry
Calculate the half-life (in s) of a first-order reaction if the concentration of the reactant is 0.0655 M 18.4 s after the reaction starts and is 0.0173 M 41.2 s after the reaction starts. I got 25.6 Suppose the half-life is 23.7 s for a first order reaction and the reactant ...
Thursday, January 31, 2013 at 1:59pm

Chemistry
I am trying to determine which protein (in a given list) will stick most tightly to a cation exchange column at pH 7. I am unsure how to go about solving this.. We are given molecular weight, isoelectic point, and number of subunits for each protein. Where should I begin?
Thursday, January 31, 2013 at 1:47pm

Chemistry
I am trying to determine which protein (in a given list) will stick most tightly to a cation exchange column at pH 7. I am unsure how to go about solving this.. We are given molecular weight, isoelectic point, and number of subunits for each protein. Where should I begin?
Thursday, January 31, 2013 at 1:47pm

General Chemistry
How many milliliters of 0.5M NaOH must be added to 200 mL of 0.1M NaH2PO4 to make a buffer solution with a pH of 6.9?
Thursday, January 31, 2013 at 11:05am

chemistry
sodium metal dissolves im liquid mercury to form of NA(s) and Hg(l) are 0.97 g/ml and 13.6 g/ml respectively. a sodium amalgoum is made by dissolving 10 ml Na (s) in 20.0 ml Hg (l). The final volume of solution is 21.0 ml. Calculate the molarity of Na in the solution.
Thursday, January 31, 2013 at 9:43am

Chemistry
calculate the enthalpy change for: (enthalpy of formation of aqueous sodium hydroxide is -469.60 kJ/mol. enthalpy of formation of liquid water is -285.8 kJ/mol) 2Na + 2H2O = 2 NaOH + H2
Thursday, January 31, 2013 at 9:09am

Chemistry
If Chelcy and Allyson reacted 2.55 grams of Mg with excess hydrochloric acid (HCl), how many grams of MgCl2 will they theoretically produce? Mg(s) + HCl (aq) → H2 (g) + MgCl2 (aq) ?g MgCl2
Thursday, January 31, 2013 at 8:57am

Chemistry
How many moles of P4O10 can be produced with 8.084e-001 moles of the limiting reagent?
Thursday, January 31, 2013 at 8:56am

Chemistry
How many grams of lithium nitrate are needed to produce 100 grams of lithium sulfate when lithium nitrate reacts with lead (IV) sulfate to form lithium nitrate and lead (IV) nitrate
Thursday, January 31, 2013 at 8:14am

Chemistry
A researcher studying the nutritional value of a new candy places a 4.30-gram sample of the candy inside a bomb calorimeter and combusts it in excess oxygen. The observed temperature increase is 2.77 °C. If the heat capacity of the calorimeter is 28.90 kJ·K–1, ...
Thursday, January 31, 2013 at 2:41am

chemistry
An organic compund has a molar mass of 178.3g/mol and contains 7.29% hydrogen atoms by mass. How many hydrogen atoms are in each molecule of this compound
Thursday, January 31, 2013 at 2:12am

chemistry
A 1.800 g sample of octane, C8H18, was burned in a bomb calorimeter whose total heat capacity is 11.66 kJ/°C. The temperature of the calorimeter plus contents increased from 21.12°C to 29.85°C. What is the heat of combustion per gram of octane? What is the heat of ...
Thursday, January 31, 2013 at 2:01am

Chemistry
A sample of gas occupies a volume of 63.1 mL. As it expands, it does 130.4 J of work on its surroundings at a constant pressure of 783 torr. What is the final volume of the gas? I know that P= 1.03 ATM when converted. I think I'm supposed to use the equation w= -PdeltaV ...
Thursday, January 31, 2013 at 1:47am

Chemistry
How many molecules are there in 24 grams of FeF3 ? Can somebody please show me how i can get to the answer ? Thank you
Wednesday, January 30, 2013 at 11:21pm

chemistry
what is the volume of a cube that has the following measurements (length 20.0 cm, width 152 mm, height 0.458 m)
Wednesday, January 30, 2013 at 10:51pm

Chemistry
An object made of aluminum has a mass of 8.37g. When it was placed in a graduated cylinder containing 20.0ml of water, the water level rose to 23.1ml. Calculate the specific gravity of the object?
Wednesday, January 30, 2013 at 9:44pm

Chemistry
If the freezing point of pure toluene is -95.15 oC and its freezing point depression constant is -8.38 oC/molal, what is the freezing point of a solution made by dissolving 39.338g of anthracene (C14H10) in 150.0mL of toluene? (Density of toluene = 0.8669g/mL)
Wednesday, January 30, 2013 at 9:34pm

Chemistry
How many moles of carbon dioxide would be produced if 25 g of copper carbonate were completely decomposed by heating?
Wednesday, January 30, 2013 at 9:02pm

ap chemistry
The system CO2(g) + H2(g) *) H2O(g) + CO(g) is at equilibrium at some temperature. At equilibrium a 4.00 L vessel contains 1.00 mole CO2, 1.00 mole H2, 2.40 moles H2O, and 2.40 moles CO. How many moles of CO2 must be added to the system to bring the equilibrium CO ...
Wednesday, January 30, 2013 at 6:32pm

Chemistry
How much heat energy, in kilojoules, is required to convert 36.0g of ice at 18.0C to water at 25.0C
Wednesday, January 30, 2013 at 6:20pm

chemistry
the helium in a 1.5L flask at 25degrees celcius exerts a pressure of 56.65kPa. How many moles of helium are in the flask?
Wednesday, January 30, 2013 at 6:16pm

H. CHemistry
if the atmosphere can support a column of mercury 760 mm high at sea level, what height of a hypothetical liquid whose density is 1.40 times the density of mercury could supported?
Wednesday, January 30, 2013 at 6:13pm

Chemistry
Calories of heat absorbed by water = (Mass undergoing change)(Change in temp.)How much heat is needed to warm 125 g. of water from 25 degrees Celsius to 100 degrees Celsius. Thank you very much!
Wednesday, January 30, 2013 at 6:08pm

general chemistry
A reaction involves fictional reagents A & B is begun with the inital concentration of 0.05M A and 0.01M B. The reaction reaches completion in 16 seconds. What is the initial rate of the reaction in respect to A? and what is the order in respect to B
Wednesday, January 30, 2013 at 6:05pm

Chemistry
Sample has 150 grams, 20 mL, and a density of 7.5 g/mL. If I double my sample size what would those values turn into?
Wednesday, January 30, 2013 at 5:55pm

chemistry
disappearance of NO in ...- Help!!!? The following data were collected for the rate of disappearance of NO in the reaction 2 NO(g) + O2(g) ¨ 2 NO2(g). Run: [NO](M) [O2](M) Initail Rate (M/s) 1 .0126 .0125 1.41 X 10^-2 2 .0252 .0125 5.64 X 10^-2 3 .0252 .0250 1.13 X ...
Wednesday, January 30, 2013 at 5:55pm

chemistry final step
If you have 24.98 grams of P and 74.99 grams of O2, how many moles of each compound do you have present? so I got .805 of P (limiting) and 2.343 O2 (excess) how do i do this step ? If you have 24.98 grams of P and 74.99 grams of O2, how many moles of each compound do you have ...
Wednesday, January 30, 2013 at 4:45pm

Organic Chemistry 2
Hello, I have two questions Why is simple distillation useful in isolating pure isopentyl acetate? How do you predict the major peaks that would be observed in a isopentyl alcohol and isopentyl acetate infrared spectra?
Wednesday, January 30, 2013 at 2:52pm

Chemistry
You carry out an exothermic reaction inside a Styrofoam cup calorimeter, using a temperature probe to monitor the temperature throughout the reaction. You find that the temperature increases 7.40 °C during the reaction. The specific heat of the reaction solution is known ...
Wednesday, January 30, 2013 at 1:39pm

chemistry
4 P + 5 O2 ==> P4O10 If you have 24.98 grams of P and 74.99 grams of O2, how many moles of each compound do you have present?
Wednesday, January 30, 2013 at 1:04pm

Chemistry
calculate the 0.4M molarity of ammonia From data given, how to prepare 200ml of 0.4M ammonia solution 25%. From previous study, i found that the calculation is M1V1=M2V2 From formula, Initial concentration (M1)is 910000mg/L, vOlume of beaker (V2)=200ml, but the required ...
Wednesday, January 30, 2013 at 10:18am

chemistry help plz
Using the melting temperature given as guidance, state the type of bonding involved between the elements in aluminium sulfide (Al2S3). Explain how this bonding takes place with respect to the valence electrons.
Wednesday, January 30, 2013 at 6:08am

chemistry
Consider Ba (NO₃)₂ + K₂SO₄ → BaSO₄ + 2KNO₃ (0.10 M) (0.10 M) (10.0 mL) (20.0 mL) Will the K₂SO₄ be sufficient to precipitate all the Ba⁺² ions in the Ba (NO₃)₂? Use Stoichiometry to answer this ...
Wednesday, January 30, 2013 at 5:26am

Chemistry
Assume the solubility of benzoic acid in ice-cold water is 1.70 g/L and the solubility of benzoic acid in hot water is 68.0 g/L. Calculate the minimum volume of water (in mL) needed to recrystallize 0.350 g of benzoic acid.
Wednesday, January 30, 2013 at 5:24am

Chemistry
Have have 3 general question regrading Analysis of the hardness of water: 1. What is meant by non-zero blank correction in calculating EDTA?(Whats the effects?) 2. EDTA in an experiment was not dry would it effect the EDTA solution? 3. EDTA in an experiment was not dry would ...
Wednesday, January 30, 2013 at 3:51am

chemistry
determine the quantity of heat needed to convert 17.0g of solid mercury at -50.0C to mercury vapor at 25C . Specific heats: , 24.3C , , 28.0C . Melting point of hg, -38.87C . Heat of fusion, 2.33 .
Wednesday, January 30, 2013 at 1:34am

Chemistry
Theres an airplane with a mass of 5.4g, 305. mm long, moving at 1.8m/s. Is it classic or quantum?
Wednesday, January 30, 2013 at 12:38am

Chemistry
Draw the possible products resulting from the addition of 1 equivalent of HCL to 1-phenyl-1,3-butadiene. Which would you expect to predominate and why?
Wednesday, January 30, 2013 at 12:36am

Chemistry
Consider the reaction 5Br(aq) + BrO3(aq) + 6H^+(aq)-> 3Br2(aq) + 3 H2O(l? The average rate of consumption of Br- is 1.16×10-4 over the first two minutes. What is the average rate of formation of Br2 during the same time interval?
Wednesday, January 30, 2013 at 12:17am

Chemistry
The problem ask what is the mass of iron(iii) chloride contains 2.35 x 10^23 chloride ions. I understand the molar mass is 162.20 g/mol. - 2.35 x 10^23 chloride ions would be around 0.39 moles. - The work that my teacher gave me is 0.39 moles * (1 mol FeCl3 / 3 mol chloride ...
Tuesday, January 29, 2013 at 11:19pm

Chemistry
If 225.O grams of NO react with excess NH3,how many grams of H2O are produced
Tuesday, January 29, 2013 at 10:50pm

Chemistry
How many grams of N2 are produced when 15.0 moles of NH3 react with excess NO
Tuesday, January 29, 2013 at 10:48pm

Chemistry
how many moles of NO are needed to react with 15.0 moles of NH3
Tuesday, January 29, 2013 at 10:45pm

Chemistry
How many grams of HgBr2 can be produced if 10.0 grams of Hg reacts with 10 grams Br2
Tuesday, January 29, 2013 at 10:42pm

Chemistry
how many moles of sodium oxide are produced when 3.9 moles of of sodium combine with excess oxygen
Tuesday, January 29, 2013 at 10:38pm

Chemistry
How many moles of ion are in the following? A. 0.0200 g AgNO3 - Could someone give me the step to solve such problems? Thanks
Tuesday, January 29, 2013 at 9:56pm

College Chemistry
what might be the reason that this is happening: During a simple distillation i have 14ml or 50/50 hexane;toluene mixture in a 25mL round-bottom flask. However, by the time i collected 8ml of distillate there were no liquid left in the flask.
Tuesday, January 29, 2013 at 9:56pm

Chemistry
At –11.0 °C (a common temperature for household freezers), what is the maximum mass of aspartame (C14H18N2O5) you can add to 1.50 kg of pure water and still have the solution freeze? Assume that aspartame is a molecular solid and does not ionize when it dissolves in ...
Tuesday, January 29, 2013 at 9:40pm

Chemistry
Classify these mixtures as colloids, suspensions, or true solutions. fog, milk of magnesia, mayonnaise, blood, table salt in water, dust-free air I got fog, milk of magnesia, mayonnaise for colloids. Blood for suspensions. Table salt in water and dust-free air for true ...
Tuesday, January 29, 2013 at 9:35pm

Chemistry
Biphenyl, C12H10, is a nonvolatile, nonionizing solute that is soluble in benzene, C6H6. At 25 °C, the vapor pressure of pure benzene is 100.84 torr. What is the vapor pressure of a solution made from dissolving 19.6 g of biphenyl in 25.1 g of benzene?
Tuesday, January 29, 2013 at 9:23pm

Chemistry
The boiling point of an aqueous solution is 102.48 °C. What is the freezing point? I know that formula for freezing point is delta Tf = Kf*m but what do I plug in for each?
Tuesday, January 29, 2013 at 9:22pm

Chemistry
When 4.65 g of a nonelectrolyte solute is dissolved in 475 mL of water at 27 °C, the resulting solution exerts an osmotic pressure of 931 torr. What is the molar concentration of the solution? How many moles of solute are in the solution? What is the molar mass of the ...
Tuesday, January 29, 2013 at 9:13pm

Chemistry
A sample of nitrogen gas is collected over water at a temperature of 23°C. What is the pressure of the nitrogen gas if the atmospheric pressure is 791 mm Hg? Answer in units of mm Hg
Tuesday, January 29, 2013 at 8:35pm

chemistry
Solutions of sulfuric acid and lead acetate react to form solid lead sulfate and a solution of acetic acid.5.80 of sulfuric acid and 5.80 of lead acetate are mixed. Calculate the number of grams of acetic acid present in the mixture after the reaction is complete.
Tuesday, January 29, 2013 at 8:04pm

chemistry
Calculate the number of grams of acetic acid present in the mixture after the reaction is complete.
Tuesday, January 29, 2013 at 8:03pm

chemistry.....help plz
what is the density of methane gas at 20 degree and 115kpa?
Tuesday, January 29, 2013 at 7:46pm

The electron-domain geometry and molecular geometry of iodine trichloride are __________ and __________, respectively.
Tuesday, January 29, 2013 at 7:12pm

Chemistry
What would be the effect of each of the following on the calculated molecular weight of the solute? a) some cyclohexane evaporated while the freezing point of pure cyclohexane was being measured. ( i think it would be higher) b)Some cyclohexane evaporated after the solute was ...
Tuesday, January 29, 2013 at 6:57pm

Chemistry
What is the limiting reagent when 10.8 g water reacts with 4.7 g Na to produce NaOH and H2?
Tuesday, January 29, 2013 at 6:10pm

chemistry
peice of sodium metal reacts with water. 246ml volume of hydrogen gas was collected over water at 25 celsius and at an atmospheric pressuric pf 101.3 kpa. what was the pressure of dry hydrogen? what is the mass of sodium used up by the reaction?
Tuesday, January 29, 2013 at 6:07pm

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