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December 22, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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Chemistry
a 175.0 ml solution is made up of 20.0g of titanium(iii) chloride and H2O. What is it's molarity? I am just trying to check my work. M= 0.1296/0.175 =0.740
Saturday, October 11, 2014 at 9:41pm

Chemistry
Assume that you start with 2 mole(s) of magnesium metal, determine: The number of grams of MgO(s) that would be produced in the following reaction (enter your answer with 4 significant figures): Mg(s) + 1/2O2(g) → MgO(s)
Saturday, October 11, 2014 at 9:34pm

Chemistry
Write the balanced molecular equation for the reaction between lithium phosphate and calcium nitrate.
Saturday, October 11, 2014 at 9:26pm

chemistry
An alternative approach to bomb calorimetry is toestablish the heat capacity of the calorimeter, exclusive of the water it contains. The heat absorbed by the water and by the rest of the calorimeter must be calculated separately and then added together. A 1.148g sample of ...
Saturday, October 11, 2014 at 7:04pm

Chemistry
How much heat would you need to melt 20.0 L of ice that had frozen on a fruit tree.
Saturday, October 11, 2014 at 4:03pm

AP Chemistry
1. If alum is heated at first too strongly causing it to splatter out of the crucible what effect will this have on the determination of the water hydration? 2. If alum is heated insufficiently what effect will this have on the determination of the water hydration? 3. If not ...
Saturday, October 11, 2014 at 3:33pm

CHEMISTRY
Write a balanced chemical equation for the reaction of solid vanadium(V)({\rm V}) oxide with hydrogen gas to form solid vanadium(III)({\rm III}) oxide and liquid water.
Saturday, October 11, 2014 at 2:48pm

CHemistry
Assuming the final concentration of chloride anion after the addition of HCl (precipitation step) was 0.1M, what is the remaining concentration of Ag+ in the solution? (pKsp for AgCl = 9.74)
Saturday, October 11, 2014 at 2:20pm

chemistry
you have not added enough sodium hydroxide to precipitate all the copper as copper hydroxide. How could you tell that not all the copper had precipitated?
Saturday, October 11, 2014 at 2:04pm

chemistry
When a metal was exposed to light at a frequency of 3.86× 1015 s–1, electrons were emitted with a kinetic energy of 3.60× 10–19 J. What is the maximum number of electrons that could be ejected from this metal by a burst of light (at some other frequency) ...
Saturday, October 11, 2014 at 12:32pm

chemistry
how to do a research paper
Saturday, October 11, 2014 at 11:51am

chemistry
What is the percentage yield of the reaction of 4.9 g isoamyl alcohol with 4.9 g of acetic acid if 3.5 g of isoamyl acetate product is obtained after distillation? Enter your answer, without a % symbol, to 2 sig. figs.
Saturday, October 11, 2014 at 3:56am

Chemistry URGENT!!
Which anions have the largest and smallest radii? Thank you!!
Friday, October 10, 2014 at 10:07pm

Chemistry
Which positive ion (cation) has the smallest radius? Please help! Thanks!
Friday, October 10, 2014 at 9:25pm

Chemistry
If 43.2 mL of 2.46 M HClO4 solution completely reacts with a 75.0 mL sample of a sodium hydroxide solution, what is the molarity of the sodium hydroxide solution? (hint: write the complete balanced rxn)
Friday, October 10, 2014 at 9:17pm

chemistry
a solution is made by mixing 38.0 ml of ethanol C2H6O, 62.0mL of water. assuming ideal behavior, what is the vapor pressure of the solution at 20 C
Friday, October 10, 2014 at 9:08pm

Chemistry
Imagine that you have a 7.00L gas tank and a 4.00L gas tank. You need to fill one tank with oxygen and the other with acetylene to use in conjunction with your welding torch. If you fill the larger tank with oxygen to a pressure of 145atm , to what pressure should you fill the...
Friday, October 10, 2014 at 7:29pm

College chemistry
What is the volume in milliliters of 0.1069 M Cr2O72- required to react with 252.4 mL of 0.08013 M Cl- according to the reaction below? 6 Cl-(aq) + Cr2O72-(aq) + 14 H+(aq) ® 3 Cl2(g) + 2 Cr3+(aq) + 7 H2O(l)
Friday, October 10, 2014 at 4:59pm

Chemistry
Many portable gas heaters and grills use propane, C3H8(g). Using enthalpies of formation, calculate the quantity of heat produced when 19.0g of propane is completely combusted in air under standard conditions. Assume that liquid water is forming.
Friday, October 10, 2014 at 4:49pm

Chemistry
Please Help!! I dont know how to balance this redox equation! I've been trying to solve this for hours and I'm getting nowhere Fe(s) + HClO4 (aq) --> H (g) + FeClO4 I tried balancing and I got these Fe(s) + HClO4 (aq) --> H2 (g) + Fe(ClO4)3 and 2Fe(s) + 6HClO4 (...
Friday, October 10, 2014 at 2:05pm

chemistry
Suppose you add a small ice cube to room temperature water in a coffee cup calorimeter. What is the final temperature when all the ice is melted? Assume that you have 200.0 mL of water at 25.0 degrees Celsius and the ice cube weighs 15.0 g and is at 0.0 degrees Celsius before ...
Friday, October 10, 2014 at 1:34pm

Chemistry
If the minimum (threshold) energy for the emission of an electron from the surface of a particular metal is 3.90 X 10-19 J, what is the kinetic energy of an electron emitted from the surface of the metal when it is irradiated by electromagnetic radiation of wavelength 213 ...
Friday, October 10, 2014 at 10:28am

chemistry
100 mL of a 0.1 mM buffer solution made from acetic acid and sodium acetate with pH 5.0 is diluted to 1 L. What is the pH of the diluted solution?
Friday, October 10, 2014 at 7:12am

Chemistry
What is the wavelength of a photon having a frequency of 71.6 THz? So I know 1 THz = 10 to the power of 15 Hz And c= 3 x 10 to the 8th and h= 6.63 x 10 to the -34th
Friday, October 10, 2014 at 2:51am

Chemistry
I have the question find the balanced equation when Fe(s) is placed in HClO4 (aq). How do I balance this redox reaction? I'm not entirely sure its right but the unbalanced equation I have so far is Fe (s) + HClO4 (aq) -->Fe(ClO4)3 + H2 I'm not sure what to do after ...
Friday, October 10, 2014 at 1:19am

chemistry
How many moles of aluminum are presented in a 0.856g sample of aluminum can? Assume that the can is pure aluminum.
Friday, October 10, 2014 at 12:21am

Chemistry
What are the parts of a calorimeter used in chemistry?
Thursday, October 9, 2014 at 9:55pm

chemistry
In the laboratory a student combines 25.9 mL of a 0.223 M magnesium bromide solution with 23.3 mL of a 0.615 M magnesium acetate solution. What is the final concentration of magnesium cation ? ..... M
Thursday, October 9, 2014 at 6:55pm

chemistry
Can you make a 2 carbon molecule of Ketone?
Thursday, October 9, 2014 at 5:31pm

Chemistry
If 14.23 mL of 0.203 M NaOH is required to neutralize .269 g of a monoprotic unknown acid, what is the molecular weight of the unknown acid?
Thursday, October 9, 2014 at 1:07pm

chemistry
How many hydrogen atoms are in 0.0542 mol of H2SO4? Answer in units of atoms H
Thursday, October 9, 2014 at 12:25pm

chemistry
Calculate (a) the moles and (b) the mass of magnesium carbonate at the start if 0.2 moles of sulfuric acid is added to the magnesium carbonate and the excess sulfuric acid made up to a 250 cm3 solution. 25 cm3 of this solution required 0.03 moles of sodium hydroxide for ...
Thursday, October 9, 2014 at 12:22pm

Chemistry
What is the pH of a solution containing both 0.954 M formic acid (HCO2H, Ka = 1.8x10-4) and 1.260 M phenol (HC6H5O, Ka = 1.6x10-10)?
Thursday, October 9, 2014 at 12:12pm

chemistry
A solution is prepared by mixing 4.62 grams of potassium hydroxide in 1.00 L of water. After that, 250.0 mL of a 0.100 M solution of HCl is added to the solution. What is the resulting pH of the final mixture?
Thursday, October 9, 2014 at 12:03pm

chemistry
An aqueous solution of nitric acid is standardized by titration with a 0.121 M solution of calcium hydroxide. If 24.5 mL of base are required to neutralize 15.4 mL of the acid, what is the molarity of the nitric acid solution?
Thursday, October 9, 2014 at 9:21am

Chemistry
How many liters of liquid nitrogen are produced when 360.0 L of nitrogen gas is liquified at 77.36 kl
Thursday, October 9, 2014 at 1:50am

Chemistry
Calculate amount of 1 M acetic acid and 1M sodium acetate necessary to prepare 50 ml of a 0.15 M buffer at ph 4.80. (pka acetic acid =4.74)
Wednesday, October 8, 2014 at 11:29pm

Organic Chemistry
If your carboxylic acid is benzoic acid, how many moles of benzoic acid are present in your sample (0.30g, and it is a mixture of three components of equal mass)?
Wednesday, October 8, 2014 at 11:07pm

chemistry
Experimental Molar Ratio of Copper in CuxOy
Wednesday, October 8, 2014 at 9:58pm

Chemistry
Moles of Copper in the original .825g of Copper Oxide
Wednesday, October 8, 2014 at 9:38pm

chemistry
How many oxygen atoms are in 0.07 mol of dinitrogen pentoxide (N2O5)? Answer in units of atoms
Wednesday, October 8, 2014 at 9:10pm

Chemistry
if all the macro-molecules are made mainly of the elements CHO, how are they different?
Wednesday, October 8, 2014 at 7:07pm

chemistry
20.0 mL of a 2.2 M lead (II) nitrate solution is mixed with 100.0 mL of a 0.75 M magnesium sulfate solution. What is the concentration of nitrate ions in the resulting solution?
Wednesday, October 8, 2014 at 6:41pm

Chemistry
If one assumes the volumes are additive, what is the concentration, in mol/L, of NO3− in a solution obtained by mixing 263 mL of 0.167 M KNO3, 311 mL of 0.404 M Mg(NO3)2, and 713 mL of H2O?
Wednesday, October 8, 2014 at 5:46pm

Chemistry
What volume of 5.0 M H2SO4 should be diluted to 100mL to prepare a 0.25 M H2SO4 M solution? I know the molar mass of H2SO4 is 98g but I'm not sure where exactly that fits in and how I'm supposed to get it to be diluted. Thank you!
Wednesday, October 8, 2014 at 4:33pm

chemistry
A solution of silver perchlorate (AgClO4) is made by dissolving 40.4 g of pure silver perchlorate and diluting it to exactly 140 ml. What is the solutions molarity? Can you just go through the steps of what I need to do? I'm so confused. Thanks
Wednesday, October 8, 2014 at 4:25pm

Chemistry
Calculate how many grams of O2(g) can be produced from heating 37.0 grams of KClO3(s). Formula: 2KClO3 = 2KCl + 3O2
Wednesday, October 8, 2014 at 4:24pm

chemistry
Calculate how much K3Fe(CN)6 [MW: 329.24] you would need to weigh out to make a 1x10-3 M solution dissolved in 0.2 M NaNO3 in a 100 ml volumetric so far i have worked out that 0.329 g will give me the 1x10-3 M, but im confused when it is dissolved into the NaNO3.
Wednesday, October 8, 2014 at 2:31pm

Chemistry
Assign the two absorptions found above 3000 cm-1 in acetamide. Why are these absorptions missing in n,n-dimethylacetamide
Wednesday, October 8, 2014 at 2:28pm

Chemistry
A gas mixture composed of helium and argon has a density of 0.846g/L at a 734mmHg and 298 K. What is the composition of the mixture by volume?
Wednesday, October 8, 2014 at 1:36pm

Chemistry
A 0.700 g sample containing Ag2O and inert material is heated, causing the silver oxide to decompose according to the following equation: 2 Ag2O(s) → 4 Ag(s) + O2(g) If 13.8 mL of gas are collected over water at 27°C and 1.00 atm external pressure, what is the ...
Wednesday, October 8, 2014 at 1:31pm

Chemistry
Give a acid-base pairs which produce Na2CO3 as a salt
Wednesday, October 8, 2014 at 1:22am

Chemistry
A solution of ammonia and water contains 1.60×1025 water molecules and 8.50×1024 ammonia molecules. How many total hydrogen atoms are in this solution?
Wednesday, October 8, 2014 at 1:11am

chemistry
what could cause the difference in the actual number of mole and the expected number of mole in copper oxide?
Tuesday, October 7, 2014 at 11:13pm

chemistry
what is the molar ratio of 0.114 copper to 0.116 oxygen? Then how do you make an empirical formula from this information?
Tuesday, October 7, 2014 at 11:05pm

chemistry
in a empirical formula lab how do you calculate the number of moles of Cu in 0.0114 moles of CuSo4*H2O? Thanks
Tuesday, October 7, 2014 at 10:38pm

Chemistry
---This was the previous one--- Substances A, B, and C can all act as oxidizing agents. In solution, A is green, B is yellow, and C is red. In the reactions in which they participate, they are reduced to A-, B-, and C- ions, all of which are colorless. When a solution of C is ...
Tuesday, October 7, 2014 at 10:36pm

chemistry
A metal rod has a mass of 17.62 g. A graduated cylinder contains 29.9 mL of water. The metal rod is added to the cylinder. The final water level in the cylinder is 36.1 mL. What is the density of the metal rod?
Tuesday, October 7, 2014 at 10:35pm

chemistry 112
A volume of 60.0mL of aqueous potassium hydroxide (KOH) was titrated against a standard solution of sulfuric acid (H2SO4). What was the molarity of the KOH solution if 19.2mL of 1.50 M H2SO4 was needed? The equation is 2KOH(aq)+H2SO4(aq)→K2SO4(aq)+2H2O(​l) Express ...
Tuesday, October 7, 2014 at 10:34pm

Chemistry
Earlier I asked /display.cgi?id=1412727782 (tyvm btw) Say you have these A, B, and C solutions. Now you have an unknown colorless solution that contains either NaA, NaB, or NaC. In solution, each salt dissociates completely into the Na+ ion and the anion A-,B-, or C- (which ...
Tuesday, October 7, 2014 at 10:15pm

Chemistry
A reaction uses 4.5 grams of oxygen and an excess of nitrogen. How many grams of dinitrogen pentoxide are produced?
Tuesday, October 7, 2014 at 10:13pm

chemistry
How many grams are in 2.5 moles of magnesium hydroxide
Tuesday, October 7, 2014 at 9:36pm

Chemistry
The concentration of a certain sodium hydroxide solution was determined by using the solution to titrate a sample of potassium hydrogen phthalate (abbreviated KHP). KHP is an acid with one acidic hydrogen and a molar mass of 204.22 g/mol. In the titration 34.67 mL of the ...
Tuesday, October 7, 2014 at 8:54pm

Chemistry
A student mixes four reagents together, thinking that the solutions will neutralize each other. The solutions mixed together are 50.0 mL of 0.100 M hydrochloric acid, 100.0 mL of 0.200 M of nintric acid,500. mL of 0.0100 M calcium hydroxide, and 200.0 mL of 0.100 M rubidium ...
Tuesday, October 7, 2014 at 8:52pm

Chemistry
Any help would be greatly appreciated! Substances A, B, and C can all act as oxidizing agents. In solution, A is green, B is yellow, and C is red. In the reactions in which they participate, they are reduced to A-, B-, and C- ions, all of which are colorless. When a solution ...
Tuesday, October 7, 2014 at 8:23pm

CHEMISTRY
If you use a dirty buret, the titrant leaves drops of solution behind as the meniscus descends during delivery of the solution. The volume actually delivered by the buret will be __________ the volume your readings of the buret scale indicate was delivered the same as less ...
Tuesday, October 7, 2014 at 7:38pm

Chemistry
A pure white solid material that looks like table salt releases gas when heated under certain conditions. There is no change in the appearance of the solid, but the reactivity of the material changes. Did a chemical or physical change occur? How do you know? Was the original ...
Tuesday, October 7, 2014 at 6:22pm

chemistry
Calculate the air concentration (mol/l) of phenol in equilibrium with solution including 100 g/m3 of phenol.(T=20 C)
Tuesday, October 7, 2014 at 6:04pm

chemistry
An experiment to determine compound partition among air, water, and soil phases was conducted by adding 1 gram of the compound to a reactor that had 1 m3 of air, 0,001 m3 of water0 and 100 g of solid. The reactor was at atmodpheric pressure and at aconstant tepmrature 20 C The...
Tuesday, October 7, 2014 at 6:03pm

chemistry
If the concentration of pure o-xylene in hair above a pool of pure o-xylene is 200 g/m3 at 25 C which direction can o-xylene move vapor pressure of pure o-xylene is 0.00871 atm
Tuesday, October 7, 2014 at 5:50pm

Chemistry
A fictitious element X is composed of 10.0 percent of the isotope 55^X , 20.0 percent of the isotope 56^X , and 70.0 percent of the isotope 57^X . Calculate the weighted atomic mass of element X to the nearest tenth.
Tuesday, October 7, 2014 at 4:30pm

Chemistry
A hot air balloon is filled with 1.23 × 106 L of an ideal gas on a cool morning (11 °C). The air is heated to 121 °C. What is the volume of the air in the balloon after it is heated? Assume that none of the gas escapes from the balloon.
Tuesday, October 7, 2014 at 4:00pm

chemistry
Mass (g) of solute in 179.8 mL of 0.267 M calcium acetate
Tuesday, October 7, 2014 at 3:29pm

Chemistry
I do not know how to solve this problem. Could you show me how? You have a stock solution of 5.00M H3PO4. a.) What would be the concentration if 20.0mL of the stock solution is diluted to 250.0mL? b.) What volume of the dilute solution would you need if you needed 0.0200mol oh...
Tuesday, October 7, 2014 at 1:22pm

Chemistry
The synthesis of zinc iodide was performed using 1.8912g of zinc and 1.5965g of iodine. Determine the limiting reactant and calculate the theoretical yield of zinc iodide in grams.
Tuesday, October 7, 2014 at 12:42pm

Chemistry
What is the enthalpy change for the first reaction? Fe2O3(s) → 2Fe(s) + 3/2O2(g) ΔH = 4Fe(s) + 3O2(g) → 2Fe2O3 (s) ΔH = -1,652 kJ I think I'm supposed to rearrange the equation and double everything but enthalpy isn't my strong suit
Tuesday, October 7, 2014 at 12:19pm

CHEMISTRY 56
Aerosol cans have a label that warns the user not to use them above a certain temperature and not to dispose of them by incineration. Even an empty can contains residual gaseous propellant. For example, the residual pressure in a can is 1.16atm when it is sitting on a shelf at...
Tuesday, October 7, 2014 at 10:27am

CHEMISTRY
what do you observe on the seawater where ships dock? Explain in relation with attractive forces and surface tension..
Tuesday, October 7, 2014 at 12:57am

CHEMISTRY
what do you observe if you drop water to a basin of water? Explain please
Tuesday, October 7, 2014 at 12:56am

chemistry
the reaction of 7.10g carbon with excess O2 yields 12.25g of CO2. what is the percent yield of this reaction? I have tried everything and looked through all of my notes and nothing is working for stiochiometry
Monday, October 6, 2014 at 11:06pm

Chemistry
A given solution contained potassium chloride, KCl, and hydrochloric acid. 25 cm3 of it needed 24.80 cm3 of 0.0986 M sodium hydroxide solution to neutralize the acid, and the neutral solution then required 23.55 cm3 of 0.2 M silver nitrate, AgNO3, solution to precipitate all ...
Monday, October 6, 2014 at 10:15pm

Chemistry
It takes how many ml of 1.5 M NaCl to make 500 ml of .38 M NaCl?
Monday, October 6, 2014 at 10:05pm

chemistry
A 26.6 g sample of an unknown compound contains 0.8 g of oxygen. What is the percent by mass of oxygen in the compound?
Monday, October 6, 2014 at 9:56pm

chemistry
Magnesium combines with oxygen to form magnesium oxide. If 20.07 g of magnesium reacts completely with 6.70 g of oxygen, what is the percent by mass of oxygen in magnesium oxide?
Monday, October 6, 2014 at 9:56pm

chemistry
Copper sulfide is formed when copper and sulfur are heated together. In this reaction, 132 g of copper reacts with 53 g of sulfur. After the reaction is complete, 9 g of sulfur remains unreacted. What is the mass of copper sulfide formed?
Monday, October 6, 2014 at 9:55pm

chemistry
When mercury oxide is heated, it decomposes into mercury and oxygen. If 26.8 g of mercury oxide decomposes, producing 1.8 g oxygen, what is the percent by mass of mercury in mercury oxide?
Monday, October 6, 2014 at 9:52pm

Chemistry
Classify each as carbohydrate, protein, lipid, or nucleic acid. 1. Starch 2. Cholesterol 3. Steroids 4. Glycogen
Monday, October 6, 2014 at 8:15pm

chemistry
How many moles of molecules are in 198 g of hydrogen nitrate (HNO3)? Answer in units of mol
Monday, October 6, 2014 at 8:01pm

Chemistry
The solubility of KNO3 is 80g/100g water at 50 degrees and 10g/100g water at 0 degrees. The solubility of CuSO4 is 60g/100g water at 50 degrees and 20g/100g water at 0 degrees. A mixture contains 13.8g of KNO3 and 1.94g of CuSO4. A) Calculate the minimum mass of water that ...
Monday, October 6, 2014 at 7:52pm

chemistry
A 22.0 g piece of alloy at 264.8°C is dropped into a simple calorimeter that contains 175.0 g of water. The temperature of the calorimeter water increased from 20.4°C to 23.1°C. Calculate the specific heat capacity of the alloy.
Monday, October 6, 2014 at 7:49pm

CHEMISTRY 45
Calculate the average speed of an oxygen gas molecule, O2, at 21.0∘C . ------------------------- How much faster do ammonia (NH3) molecules effuse than carbon monoxide (CO) molecules? --------------------------- Highest rate of effusion to lowest rate He, H2S, C3H8, Ar, H2
Monday, October 6, 2014 at 7:47pm

CHEMISTRY 44
A syringe containing 1.65mL of oxygen gas is cooled from 91.3∘C to 0.5∘C. What is the final volume of oxygen gas? I got 2.19ml???
Monday, October 6, 2014 at 7:45pm

CHEMISTRY 3
Consider the following balanced equation: 2N2H4(g)+N2O4(g)→3N2(g)+4H2O(g) Complete the following table showing the appropriate number of moles of reactants and products. If the number of moles of a reactant is provided, fill in the required amount of the other reactant, ...
Monday, October 6, 2014 at 4:16pm

Principles of Chemistry
A certain amount of chlorine gas was placed inside a cylinder with a movable piston at one end. The initial volume was 3.00 L and the initial pressure of chlorine was 1.30atm . The piston was pushed down to change the volume to 1.00 L. Calculate the final pressure of the gas ...
Monday, October 6, 2014 at 3:38pm

CHEMISTRY 2
A 56.0mL sample of a 0.102 M potassium sulfate solution is mixed with 34.7mL of a 0.114 M lead acetate solution and this precipitation reaction occurs: K2SO4(aq)+Pb(C2H3O2)2(aq)→PbSO4(s)​+2KC2H3O2(aq) The solid PbSO4 is collected, dried, and found to have a mass of...
Monday, October 6, 2014 at 2:07pm

CHEMISTRY 1
What is the correct net ionic equation, including all coefficients, charges, and phases, for the following set of reactants? Assume that the contribution of protons from H2SO4 is near 100 %. Ba(OH)2(aq)+H2SO4(aq)→ Express your answer as a chemical equation. This is what ...
Monday, October 6, 2014 at 2:06pm

chemistry
4. If you were asked to determine the number of atoms in a 52.0 gram sample of carbon, how would you set up the conversion? What is the final answer with correct units?
Monday, October 6, 2014 at 1:30pm

Chemistry
How to convert 24.63cm to nm^2
Monday, October 6, 2014 at 11:06am

Chemistry
Report 2 decimal places and appropriate units, the molar mass of steric acid (C17H35COOH). Please help
Monday, October 6, 2014 at 11:04am

Chemistry
How many moles of steric acid are contained in 0.25mL of a hexane solution containing 5.4x10^-4 grams of steric acid/L? (Hint: g/L x L = g/ (g/mol)=mol). Please show your work. Please help. Thank you
Monday, October 6, 2014 at 11:03am

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