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October 25, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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chemistry
At a certain temperature, Keq is 4.13 x 10^-5 for the equilibrium: 2IBr(g) ↔ I2(g) + Br2(g) Assume that the equilibrium is established at the above temperature by adding only the reactant to the reaction flask. What are the concentrations of I2 and Br2 in equilibrium ...
Thursday, June 5, 2014 at 12:20pm

Chemistry
A gas occupies a volume of 140 mL at 35.0 C and 97 kPa. What is the volume of the gas at STP? N = ( P )( V ) / ( R ) ( T ) N = ( 97.00 ) ( 140 /1000 ) / ( 8.314 ) ( 308.15 ) = 0.005300 gmol V sub STP = ( N ) ( R ) ( T sub STP ) / ( P sub STP ) V sub STP = (0.005300 )( 8.314...
Thursday, June 5, 2014 at 12:16pm

Chemistry
A gas has a volume of 590 mL at a temperature of –55.0 C. What volume will the gas occupy at 30.0 C? V1T1 = V2T2 (590 mL)(-55.0C) / (30.0C) = 1081.67 mL 273 + (-55) = 218 K 590/218 = V2/303 V2 = 590 (303/218) = 820 ml Is my work and answer correct??
Thursday, June 5, 2014 at 12:10pm

chemistry
IF ALL NITROGEN ATOMS FROM .1 MOLE nO2 AND .2 MOLE N2O4 ARE REMOVED THEN HOW2 MANY MOLES OF N2 CAN BE PREPARED FROM IT?
Thursday, June 5, 2014 at 11:10am

chemistry
if all the oxygen from 1.8 gram glucose and 9.8 H2So4 are removed and converted to o2 how many moles are prepared?
Thursday, June 5, 2014 at 11:06am

chemistry
how many carbon atoms are present in a drop of ink which falls on the paper having a wave point 0.1 mg
Thursday, June 5, 2014 at 11:02am

chemistry
what is the weight in kg of 3*10 22 molecules of NaOH
Thursday, June 5, 2014 at 11:00am

chemistry
if all the sulphur atoms from 9.8 kgh2so4 are removed and converted to s8 than how many moles of s8 can be prepared?
Thursday, June 5, 2014 at 10:58am

chemistry
if+all+nitrogen+atoms+from+.1+mole+No2+a​nd+.2+N2o4+are+removed+then+how+many+mol​es+of+n2+can+be+prepared+from+it
Thursday, June 5, 2014 at 10:54am

Chemistry
Explain why this reaction is not feasible:CH3CHO^-Na^+ + CH3C(CH3)2Cl=CH3CH2O(CH3)2OCH3. ;->Becos of ion charge of Oxygen and Na in the cpd reacting with non ionic cpd
Thursday, June 5, 2014 at 10:32am

Chemistry
how many moles of oxygen are needed to react with 3.5 moles of isopropyl alcohol, C3H7OH
Thursday, June 5, 2014 at 7:22am

Chemistry
Give reasons why the reaction between benzoylchloride and methanol do not attack carbon from the ring
Thursday, June 5, 2014 at 3:34am

chemistry
a scuba driver is using eanx32, an enhanced nitrox gas mixture. this mixture contains 32% oxygen with 68% nitrogen. if the cylinder is at a pressure of 250 kpa, what is the partial pressure of oxygen?
Thursday, June 5, 2014 at 2:40am

Chemistry
Question: Calculate the solubility (g/L) of CuBr at 25 degrees celsius in 0.0110 M CoBr2. Ksp of CuBr = 5.3*10^-9. I am capable of doing it in pure water, but I am struggling with how the two bromines in CoBr2 will affect the answer and ICE TABLE set up. Thank you!
Wednesday, June 4, 2014 at 11:51pm

Chemistry
The heat capacity of aluminum is 24.4 J/mol times degrees C. How much energy is released when 5.00 g Al is cooled from 50 degrees C to 30 degrees C. a) 2440 J b) 90 J c) 3.7 J d) 488 J I said A, but the answer sheet says that the answer is B. Can someone please explain how ...
Wednesday, June 4, 2014 at 9:52pm

Chemistry
I'm really confused on this question so if someone could show the steps and how to get the answer, that would be great. I understand that you would use delta T=Kbm, but don't know how to use the equation to find the answer. Thanks!! Calculate the boiling point of a ...
Wednesday, June 4, 2014 at 8:29pm

chemistry
15G OF NACL OCCUPY A VOLUME OF 75 Ml what is the molarity solution ?
Wednesday, June 4, 2014 at 7:58pm

chemistry
A sample of helium has a volume of 235 ml and a pressure of 565 mm Hg. What will be the pressure if the helium is compressed to 215 mL (T constant)
Wednesday, June 4, 2014 at 4:44pm

chemistry
If you mix 50 grams of NaHCO3 in 2.0 liters of water, calculate molarity & molality
Wednesday, June 4, 2014 at 7:47am

chemistry
A sample contains Hydrogen atom ,He+ ion, Li2+, & Be3+ ion. In H atom electron is present in 8th orbit, in He2+ e- is present in 6th orbit, Li2+ in 5th orbit& in Be3+ electron is present in 4th orbit. All the atoms are de-excited to the ground state. Calculate the total no. of...
Wednesday, June 4, 2014 at 4:36am

Chemistry
Why is it that the reaction between benzoyl chloride and methanol do attack carbon from the ring
Wednesday, June 4, 2014 at 3:19am

Chemistry
If 87.3 mL of 0.225M KOH solution is mixed with 44.4 mL of 0.313M H2SO4 solution, would the resulting mixture be acidic, basic or neutral?
Tuesday, June 3, 2014 at 11:42pm

chemistry
What is the molarity of a 28.9 g of CaCl2 dissolved in water to make up 0.78L of solution?
Tuesday, June 3, 2014 at 11:06pm

chemistry
Calculate the molarity (M) of AlCl3 in a solution prepared by adding 0.750 L of 0.7 M AlCl3 and 0.250 L of 0.1 M AlCl3 . Assume volumes are additive
Tuesday, June 3, 2014 at 8:35pm

Chemistry
Label each of the following as endothermic or exothermic A.) Products are more stable than reactants B.) Kinetic energy is converted into potential energy C.) Evaporation D.) Combustion E.) Water freezes F.) Heat seems to disappear
Tuesday, June 3, 2014 at 8:04pm

Chemistry
Check my answer please? A reaction requires 22.4 L of gas at STP. You have 45.0 L of gas at 100 kPa and 373 K. Which of the following statements is true? The gas constant is 8.31 L-kPa/mol-K. You will have an excess of gas and the reaction will occur. <--------- You will ...
Tuesday, June 3, 2014 at 7:38pm

Chemistry
I posted this question before and the answer is suppose to be 6.8 L but I keep getting 6.12 L dinitrogen pentoxide n2o5 decomposes by a first-order decomposition in chloroform solvent to yield NO2 and O2. The rate constant at 45°C is 6.2 x 10^-4 mins^-1. Calculate the ...
Tuesday, June 3, 2014 at 7:07pm

Chemistry
I: The standard reaction free energy at equilibrium is zero. II: A reaction stops when the equilibrium is reached. III: An equilibrium reaction is not affected by increasing the concentrations of products. Which of these statements is/are true?
Tuesday, June 3, 2014 at 4:19pm

Chemistry
Consider the reaction HCHO(g) *) H2(g) + CO(g). 1.0 mol of HCHO, 1.0 mol of H2 and 1.0 mol of CO exist in equilibrium in a 2.0 L reaction vessel at 600C. a) Determine the value of the equilibrium constant Kc for this system. 2.0 moles of HCHO and 1.0 mol of CO are then ...
Tuesday, June 3, 2014 at 4:17pm

chemistry
Calculate the molality of sulphuric acid solution in which mole fraction of water is .85
Tuesday, June 3, 2014 at 3:34pm

Chemistry
Calculate the heat formation: 4NH3(g)+502(g)+6H2O(l) ↑ ↑ ↑ Small numbers that go on the bottom. (Sorry, I do not have such a good phone)
Tuesday, June 3, 2014 at 3:17pm

Chemistry
Complete and balance the reactions A) (CH3)2NH(aq)+CH3COOH(aq)→ B) CH3CH2NH2(aq)+HBr(aq)→ C) CH3NH2(aq)+HCOOH(aq)→
Tuesday, June 3, 2014 at 3:03pm

Algebra 1
1. A chemistry student needs to make a solution that is 70% water and 30% hydrochloric acid. The student's current mixture of 300 ml is 60% water and 40% hydrochloric acid. How much water must the student add to achieve his desired solution? A: ? 2. 5. 2/t + 4/3t = 4/t + 2...
Tuesday, June 3, 2014 at 2:11pm

Algebra 1--Please, help me!
Please, will someone check my answers and help me solve the other questions? 1. It takes Dustin 2 hours to shovel the snow from his driveway and sidewalk. It takes his sister 3 hours to shovel the same area. How long will it take them to shovel the walk if they work together? ...
Tuesday, June 3, 2014 at 1:26pm

Algebra 1--Please, help me!
1. It takes Dustin 2 hours to shovel the snow from his driveway and sidewalk. It takes his sister 3 hours to shovel the same area. How long will it take them to shovel the walk if they work together? A: Working together, Dustin and his sister can shovel the walk in 1 1/5 hours...
Tuesday, June 3, 2014 at 12:41pm

Chemistry
dinitrogen pentoxide n2o5 decomposes by a first-order decomposition in chloroform solvent to yield NO2 and O2. The rate constant at 45°C is 6.2 x 10^-4 mins^-1. Calculate the volume of O2 obtained from the reaction of 1.00 mol N2O5 at 45°C and 770 mmHg after 20.0 hours...
Tuesday, June 3, 2014 at 11:48am

Chemistry
Which of the following is true about indicators? A. They are weak acids or bases. B. They are as accurate as a pH meter. C. They maintain their colors across the range of pH values for which they are used. D. all of the above is it A???
Tuesday, June 3, 2014 at 11:19am

Chemistry
The conjugate acid in the reaction described in HCl(g) + NH3(aq) → NH4 +(aq) + Cl- (aq) is A. HCl(g). B. NH3(aq). C. NH4+ (aq). D. Cl-(aq). I think its B or C?
Tuesday, June 3, 2014 at 10:58am

Algebra 1 (Reiny)
1. It takes Dustin 2 hours to shovel the snow from his driveway and sidewalk. It takes his sister 3 hours to shovel the same area. How long will it take them to shovel the walk if they work together? A: Working together, Dustin and his sister can shovel the walk in 1 1/5 hours...
Tuesday, June 3, 2014 at 10:11am

Chemistry
dinitrogen pentoxide n2o5 decomposes by a first-order decomposition in chloroform solvent to yield NO2 and O2. The rate constant at 45°C is 6.2 x 10^-4 mins^-1. Calculate the volume of O2 obtained from the reaction of 1.00 mol N2O5 at 45°C and 770 mmHg after 20.0 hours...
Tuesday, June 3, 2014 at 1:55am

Chemistry
The potassium salt of benzoic acid, potassium benzoate, KC7H5O2, can be made by the action of potassium permanganate on toluene, C7H8. C7H8 + 2 KMnO4 --> 2MnO2 + KOH + H2O If the yield of potassium benzoate cannot be realistically be expected to be more than 71%, what is ...
Tuesday, June 3, 2014 at 12:48am

Chemistry
The first order rate constant is 1.87 x 10^-3 min^-1 at 37°C for reaction of cisplatin. Suppose the concentration of cisplatin in the bloodstream of a patient is 4.73 x 10^-4 mol/L. Calculate the concentration exactly 24 hours later.
Tuesday, June 3, 2014 at 12:20am

Chemistry
How many grams of commercial C2H4O2 (97% pure by mass) must be allowed to react with an excess of PCl3 to produce 50.0g of C2H3OCL if the reaction has a 70% yield? 3C2H4O2 + PCl = 3C2H3OCl + H3PO4
Monday, June 2, 2014 at 9:45pm

Chemistry
are these molecules polar or nonpolar? 1. [PO4] 3- 2. [NO2]- 3. SO3
Monday, June 2, 2014 at 6:10pm

Chemistry
can you please tell me if I have the correct molecule type PO4 3- polar SO3 polar NO2- polar BrCl polar
Monday, June 2, 2014 at 6:01pm

Chemistry
I would like to make sure these answers are correct, the question is what kind of molecule are the following H2 nonpolar HBr polar BrCl polar NH3 polar CCl4 nonpolar
Monday, June 2, 2014 at 5:40pm

Chemistry
please say if molecule is polar or nonpolar: H2 HBr BrCl CS2 H2S
Monday, June 2, 2014 at 5:35pm

Chemistry
If vapour density of gas 32g and occupies a volume of 560cm cube find the mass of the gas also determine its number of molecule
Monday, June 2, 2014 at 4:44pm

Chemistry!!
Complete and balance the reaction of A) (CH3)2NH(aq)+CH3COOH(aq)→ B) CH3CH2NH2(aq)+HBr(aq)→ C) CH3NH2(aq)+HCOOH(aq)→
Monday, June 2, 2014 at 1:35pm

Chemistry
Can anyone name the following alcohol H3C-CH2-CH2-CH2-OH
Monday, June 2, 2014 at 1:25pm

Chemistry. HELP.
You react 25.0 liters of oxygen gas at STP with 50.0 ml of ethanol liquid. Ethanol has a density of 0.789 g/ml. The excess reactant is: -C2H5OH -O2 -CO2 -H2O -C -H2 -CO
Monday, June 2, 2014 at 9:01am

chemistry
Redox reaction in assign oxidation number is ca3(po4)2
Monday, June 2, 2014 at 6:18am

chemistry
make a list of appliances based on the concept of vapourisation and latent heat of vapourisation with uses and principals also
Monday, June 2, 2014 at 2:14am

Chemistry
a) Which of the following reagents would oxidize Zn to Zn2 , but not Ag to Ag ? Answers are: Co2+ Ca2+ Br2- Br2 Co or Ca b) Which of the following reagents would oxidize Ag to Ag , but not Cl– to Cl2? Answers are: Co Br- Br2 Co2+ Ca2+ or Ca
Monday, June 2, 2014 at 12:19am

chemistry
340. mL of hydrochloric acid (HCl) acid is exactly neutralized with 500. mL 0.700 M NaOH solution. What is the concentration of the acid solution?
Sunday, June 1, 2014 at 11:13pm

chemistry
If 5.6 grams of potassium hydroxide is added to enough water to make 950 ml of solution, what is the concentration of the potassium?
Sunday, June 1, 2014 at 10:04pm

physical chemistry
What is the Enthalpy of Decomposition of liquid Hydrogen peroxide (in kJ/mol)?
Sunday, June 1, 2014 at 9:57pm

Chemistry
Find the number of moles of particles for NaCl
Sunday, June 1, 2014 at 6:48pm

Analytical Chemistry
How much ml of 0.200 m of KSCN will be needed after addition of 30.0 ml 0.1100 of AgNO3 to 0.3658 g KI dissolved in 100 ml water?(Ksp= 8.3*10^(-17)for AgI
Sunday, June 1, 2014 at 6:50am

chemistry
how many particles of water are made when 6.2 grams of methanol are consumed
Sunday, June 1, 2014 at 1:09am

Chemistry
Write the formula for a complex formed between Ni 2+ and NH3, with a coordination number of 5. Write the formula for a complex formed between Ni 2+ and CN–, with a coordination number of 4. I am having trouble with these problem because I don't really understand what ...
Sunday, June 1, 2014 at 12:36am

chemistry
What is the significance of atomic nuclear decay? What is your analysis on the societal implications of using this process?
Saturday, May 31, 2014 at 10:01pm

Chemistry
If 56 mL of 1.93 M hydrochloric acid is mixed with water to create a solution with a concentration of 0.9 M , how many liters of water were added?
Saturday, May 31, 2014 at 7:18pm

Chemistry
Fish breathe the dissolved air in water through their gills. Assuming the partial pressures of oxygen and nitrogen in the air are to be .20 atm and .80 atm respectively, calculate the mole fractions of oxygen and nitrogen in the air dissolved in water at 298 k. The ...
Saturday, May 31, 2014 at 6:50pm

Chemistry
Chemistry and engineering topics how chemistry relates to engineering for my 10 page research paper
Saturday, May 31, 2014 at 6:00pm

Chemistry
How many moles of KF are contained in 244 mL of 0.135 m KF solution? The density of the solution is 1.22 g/mL.
Saturday, May 31, 2014 at 5:16pm

Chemistry
At 20°C, an aqueous solution that is 18.0% by mass in ammonium chloride has a density of 1.0512 g/mL What is the molarity of ammonium chloride in the solution?
Saturday, May 31, 2014 at 4:44pm

Chemistry
the solubility of 1-butanol in water is 7.9g per 100g of water. What is the maximum amount of 1-butanol that will dissolve in 5.9g of water
Saturday, May 31, 2014 at 3:57pm

Chemistry
a sulfuric acid solution that is 65.0 h2so4 by mass has a density of 1.55 g/mL. What is the molality of sulfuric acid in this solution
Saturday, May 31, 2014 at 3:18pm

Chemistry
What is the mass percent of an aqueous sodium hydroxide solution in which the molality of NaOH is 6.25m? The density of the solution is 1.2219 g/mL
Saturday, May 31, 2014 at 1:45pm

Chemistry
A sulfuric acid solution that is 65.0% H2SO4 by mass has a density of 1.55 g/mL at 20°C. What is the mass of h2so4 per liter of solution?
Saturday, May 31, 2014 at 1:09pm

chemistry
What volume would the gas occupy if P2 = 0.29 P1? Answer in units of mL
Friday, May 30, 2014 at 8:42pm

chemistry
A gas has a volume of V1 = 565 mL. If the temperature is held constant, what volume would the gas occupy if P2 = 16 P1? Answer in units of mL
Friday, May 30, 2014 at 8:39pm

chemistry
You react 25.0 liters of oxygen gas at STP with 50.0 ml of ethanol liquid. Ethanol has a density of 0.789 g/ml. After actually running the reaction you determined the percent yield was only 78.5%. How many LITERS of CO2 did you make? (Must put CO2 in answer la
Friday, May 30, 2014 at 11:07am

chemistry
A solution of Al2 (SO4) 3 {d=1.253gm/ml } contain 22% salt by weight. The molarity, normality, and molality of the solution is?
Friday, May 30, 2014 at 4:28am

chemistry
you wish to combine two samples, one sample contains is solid water at 0 degree celsius.The other sample contains liquid water at 0 degree celsius,you want to combine both raise the temperature to 100 degree celcius but boil off only 50 ml to gas phase keep the rest as liquid....
Friday, May 30, 2014 at 1:06am

chemistry
you wish to combine two samples, one sample contains is solid water at 0 degree celsius.The other sample contains liquid water at 100 degree celsius,you want to combine both raise the temperature to 100 but boil off only 50 ml to gas phase keep the rest as liquid.How much ...
Friday, May 30, 2014 at 12:51am

chemistry
you wish to combine two samples, one sample contains is solid water at 0 degree celsius.The other sample contains liquid water at 100 degree celsius,you want to combine both raise the temperature to 100 but boil off only 50 ml to gas phase keep the rest as liquid.How much ...
Friday, May 30, 2014 at 12:20am

Chemistry
A sample of hydrogen gas is collected by water displacement at 20.0'C when the atmospheric pressure is 99.8kPa. What is the pressure of the dry hydrogen, if the partial pressure of water vapour is 2.33kPa at that temperature?
Friday, May 30, 2014 at 12:07am

Chemistry
A tank of chlorine gas contains 25.00 kg of pressurized liquid chlorine. If all the chlorine is released in its gaseous for at 17'C and 0.98atm, what volume does it occupy?
Friday, May 30, 2014 at 12:04am

chemistry
you wish to combine two samples, one sample contains is solid water at 0 degree celsius.The other sample contains liquid water at 100 degree celsius,you want to combine both raise the temperature to 100 but boil off only 50 ml to gas phase keep the rest as liquid.How much ...
Thursday, May 29, 2014 at 11:59pm

chemistry
If the mass of copper wire used in your reaction was only 0.012 grams, but the amount of silver nitrate used was unchanged, then how many grams of silver metal could be produced?
Thursday, May 29, 2014 at 7:25pm

Chemistry
Which of the following explains why there are so many differences in the properties of peptides and proteins? A) several amino acid sequences are possible for proteins and peptides B) some proteins are enzymes while others are not C) proteins and peptides include nitrogen D) ...
Thursday, May 29, 2014 at 5:42pm

Chemistry
indium-115 has a half life of 4.5 hours, if you start with a 12.0mg sample of indium-115, how much will remain after 13.5 hours
Thursday, May 29, 2014 at 5:37pm

Chemistry II
How long would it take to consume 13 mg of magnesium in 4.2 mL of 1.25 M HCl? Explain.
Thursday, May 29, 2014 at 5:26pm

Chemistry II
How long would it take to consume 13 mg of magnesium in 4.4 mL of 1.25 M HCl? Explain.
Thursday, May 29, 2014 at 3:56pm

Chemistry
A sample of gas at a pressure of 1.5 atm has a volume of 22.4 L. What is the new volume if the pressure is lowered to 0.75 atm?
Wednesday, May 28, 2014 at 9:35pm

Chemistry
Did I break this up correctly? NaHclO3 breaks into Na+ and HClO3-, and that further breaks into H+ and ClO3-
Wednesday, May 28, 2014 at 9:21pm

chemistry
what will be the pH of a solution NaOH with the concentration 2,2.10mol
Wednesday, May 28, 2014 at 5:56pm

chemistry
NaHclO3 breaks into Na+ and HClO3-, and that further breaks into H+ and ClO3-, is that right?
Wednesday, May 28, 2014 at 5:06pm

chemistry
I say unsaturated. Am I right?
Wednesday, May 28, 2014 at 4:51pm

chemistry
) A chemist dissolves 1.000 x 103 g of potassium hydroxide in enough water to make 1.5 L of stock solution. The chemist later wants 2.00 x 102 mL of 0.10 M potassium hydroxide. How much stock solution does the chemist need in order to make this second solution?
Wednesday, May 28, 2014 at 10:16am

chemistry
CH4+2O2====>2H2O+CO2.calculate the mass of CO2 and H2O formed by combustion of 64g of CH4.
Wednesday, May 28, 2014 at 12:41am

Chemistry
At a temperature of 23.0 degrees celcius, and a pressure of 2.25 bar what volume would 23.0 g of a compound in the gaseous state with a molecular mass of 207 g/mol occupy?
Tuesday, May 27, 2014 at 9:38pm

Chemistry
When magnesium hydrogen carbonate reacts with sulfuric acid, would you consider that an exothermic reaction because it forms CO2 (gas)?
Tuesday, May 27, 2014 at 9:05pm

chemistry
Something that will lower the freezing point of water to -3.7 degrees Celsius if one mole were placed in 1000 grams of water? To solve this I know I have to use the equation Tf= IKfm, Tf= 3.7, but how I go about the problem there if I don't know Kf or the the mole of ...
Tuesday, May 27, 2014 at 8:50pm

chemistry
If 4.8 liters of a 2.8 M solution of NaCl then the solution will have *Blank* moles of NaCl dissolved in it.
Tuesday, May 27, 2014 at 8:27pm

Chemistry
The motor is connected from it's battery and used as a generator.On the axes(vertical is amps and horizontal is time) show the type of current it provides when it is rotated through 2 complete revolutions
Tuesday, May 27, 2014 at 8:17pm

Chemistry
CH3−CH2−CH2−O−CH​2−CH2−CH2−CH2−CH​3 Spell out the full name of the compound
Tuesday, May 27, 2014 at 6:34pm

Chemistry
Complete and balance the following (CH3)2NH(aq)+CH3COOH(aq)→ CH3CH2NH2(aq)+HBr(aq)→ CH3NH2(aq)+HCOOH(aq)→
Tuesday, May 27, 2014 at 6:33pm

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