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September 30, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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chemistry
A gas with a volume of 6.65 L at a pressure of 1.22 atm is allowed to expand until the volume raises to 54 L. What is the new pressure (in atm)?
Sunday, February 23, 2014 at 2:57am

college chemistry
After 94.995 seconds the concentration of A was reduced from 0.3688 M to 0.1464 M. What is the first order rate constant?
Saturday, February 22, 2014 at 5:52pm

chemistry
A room contains 48 kg of air. How many KWh of energy are necessary to heat the air in the house from 7oC to 28oC? The heat capacity of air is 1.03 J/goC
Saturday, February 22, 2014 at 4:59pm

chemistry
If a satellite orbits the earth at a velocity of 2.9 x 103 km/hr, this would be the same as how many in/sec?
Saturday, February 22, 2014 at 4:45pm

chemistry
How would you prepare a solution of about 8mg/100ml of ascorbic acid in water (25ml)? I'm not sure if they mean to use that ratio of ascorbic acid in water to make a 25 ml solution or if the wording means something else.
Saturday, February 22, 2014 at 4:23pm

Chemistry
A volume of 5oo ml of potassium sodium tartrate solution S1 of c1=0.21mol/l is to prepared. Determine the mass of hydrated potassium sodium tartrate of formula KNaC4H4O6.4H2O needed for this preparation .(molar atomic masses : H=1;C=12;O=16;Na=23;K=39)
Saturday, February 22, 2014 at 2:46pm

chemistry
What is the mass of a sample of ammonia that contains 0.750 moles of hydrogen atoms? The answer is 4.26g, but I do not know how to set up the equation.
Saturday, February 22, 2014 at 10:55am

Science
How does the silly putty made up of glue gel differ from the silly putty made of soap in terms of texture ? How would the touch be different and why? Chemical structure? .....? Science:Chemistry - bobpursley, Friday, February 21, 2014 at 9:53pm Have you made the two masses? ...
Friday, February 21, 2014 at 10:04pm

Science:Chemistry
How does the silly putty made up of glue gel differ from the silly putty made of soap in terms of texture ? How would the touch be different and why? Chemical structure? .....?
Friday, February 21, 2014 at 9:43pm

organic chemistry
Once it has been opened, and particularly if ithas been left open to the air, a bottle of aspirin may develop a vinegar-like odor.How this might happen?
Friday, February 21, 2014 at 9:10pm

organic chemistry
What is the condensed structural formula of methyl 2-aminobenzoate?
Friday, February 21, 2014 at 8:58pm

Chemistry
What are the concentrations of HSO4- and SO42- for a 0.0050 M sulfuric acid solution? We are trying to find x but not sure how to find it on the calculator, please help!!!
Friday, February 21, 2014 at 8:00pm

chemistry
WRITE DOWN REACTION OF HYDROLYSIS OF NH4NO2 IN NET IONIC FORM. INDICATE REACTION OF MEDIUM.
Friday, February 21, 2014 at 7:22pm

Chemistry
Light travels at a speed of 3.00 times 10^10 cm/s. What is the speed of light in kilometers/hour?
Friday, February 21, 2014 at 6:30pm

Chemistry
An atom of gold has a mass of 3.271 times 10^-22g. How many atoms of gold are in 5.00g of gold?
Friday, February 21, 2014 at 6:28pm

Chemistry
What conversion factor would you use to convert cubic decimeters to milliliters?
Friday, February 21, 2014 at 6:26pm

chemistry
How would you prepare a solution of about 8mg/100ml of ascorbic acid in water (25ml)?
Friday, February 21, 2014 at 5:41pm

Chemistry
How many molecules of nitrogen are in 22.4 L of nitrogen at exactly 0 C and 3 atm?
Friday, February 21, 2014 at 5:25pm

Chemistry
What would be the density of Hydrogen gas at 500 C and 0.76 atm?
Friday, February 21, 2014 at 5:24pm

chemistry
By how much will the vapor pressure of water decrease if a solution at 40.0°C is produced by dissolving 16.0212 g of K3PO4 (formula mass = 212.30 g/mol) with 40.8480 g of water. The vapor pressure of pure water at this temperature is 55.30 mmHg. If the solute is ionic, ...
Friday, February 21, 2014 at 3:36pm

Chemistry
In a 1.0 x10-6 M of HNO3 (aq) at 25 degrees celsius identify the relative molar amounts of theses species HNO3- H3O+ OH- NO3- H2O
Friday, February 21, 2014 at 2:51pm

Chemistry 2
A solution of NaOH (aq) contains 8.2 grams of NaOH(s) per 100.0 mL of solution. Calcualte Ph and POH at 25 degrees celsiuis
Friday, February 21, 2014 at 2:30pm

Chemistry
a mixture of 10cm^3 of C5H12 and 0.084g of C12H24 was passed with an excess of oxygen. after cooling to room temperature, the reaidual gas was passed through aqueous potassium hydroxide. what volume was absorbed by the alkali
Friday, February 21, 2014 at 2:25pm

Chemistry 2
Calcualte PH and POh of an aqueous solution that is 0.050 M in HCL and 0.085 M in HBr at 25 degrees C
Friday, February 21, 2014 at 2:23pm

Chemistry 2
Calculate Kp for the reaction C(s)+CO2(g)<-->2CO(g) kp=? C(s)+2H2O(g)<--->CO2(g)+2H2 kp1=3.47 H2(g)+CO2(g)<--->H2O(g)+CO(g) kp2=0.735
Friday, February 21, 2014 at 1:30pm

college chemistry
Rubidium metal, Rb, crystallizes in a body-centered cubic arrangement. What is the radius of one atom of Rb, if its density is 1.5320 g/cm3?
Friday, February 21, 2014 at 1:27pm

Chemistry
A+2B--->2C Kc=2.27 2c--->D Kc=0.144 Calculate the equilibrium constant for the reaction D--->A+2B
Friday, February 21, 2014 at 1:18pm

Chemistry
How much water would I need to add in order to dilute 200mL of a 5 M solution down to 2 M?
Friday, February 21, 2014 at 12:17pm

Chemistry
For the reaction given, the value of the equilibrium of the constant at 400 K is 7.0. Br2(g)+ Cl2(g)=2BrCl(g) Does the: Reaction proceed to the left? Reaction proceed to the right? Partial pressure represent a system in an equation?
Friday, February 21, 2014 at 10:44am

Chemistry
determine the amount of water formed in 4NH3 + 5O2 4NO + 6H2O if 10 g of Oxygen is mixed with 10g nitrigen trihydride in grams
Friday, February 21, 2014 at 10:43am

Chemistry
120.0g of ice is melted, how much energy is absorbed?
Friday, February 21, 2014 at 9:04am

chemistry
How much heat is released when 28.95g of water is frozen?
Friday, February 21, 2014 at 9:04am

Chemistry
AgNO3 + NaCl → AgCl + NaNO3 . How many grams of NaCl would be required to react with 446 mL of 0.211 M AgNO3 solution? Answer in units of grams
Friday, February 21, 2014 at 12:10am

chemistry
What is the percent yield of NaCl if 31.0 g of CuCl2 reacts with excess NaNO3 to produce 21.2 g of NaCl?
Thursday, February 20, 2014 at 10:43pm

Chemistry
Aerosol cans contain com- pressed gases that, when released, help propel the contents out of the can. Why is it important to keep aerosol cans from overheating?
Thursday, February 20, 2014 at 10:39pm

chemistry
The reaction of fluorine with ammonia produces dinitrogen tetra fluoride and hydrogen fluorida. 5F2(g)+2NH(g)---> N2F4(g)+6HF(g) A. If you have 66.6gNH3, how many grams of F2 are required for a complete reaction? B. how many grams of NH3 are required to produce 4.65g HFCS? ...
Thursday, February 20, 2014 at 10:21pm

chemistry
(a) The measured pH of a 0.200 M HBr solution at 25°C is 0.806. Calculate the activity coefficient for H . (b) The measured pH of a 0.200 M HNO3 solution at the same temperature is 0.822. Calculate the activity coefficient for H in this solution.
Thursday, February 20, 2014 at 9:38pm

chemistry
What volume of 1.00 M NaOH would be required to neutralize 77.4 mL of 5.4 M HCl? Round to two places after the decimal point and keep it in mL
Thursday, February 20, 2014 at 8:47pm

Chemistry help
A ground state hydrogen atom absorbs a photon of light having a wavelength of 93.77 nm. It then gives off a photon having a wavelength of 94 nm. What is the final state of the hydrogen atom?
Thursday, February 20, 2014 at 8:43pm

AP Chemistry
For 2 SO2(g) + O2(g) equilibrium reaction arrow 2SO3(g), Kp = 3.0 104 at 700. K. In a 2.00-L vessel the equilibrium mixture contains 1.11 g of SO3 and 0.106 g of O2. How many grams of SO2 are in the vessel
Thursday, February 20, 2014 at 8:36pm

Chemistry
How do you find the [OH-] of a 1x10^-3 M solution of NH4Cl?
Thursday, February 20, 2014 at 8:28pm

Bio Chemistry
There are two main ways in which molecules are transported into and out of cells - active transport and passive transport. Which of the following statements is true of passive transport?
Thursday, February 20, 2014 at 8:21pm

Chemistry
Three people weigh on a standard mass of 2.00 g on the same balance. Each person obtains a reading of 7.32 for the mass of the standard. These results imply that the balance that was used is ___________. a) neither accurate nor precise b) accurate c) precise d) accurate and ...
Thursday, February 20, 2014 at 8:01pm

Chemistry
1. Calculate the pH for each of the following cases in the titration of 25.0 mL of 0.240 M pyridine, C5H5N(aq) with 0.240 M HBr(aq): (a) before addition of any HBr (b) after addition of 12.5 mL of HBr (c) after addition of 22.0 mL of HBr (d) after addition of 25.0 mL of HBr (e...
Thursday, February 20, 2014 at 7:06pm

Chemistry
Consider the two equilibria: BaF2=Ba2+ + 2F- Ksp=1.7x10^(-6) F- + H20=HF + OH- Kb=2.9x10^(-11) Determine the solubility of BaF2 at pH=5? What I'm mostly confused about is how to determine if F- is dominant or if you have to take HF into account while doing your calculations.
Thursday, February 20, 2014 at 6:50pm

chemistry
How many enthalpy changes (ÄH’s) would be required to calculate the total enthalpy change when ice at 0.0oC is turned to steam at 100.0oC?
Thursday, February 20, 2014 at 6:40pm

Chemistry
Christian Brothers Brandy (80%, 1.7 L) what do I do with this problem it's a percent compostion work sheet
Thursday, February 20, 2014 at 6:24pm

AP Chemistry
For 2 SO2(g) + O2(g) equilibrium reaction arrow 2SO3(g), Kp = 3.0 104 at 700. K. In a 2.00-L vessel the equilibrium mixture contains 1.11 g of SO3 and 0.106 g of O2. How many grams of SO2 are in the vessel
Thursday, February 20, 2014 at 6:19pm

Chemistry
I have 500 mL of a 6.0 M solution that I want diluted down to 2 M. How many mL of water should I add to the solutiion. " FOR EVERY PROBLEM YOU MUST DRAW A PICUTRE"
Thursday, February 20, 2014 at 6:18pm

Chemistry
If I leve 750 mL of 3.6 sodium chloride solution uncoverd and 150 mL of the solvent evaporates overnight, what is the new solution concentration?
Thursday, February 20, 2014 at 6:08pm

chemistry
if I dilute 250 of mL of 2.4 M lithium hydroxide solution so that it's new volume is 750 mL, what is the concentration of the solution? 
Thursday, February 20, 2014 at 6:06pm

Chemistry
how do i figure out the valences for elements in the transition elements section in the periodic table of elements (i need it for doing nomenclature) and how do i figure out the valences if i don't have the periodic table of elements examples: Zn Cu Ni Co Fe Mn Cr V Ti Sc
Thursday, February 20, 2014 at 5:25pm

Chemistry
Write the total and net ionic equations for the following molecular reaction: HgNO3 (aq) + NaCl (aq) -> HgCl (s) + 2 NaNO3 (aq)
Thursday, February 20, 2014 at 2:17pm

chemistry
An aqueous solution of HCl has a concentration of .160m and a density of 1.0691 g/mL. What is the concentration of HCl as molarity?
Thursday, February 20, 2014 at 2:12pm

Chemistry
Assign oxidation numbers to each individual element in the following reaction and identify the oxidizing and reducing agents. 2 Zn S + 3 O2 -> 2 S O2 + 2 Zn O Ox#: Zn=+2 S=-2 O=-2 -> S=+2 O=-2 Zn=+2 O=2 Is that correct? I'm not sure how to identify the oxidizing and ...
Thursday, February 20, 2014 at 2:11pm

Chemistry
Calculate the Ph and POH of an aqueous soltuion that is 0.500 M in HCl(aq) and 0.085 M in HBr (aq) at 25 degrees C.
Thursday, February 20, 2014 at 10:54am

Chemistry
Given the equation CaO + H2O = Ca(OH)2 if you start with 1.86 moles of CaO, how many moles of Ca(OH)2 will result?
Thursday, February 20, 2014 at 9:11am

Chemistry
A compound is known to be a cesium halide, CsX. If 3.00 grams of the salt is dissolved in exactly 100.0 grams of water, the solution freezes at -0.735°C. What is the chemical formula for the salt? i know it would be -0.735= -1.86 * m m= 3g/ X g/mol/kg solvent however the ...
Thursday, February 20, 2014 at 9:00am

Chemistry
Calculate the concentration of IO3– in a 9.23 mM Pb(NO3)2 solution saturated with Pb(IO3)2. The Ksp of Pb(IO3)2 is 2.5 × 10-13. Assume that Pb(IO3)2 is a negligible source of Pb2 compared to Pb(NO3)2.
Thursday, February 20, 2014 at 2:16am

Chemistry
A compound is known to be a cesium halide, CsX. If 3.00 grams of the salt is dissolved in exactly 100.0 grams of water, the solution freezes at -0.735°C. What is the chemical formula for the salt?
Thursday, February 20, 2014 at 1:52am

Chemistry
At noon on a clear day, sunlight reaches the earth\'s surface at Madison, Wisconsin, with an average power of approximately 7.00 kJ·s–1·m–2. If the sunlight consists of photons with an average wavelength of 510.0 nm, how many photons strike a 8.40 ...
Wednesday, February 19, 2014 at 10:33pm

College Chemistry
If a 375 mL sample of water was cooled from 37.5°C to 0°C, how much heat was lost (in joules)
Wednesday, February 19, 2014 at 7:44pm

College Chemistry
A 150.0 mL sample of a 1.50 M solution of CuSO4 is mixed with a 150.0 mL sample of 3.00 M KOH in a coffee cup calorimeter. The temperature of both solutions and the calorimeter was 25.2°C before mixing and 31.3°C after mixing. The heat capacity of the calorimeter is ...
Wednesday, February 19, 2014 at 7:43pm

chemistry 112
the formation of SO3 from so2 and o2 is an intermediate step in the manufacture of sulfuric acid, and it is also responsible for the acid rain phenomenon. the equilibrium constant Kp for the reaction is 0.13 at 830 degree celcius. in one experiment, 2.00 mol so2 and 2.00 mol ...
Wednesday, February 19, 2014 at 7:15pm

chemistry
The density of gold is 19.31g/cm3 and the density of platinum is 21.43 g/cm3. If equal masses of gold and platinum are transferred to equal volumes of water in separate graduated cylinders which graduated cylinder would have greatest volume change
Wednesday, February 19, 2014 at 5:53pm

chemistry
The compound sodium sulfate is soluble in water. When this compound dissolves in water, which ion listed below would be present in solution?
Wednesday, February 19, 2014 at 4:08pm

Chemistry
How many molecules (not moles) of NH3 are produced from 3.65x10-4g of H2?
Wednesday, February 19, 2014 at 1:01pm

Chemistry
How many grams of H2 are needed to produce 12.88g of NH3?
Wednesday, February 19, 2014 at 12:57pm

Chemistry help
How many grams if nh3 can be produced from 2.57mol of n2 and excess h2?
Wednesday, February 19, 2014 at 12:53pm

chemistry
a compound contains only carbon hydrogen and oxygen analysis of a sample showed that it contained by mass 53.4% carbon and 11.1% hydrogen . what is the simplest formula for this compound .. step by step plese
Wednesday, February 19, 2014 at 10:46am

Chemistry URGENT
Please show how N and O are combined to make NO^+2 in Lewis dot structure. I'm having a hard time. Thanks
Wednesday, February 19, 2014 at 9:51am

Chemistry
P4 + 5O2 P4O10 , 1.5 moles of product were made in 30 seconds. What is the rate of reaction?
Wednesday, February 19, 2014 at 7:37am

chemistry
What is the molarity of a solution with a volume of 974 mL containing 17 g of CuSO4?
Tuesday, February 18, 2014 at 6:56pm

Chemistry
Calculate the heat in kilojoules needed to vaporize 8.00kg of water at 100∘C.
Tuesday, February 18, 2014 at 5:22pm

chemistry
You have a solution that contains 340ml of water and 20ml of ethanol. Find the concentration of ethanol in this solution in each of the following units: (density of water is 1.00 g/ml, density of ethanol is 0.789g/ml)
Tuesday, February 18, 2014 at 5:02pm

Chemistry
The molarity of H3PO4 is .01 M. The density of the H3PO4 in the solution is .0009 g/mL. What is the mass percent of H3PO4 in the solution, which has a density of 1.11 g/ml?
Tuesday, February 18, 2014 at 4:27pm

Chemistry
What is the volume ofCO2 measured at S.T.P which is involved on heating10.5g of NaHCO3
Tuesday, February 18, 2014 at 3:36pm

Chemistry
Solutions of NiSO4(aq), Al2 (SO4)3 (aq), CoSO4 , and SnSO4 (aq) are in bottles labelled A, B, C, and D. a) Design an experiment to identify which ionicsulfate solution is in which bottle. Give a list of equipment and chemicals required. Describe a step-by-step procedure for ...
Tuesday, February 18, 2014 at 12:55pm

chemistry
What is the molality of a solution composed of 28.4 g of methanol CH3OH and 250 g of water
Tuesday, February 18, 2014 at 12:03pm

chemistry
was the formation of reactants or products favored by the addition of heat?
Tuesday, February 18, 2014 at 10:24am

Chemistry
A 150.0 mL sample of a 1.50 M solution of CuSO4 is mixed with a 150.0 mL sample of 3.00 M KOH in a coffee cup calorimeter. The temperature of both solutions and the calorimeter was 25.2°C before mixing and 31.3°C after mixing. The heat capacity of the calorimeter is 24...
Tuesday, February 18, 2014 at 9:43am

CHEMISTRY
Hi!! pls i need help! 1) Mg + Al2(So4)3 2)Fe + CuSO4 3)Mg + CuSO4 4)Zn + CuSO4 5)Mg + FeSO4 FOR ALL 5: a)balanced eq b)ionic equation c) net ionic
Tuesday, February 18, 2014 at 6:57am

Chemistry
Hi!! pls i need help! 1) Mg + Al2(So4)3 2)Fe + CuSO4 3)Mg + CuSO4 4)Zn + CuSO4 5)Mg + FeSO4 FOR ALL 5: a)balanced eq b)ionic equation c) net ionic PLEASE HELP ME..THERE ARE SOO MANY MORE QUESTIONS I NEED TO DO!!!:(
Tuesday, February 18, 2014 at 3:47am

CHEMISTRY
0.15g of hydrogen chloride (HCl) is dissolved in water to make 6.5L of solution. What is the pH of the resulting hydrochloric acid solution?
Monday, February 17, 2014 at 11:21pm

Chemistry
in a chemical reaction, 5.2 grams of magnesium reacts with hydrogen nitrate. Calculate the amount of magnesium nitrate that is produced and the amount of hydrogen nitrate needed to react with the magnesium.
Monday, February 17, 2014 at 6:48pm

Chemistry Help Please!!!
1) Boric acid, H3 BO3, is a triprotic acid that dissociates in three reactions. The first dissociation step is: H3BO3 ⇌ H^+ + H2BO3^-, K(a1) = 7.3 x 10^-10; the second dissociation step is: H2BO3^- ⇌ H^+ + HBO3^-2, K(a2) = 1.8 x 10^-13; and the third dissociation ...
Monday, February 17, 2014 at 6:48pm

chemistry
Except for rubidium and caesium,___
Monday, February 17, 2014 at 4:11pm

chemistry
how many moles of vapor can be produced for 52 g of O2
Monday, February 17, 2014 at 1:56pm

college chemistry
The solubility of Ar in water at 321.9 torr is 0.02538 g/L. What is Henry's Law constant (M/atm) for Ar in water?
Monday, February 17, 2014 at 12:34pm

chemistry
I am stuck on this one and was wondering if anyone can help me out! Why does sodium nitrate (166.5) have a bigger molar entropy than sodium bromide (86.8)? Thanks!
Monday, February 17, 2014 at 12:32pm

Chemistry
write a sentence for the following reaction PCl5(s)=PCl3(s)+Cl2(g)
Monday, February 17, 2014 at 1:21am

Chemistry
Equation: Fe+CuCl2>FeCl2+Cu We put two iron nails into the copper chloride solution:1. mass of empty dry beaker:103.64 2. mass of two iron nails, before reaction:1.20 3. mass of two iron nails after reaction: 1.01 4. mass of beaker and copper (dry):104.4 Through ...
Sunday, February 16, 2014 at 11:08pm

AP Chemistry
Approximately how much water should be added to 10.0 mL of 12.4 M HCl so that it has the same pH as 0.90 M acetic acid (Ka = 1.8 10-5)?
Sunday, February 16, 2014 at 10:16pm

Chemistry
Consider the equation A(aq) + 2B(aq) 3C(aq) + 2D(aq). In one experiment, 45.0 mL of 0.050 M A is mixed with 25.0 mL 0.100 M B. At equilibrium the concentration of C is 0.0410 M. Calculate K.
Sunday, February 16, 2014 at 10:10pm

Chemistry
If the tongs used in the experiement were made of pure iron, what might happen if the tongs were allowed to remain in contact with the CuCl2 solution?
Sunday, February 16, 2014 at 9:59pm

Chemistry
Equation: Fe+CuCl2>FeCl2+Cu The ratio of moles of copper produced to moles of iron reacted should be 1:1,but I get 60:17 in lab,can you state at least 3 errors for me?
Sunday, February 16, 2014 at 9:48pm

Chemistry
1. A student uses 6M HCl solution contaminated with Al(NO3)3 to wash the nichrome wire in between recordings of emission spectra for the different known and unknown metal ion solutions. The emission energies for the aluminum are 3.90x10^-19 J/atom, 3.58x10^-19 J/atom, and 2....
Sunday, February 16, 2014 at 9:25pm

Chemistry
Fe2O3(s) + 2Al(s)-> 2Fe(l) + Al2O3(s) What is the theoretical yield of iron if we begin the reaction with 10.5 g of Al (assume an excess of Fe2O3)
Sunday, February 16, 2014 at 8:18pm

Chemistry check and help
so for all the chemical formulas if there is no subscript (for the valency of the element) does it mean it is a one or do i have to find the valency on the periodic table of elements? ex. P02 the P for Phosphorus doesn't have a number does it mean it is a one then ex.SO3 ...
Sunday, February 16, 2014 at 7:45pm

AP Chemistry
The rate of effusion of unknown gas X is found to be about 1.5 times that of SF6 gas (MW=146 g/mol) at the same conditions of temperature and pressure. What is the molecular weight of gas X? Answer in units of g/mol
Sunday, February 16, 2014 at 7:03pm

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