Sunday
May 1, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

College Chemistry
Oxygen has a Henry’s law constant of 1.3*10^-3 mol/kg*bar at 25 °C when dissolving in water. If the total pressure of gas ( gas plus water vapor) over water is 1.00 bar, what is the concentration of O2 in the water in grams per milliliter? (The vapor pressure of water...
Wednesday, February 3, 2016 by Pablo

chemistry
Choose the pair of substances that are most likely to form a homogeneous solution. N2O4 and NH4Cl C6H14 and C10H20 LiBr and C5H12 C6H14 and H2O None of the pairs above will form a homogeneous solution.
Wednesday, February 3, 2016 by reem

Chemistry
a. Calculate the expected freezing-point depression of a 0.200 m KNO3 solution. b. Will the value you calculated match the actual freezing-point depression for this solution? Why or why not? a). -0.372 degrees Celsius b). Possibly because not all of the substance ionizes 100% ...
Wednesday, February 3, 2016 by Drew

Chemistry
If 2.43 grams of aluminum react with excess CuSO4, What is the theoretic yeild of Cu? And then Use the Actucal amount of Cu formed to find percent yield.You have 0.92 mass of copper metal product. 2Al + 3CuSO4 ---> Al2(SO4)3 + 3Cu 2.43 / 27 = 0.09 moles of al 0.09 x 3 / 2 x...
Wednesday, February 3, 2016 by Boberto

Chemistry
Explain in words what is happening in the reaction between copper and silver nitrate.
Wednesday, February 3, 2016 by Anonymous

Chemistry
In a sample of 100 liters of air a city's 2x10^-8 L of the pollutant SO2. How many ppm by volume ?
Wednesday, February 3, 2016 by Sara

chemistry
Propane is used in BBQs and burns according to the following equation: C3H8 + 5O2 -> 3CO2 + 4H2O. If 2.2 moles of carbon dioxide are produced, how many moles of oxygen gas reacted?
Wednesday, February 3, 2016 by Melanie

chemistry
Using the following equation 2C2H2 + 5O2 -> 4CO2 + 2H2O what volume of oxygen would be needed to react with 89.6L of C2H2 at a temp of 273 and a pressure of 101.3 kpa. I can't seem to figure out my first step. Using PV=NRT should I do initial and final conditions? I ...
Wednesday, February 3, 2016 by danielle

chemistry
For the reaction N2(g) + 3H2(g) 2NH3(g), what will happen if more ammonia gas is added?
Wednesday, February 3, 2016 by aaron

Chemistry
which element in the first transition series do not exhibit variation of oxidation state and why?
Wednesday, February 3, 2016 by Ri

Chemistry
in paramagnetic ions all the bonds formed between Mn and O are covalent,why?
Wednesday, February 3, 2016 by Minhye

Chemistry
Why is radius of Fe2+ less than that of Mn2+ ?
Wednesday, February 3, 2016 by Minhye

Chemistry
Why do argon and flourine not form compounds like Xenon Flourides?
Wednesday, February 3, 2016 by Minhye

chemistry
hcl + naoh ==> h2o + nacl limiting reagant
Wednesday, February 3, 2016 by Anonymous

Chemistry
A 1.0 mL volume of 0.010 M H2SO4 is added to a mixture of 6 drops of 0.010 M HIO3, 14 drops of deionized water, and 1 drop of starch solution. A color change in the reaction mixture occurred after 56 seconds. a. Assuming 20 drops per milliliter for all solutions, determine the...
Tuesday, February 2, 2016 by Aly

Chemistry
In interhalogen compounds of the type Ab5 and AB7, B is invariably flourine,why ?
Tuesday, February 2, 2016 by Minhye

AP Chemistry
What is a molecular dipole moment? A. The arrangement of charge around an atom in a nonpolar molecule B. A net cancellation of charge separation due to symmetry of the molecule C. A separation of charge characterizing a nonpolar covalent molecule D. A separation of charge ...
Tuesday, February 2, 2016 by FIFI

chemistry
He has narrowed the identity of his unknown to either molecule X, molecule Y, or molecule Z. The Merck Index tells him that all three molecules produce white, needle-like crystals from ethanol. How might he definitively identify his unknown molecule?
Tuesday, February 2, 2016 by Sean

Chemistry
7.5 L of hydrogen gas at STP and zinc (II) nitrate was produced by reacting zinc with nitric acid. Calculate the mass of zinc needed for this reaction. This is what I did: Zn + 2HNO3 = H2 + Zn(NO3)2. 7.5L H2 * 1 mole H2/ 22.4 L H2 * 1 mole Zn/ 1 mole H2 * 65.4 g Zn / 1 mole Zn...
Tuesday, February 2, 2016 by Anna Diaz

Chemistry
Kc = 28 at some temperature for the reaction H2(g) + I2(g) ⇀↽ 2 HI(g). If 16.7 moles of HI are introduced into a 10.0 liter vessel, how many moles of I2 are present at equilibrium? Answer in units of mol.
Tuesday, February 2, 2016 by Katie

Chemistry
The heat of vaporization of water is 9.73 kcal/mol. At what pressure (in torr) would pure water boil at 89◦C?
Tuesday, February 2, 2016 by Katie

chemistry
Crushing Can: youtube video: /watch?v=SBpqT-u8sjo 1. Explain why the can collapsed using the Combined Gas Law where T1 is the initial temperature of the air inside the can before the can was inverted and T2 is the temperature of the air inside the can after it was plunged into...
Tuesday, February 2, 2016 by help me please! :\

Chemistry
Using calculations, determine how you would make a 525 ml pg a 0.50 M solution of Cl- ions using CaCl2. I am unsure how to do this question, I was going to use C1V1=C2V2 but with this I would be missing the first part of the equation. If that is the case, would I assume the ...
Tuesday, February 2, 2016 by Heather

chemistry
How many moles of carbon dioxide will be created by the complete combustion of 2.25 moles of ethane?
Tuesday, February 2, 2016 by caleb

Chemistry
The National Vaccine Information Center estimates that 90% of Americans have had chickenpox by the time they reach adulthood. We now consider a random sample of 120 American adults: a) Would you be surprised if there were 105 people who have had chickenpox in their childhood? ...
Monday, February 1, 2016 by Anonymous

Chemistry
Assume the reaction of 55.25 g of Ge in the following reaction to determine the other quantities. 3Ge + 2N2 -> 1Ge3N4
Monday, February 1, 2016 by Kaitlyn

Chemistry
The elements 57 through 71 (Lanthanum and the Lanthanoids) all form Ln+3 ions in aqueous solution. These all have an electron configuration is [Xe]4fn, where n increases from zero to fourteen over the series from Lanthanum to Lutetium Select the two ions that have 4 unpaired ...
Monday, February 1, 2016 by Kaitlyn

chemistry
Crushing Can: youtube video: /watch?v=SBpqT-u8sjo 1. Explain why the can collapsed using the Combined Gas Law where T1 is the initial temperature of the air inside the can before the can was inverted and T2 is the temperature of the air inside the can after it was plunged into...
Monday, February 1, 2016 by help me please! :\

Chemistry
Answer the following questions using this balanced chemical equation. 2C3H6+9O2+6H2O How many grams of C3H6 are needed to produce 4.2 mol of H2O?
Monday, February 1, 2016 by Alana

chemistry
A metal tank contains three gases: oxygen, helium, and nitrogen. If the partial pressu of the three gases in the tank are 5 atm of O2, 900 mm Hg of N2, and 1.4 kPa of He what total pressure inside of the tank?
Monday, February 1, 2016 by karen

Chemistry
Write a balanced equation for the following reaction. Use whole number coefficients and subscripts as appropriate. Carbon tetrachloride is an industrial liquid solvent. It is made by combining methane gas with elemental chlorine. These react to form carbon tetrachloride and ...
Monday, February 1, 2016 by Mike

Chemistry
A 1" x 1" 1/8" copper ingot has a density of 8.94 g/mL. 25 pellets were obtained from the ingot. Explain what would be the density of each pellet. I went ahead and found the mass of the ingot which is 1.1175g but I'm still stumped on what to do from there.
Monday, February 1, 2016 by Joe

chemistry
Write a balanced equation for the following reaction. Use whole number coefficients and subscripts appropriately. When hydrochloric acid is mixed with sodium hydrogen carbonate, the mixture fizzes. The fizzing occurs because the reaction produces a gas, namely carbon dioxide. ...
Monday, February 1, 2016 by Mike

chemistry
What is law of mass action
Monday, February 1, 2016 by Mukesh shankopal(koli)

chemistry
A sample of gas at 300 K has a volume of 2.0 liters. At what temperature will the volume decrease to 1.0 liter if the pressure is kept constant?
Monday, February 1, 2016 by shelbie

Chemistry
A Se-75 source is producing 310 rem at a distance of 3.0 m. What is the distance needed to decrease the intensity of exposure to below 25 rem, the level at which no effects would be detectable.
Monday, February 1, 2016 by Michelle

Chemistry
Of the following (a through e), which increase and which decrease, as the strength of the attractive noncovalent interactions increases? Explain. a) Deviations from the ideal ga law b) Boiling Temperature c) Sublimation temperature d) Vapor Pressure e) The energy it takes to ...
Sunday, January 31, 2016 by Anonymous

chemistry
if 15 grams of ethane gas c2h6, reacts with 128 g oxygen un a combustion reaction, how many moles of water can be produced?
Sunday, January 31, 2016 by jen

Chemistry
look at any mole, what is the ratio of particles of the numerator compared to the number of particles in the denominator?
Sunday, January 31, 2016 by Charlie

chemistry
Silver chloride was formed when 10.10g of silver trioxonitrate(v) reacts with 14.10g of sodium chloride to form 9.58g of sodium trioxonitrate(v),write out the balance equation
Sunday, January 31, 2016 by Esther

Chemistry
A weather balloon is inflated with helium to a volume of 28.1 L at a pressure of 754 torr and a temperature of 26.0 Celsius. The balloon rises in the atmosphere to an altitude where the pressure is 380 torr and the temperature is -16.1 degree Celsius. 1. Calculate the number ...
Sunday, January 31, 2016 by Anonymous

Chemistry
A 1.0 L ball containing Ar at 5 atm is connected to a 10.0 L ball containing N2 at 2 atm. a) Calculate the partial pressure and mole fractions of argon and nitrogen after the valve is opened and the gases are allowed to mix (they fill the balls on both sides). b) What is the ...
Sunday, January 31, 2016 by Anonymous

Chemistry
Calculate the mass of Mg needed to produce ~40 mL of H2. how do I do this?
Sunday, January 31, 2016 by Anon

Chemistry
In the preparation of one liter of 2.5 M HCl solution, what is the volume of HCl concentrated (37% w / w, d = 1.19 g / ml) to be used?
Sunday, January 31, 2016 by Sara

Chemistry
what is the concentration of 0.009 M solution of nh3 at 25 degree fahrenheit?
Sunday, January 31, 2016 by Jewel

Chemistry
What are the correct IUPAC names for triisopropylmethane and 2,2-dimethylcyclopentane?
Sunday, January 31, 2016 by Hayley

chemistry titration (check my thought process)
can someone check my answers here for my lab... so i have 3.234*10-4 moles of ca2+ and mg2+ ions and used 0.02450L of edta so my molarity of both ions is 0.01320 M. and now we had to find calcium, i used 0.01655 L of edta, can i use the same # of moles (3.234*10^-4) to find ...
Saturday, January 30, 2016 by Anonymous

Chemistry
Would you expect H 2 SO 3 to be oxidized to H 2 SO 4 in our natural environment? Please explain using the molecules in our environment and the concept of oxidation states.
Saturday, January 30, 2016 by Nick

AP Chemistry
Which of the following is true about lanthanides? A. they are all radioactive B. they are highly electropositive C. they are very common elements D. they have low melting and boiling points
Friday, January 29, 2016 by Stephanie

Chemistry
Please check. HCl: dipole-dipole interaction HF: hydrogen bonding TiCl4: ionic bonding? CsCl:ionic bonding
Friday, January 29, 2016 by Sanaya

Chemistry
Determine the concentration of H + ions from an aqueous solution of nitrous acid (HNO2) 0.02 mol / L, knowing the degree of ionization of the acid is 3%
Friday, January 29, 2016 by Shania

Chemistry
51J of heat added to an aluminum can with a mass of 25.5 g what is temperature change if specific heat capacity is 0.903 J/ g degrees Celsius?
Friday, January 29, 2016 by Anonymous

Chemistry
Can enzymes be called Polymers ?
Friday, January 29, 2016 by Miicchi

Chemistry
Dr.Bobb222 please help balance the following oxidation-reduction reactions, which occur in acidic solution, using the half-reaction method. (Use the lowest possible coefficients. Include states-of-matter under the given conditions in your answer.) (a) NO3−(aq) + Pb(s) &#...
Friday, January 29, 2016 by Joanaleine Ferrera

chemistry
If 20 mole of potassium react with an excess of lithium sulfate , how many moles of potassium sulfate can you expect to form. porassium phosphate to potassium sulfate: 20 x 2 kaso4 x 174.259 / 212.267 /2 = 16.4188498448 lithium sulfate to potassium sulfate: 62 x 2kaso4 x 174....
Thursday, January 28, 2016 by Boberto

chemistry
if 10.3 lithium sulfate react with an abundant amount of potassium phosphate, what mass of lithium phosphate can you expect to isolate? lithium sulfate to lithium phosphate : 10.03 x 3 li3PO4 x 115.79 Lipo4 / 109.94 liSo4 / 3 LiSo4 = 10.9016179159 potassium phosphate to ...
Thursday, January 28, 2016 by Boberto

chemistry
How much water could you make? blanced equation : 4 C7H5N3O6 + 5 O2 = 6 N2 + 12 CO2 + 10 H2O + 16 C.
Thursday, January 28, 2016 by Boberto

Intro to Chemistry
2 Na + 2 H20 --> 2 NaOH + H2 is this the balanced equation? and How do I find calulate the % yield of the products?
Thursday, January 28, 2016 by Kimmy

Intro to Chemistry
Balanced Equation C3H8 + 5 02-->3 CO2+ 4H20 Calculate the % yield of the products. How do I do this?
Thursday, January 28, 2016 by Kimmy

chemistry
Consider the reaction Select a possible mechanism for the reaction. Step1:2X2Y+Z2→2X2YZ (slow)
Thursday, January 28, 2016 by Tayebeh Asadi

chemistry
Consider the reaction Select a possible mechanism for the reaction. Step1:Step2:2X2Y⇌X4Y2 (fast)X4Y2+Z2→2X2YZ (slow)
Thursday, January 28, 2016 by Tayebeh Asadi

chemistry
Consider the reaction Select a possible mechanism for the reaction. Step1:Step2:X2Y+Z2→X2YZ2 (slow)X2YZ2→X2YZ+Z (fast)
Thursday, January 28, 2016 by Tayebeh Asadi

chemistry
Consider the reaction Select a possible mechanism for the reaction. Step1:Step2:X2Y+Z2→X2YZ+Z (slow)X2Y+Z→X2YZ (fast)
Thursday, January 28, 2016 by Tayebeh Asadi

chemistry
Consider the reaction Select a possible mechanism for the reaction. Step1:Step2:Step3:Z2→Z+Z (slow)X2Y+Z→X2YZ (fast)X2Y+Z→X2YZ (fast)
Thursday, January 28, 2016 by Tayebeh Asadi

chemistry
Consider the reaction 2 X2Y+Z2 ⇌ 2 X2YZ which has a rate law of rate= k[X2Y][Z2] Select a possible mechanism for the reaction.
Thursday, January 28, 2016 by Tayebeh Asadi

Analytical chemistry
The hydrogen sulfide in a 79.168 g sample of crude petroleum was removed by distillation and collected in a solution of CdCl2. The precipitated CdS was then filtered, washed and ignited to create CdSO4. Calculate the percentage of H2S in the sample if 0.122 grams of CdSO4 was ...
Thursday, January 28, 2016 by Sam

General Chemistry
I have been going at part B of this problem for a few hours. I've completed an ice table and calculated the total number of moles based off pressure but am still unable to come up with the partial pressures. If someone could provide the steps for solving I would appreciate...
Thursday, January 28, 2016 by Duke

Chemistry 101
A spherical bass has a diameter of 1.00 inch and a mass of 2.00 grams. Will the ball float or sink water? Remember that if the ball's density if greater than 1.00 g/mL the density of water, the ball will sink. Also remember to use dimensional analysis.
Thursday, January 28, 2016 by Lilly

Chemistry 101
A piece of metal weighing 10.65 grams releases 3450 joules of heat energy when it is cooled from 99.9c to 28.5c. Wheat is the specific heat capacity of the metal in J/g c..
Thursday, January 28, 2016 by Lilly

Chemistry 101
A rectangular prism has these dimensions and mass: length = 12.6 cm,, width = 1.256 feet, and thickness = 456 mm. Its mass is 1.2347 pounds. Determine its density in g/cm^3.
Thursday, January 28, 2016 by Lilly

chemistry
A given mass of gas has a volume of 7.5dm at 250k and 80kmm3,calculate the pressure at which it will have a volume of 7.2dm3 at 270k?
Thursday, January 28, 2016 by Blessing

Chemistry
A student has placed a mixture of CaO and CaO, 4.88 g of dough into a flask containing 1.46 L of carbon dioxide at 35 ° C and 746 mmHg. After completing the reactions, it found that CO2 pressure had decreased to 353 mmHg.Calcule the percentage composition of the mixture
Thursday, January 28, 2016 by Emma

Chemistry
If 0.812g of calcium reacts in a coffee-cup calorimeter that contains 400.0g of water/ The initial temperature of the water is 17.9°C, the final temperature is 26.0°C. Calculate the standard molar enthalpy change for this reaction.
Thursday, January 28, 2016 by Gem

Chemistry
Construct a Born Haber cycle for the formation of calcium oxide showing clearly using equations, the steps of the enthalpy stages involved
Thursday, January 28, 2016 by Demario

Chemistry
Question from text: "The reaction between phosphorus and chlorine is described by the equation, P4(s) + 6 Cl2(g) ↔ 4 PCl3(l). At equilibrium, the concentration of Cl2 is found to be 0.87 M. Calculate Keq." Keq = [PCl3]^4 / [P4] [Cl2]^6 I am not seeing how to ...
Thursday, January 28, 2016 by Jennifer

Chemistry
What is the volume of the container needed to store 0.8 moles of argon gas at 5.3 atm and 227°C? (Given: R = 0.08205 l · atm/mol · K)
Thursday, January 28, 2016 by Abigail

Chemistry
Given that ΔH (fusion) of water is 6025 J/mol, Cp,m(ice) = 37.7 J K–1 mol–1, and Cp,m(water,liquid) = 75.3 J K–1 mol–1, calculate ΔG (in J) for the freezing of 89 moles of water at 1 atm pressure and the constant temperature T = 14.4 °C. I got...
Thursday, January 28, 2016 by Brian

Chemistry
Crystal of Sodium form Cubic unit cell with edge length 430pm.Find the no.of atoms present per unit cell and also the type of unit cell. P.S. No radius or density is given so its a lil bit tough dan the rest... Plz Help ASAP !!
Wednesday, January 27, 2016 by Minhye

chemistry
A graduated cylinder was used to measure out 5.3 mL of a sample of a liquid into a pre-weighed 100-mL beaker (mass of the beaker = 24.568 g) at 25oC. The total mass of the beaker and alcohol was 29.568 g. what is the actual volume transferred from the graduated cylinder to the...
Wednesday, January 27, 2016 by clememnce

Chemistry
Calculate the mass percent of water in the hydrate Al2(SO4)3·18H2O to four sig. figs. I got this answer 60.23, but I just am confused on how to correctly write the units
Wednesday, January 27, 2016 by Anonymous

chemistry
Describe the circumstances in which the following processes could be used to separate the components of a mixture. -sublimation -crystallization -evaporation of a solvent from a solution -dissolving of an impure substance in a solvent
Wednesday, January 27, 2016 by cara

Chemistry
Culd i get a reference to the formulae used in Solid State ?? (Like the no.of atoms in a face centred cubic cell is 4 Etc )
Wednesday, January 27, 2016 by Minhye

Chemistry
Which of the following has the lowest conductivity when dissolved ? F2, H2O, MgO, or LiCl
Wednesday, January 27, 2016 by Anonymous

Chemistry
How much oxygen is needed to form 50 grams of water?
Wednesday, January 27, 2016 by Majaliwa

Chemistry 102
Using your average value for Kc (6.92x10^2) and the concentrations provided for the reactants (0.00111mol/L for both), determine the absorbance expected when a 16.00mL of Fe3+ is reacted with 10.00ml of SCN and measured in a 1.00cm cuvette.
Wednesday, January 27, 2016 by Taylor

Chemistry
Assuming that the Bohr model is valid, what is the kinetic energy of a photoelectron liberated by a photon with a the given wavelength from a state with given Z and n? If the available energy is insufficient to break the tether, enter 0. λ=320 nanometers from a state with...
Wednesday, January 27, 2016 by Kaitlyn

Chemistry
If each balloon is filled with carbon dioxide gas at 20 degrees C and 1 atmosphere, calculate the mass and the number of moles of carbon dioxide in each balloon at maximum inflation. Use the ideal gas law in your calculation. The volume of the balloon at maximum inflation is ...
Wednesday, January 27, 2016 by Cindy Avalos

Chemistry
If each balloon is filled with carbon dioxide gas at 20 degrees C and 1 atmosphere, calculate the mass and the number of moles of carbon dioxide in each balloon at maximum inflation. Use the ideal gas law in your calculation. Someone please let me know the answer! Thank you so...
Wednesday, January 27, 2016 by Cindy Avalos

Chemistry
I have been plagued by this question for a good half an hour, whilst doing past papers I came across it- ' EXPLAIN why the value of Kw increases as the temperature increases' as far as I can tell, it is about the excess production of OH- and H+ from le chateliers ...
Wednesday, January 27, 2016 by A

Chemistry 101
A chemist needs 2.00 grams of a liquid compound with a density of 0.785 g/cm^3 density. what volume of compund is required?
Wednesday, January 27, 2016 by Lilly

Chemistry
how do you make 400 ml pf 2 Osm solution of Mg CL2?
Wednesday, January 27, 2016 by dee

Chemistry 101
if an organic liquid has a density of 1.11 g/mL and has a measured volume of 500. mL, what mass of liquid is present?
Wednesday, January 27, 2016 by Lilly

Chemistry 101
A chemist needs 2.00 grams of a liquid compound with a density of 0.785 g/cm^3 density. what volume of compund is required? Mass= Volume X Density 2.00g x 0.785 g/Cm^3 = 1.57g/cm^3 Not sure is this is correct......
Wednesday, January 27, 2016 by Lilly

Chemistry
aCETYLENE REACTS WITH OXYGEN GAS TO PRODUCE CARBON DIOXIDE GAS AND WATER VAPOR
Wednesday, January 27, 2016 by Brandon

chemistry
if 100g of calcium carbonate on heating produces 44g of carbon dioxide,how much calcium oxide will be formed?
Wednesday, January 27, 2016 by suja

Chemistry
[10:58am]: Wn 4.5g of liquid water was formed by burning hydrogen gas in oxygen,-72kj of heat was given off.calc d standad heat formation of water
Wednesday, January 27, 2016 by Hayur

Chemistry
You have 10.5 moles of C5H12, how many moles of C do you have?
Wednesday, January 27, 2016 by cici

Chemistry
If each balloon is filled with carbon dioxide gas at 20 degrees C and 1 atmosphere, calculate the mass and the number of moles of carbon dioxide in each balloon at maximum inflation. Use the ideal gas law in your calculation. Someone please let me know the answer! Thank you so...
Wednesday, January 27, 2016 by Cindy Avalos

Chemistry
Combusting 44.8L of H2 with 22.4 L O2 (both at STP) results in the formation of 44.8 L of H2O if the reaction is maintained at the same conditions (STP) and goes to completion. Given the heat of formation of water (= -241.8 kK/mol) calculate a) the PV work b) the heat evolved ...
Tuesday, January 26, 2016 by Sanaya

Chemistry
How many moles of oxygen will be produced by 0.27 moles of potassium chlorate? 2 KCLO3 = 3 O2 + 2 KCL 0.27 x 3 O2 / 2KCL = 0.405?
Tuesday, January 26, 2016 by Boberto

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