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July 31, 2015

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
Consider two non-interacting Fermions (half-integer spin) confined in a “box” of length L. Construct the antisymmetric wave functions and compare the corresponding groundstate energies of two systems; one with particles of identical spin and the other with particles ...
Tuesday, March 3, 2015 by lolo

Chemistry Help
How many moles of hydrogen atoms are there in 178 mL of 0.20 M H2SO4? Write your answer in scientific notation. Please help
Tuesday, March 3, 2015 by annoymous

Chemistry Dr. Bob
Balanced Equation: 2PbS+ O2 --> 2PbO +2SO2 How many grams of oxygen are required to react with 0.124mole lead(II) sulfide? Ummmm.. I tried to convert it to grams? 0.124 mol * molar mass of PbS (239.3) = 29.67 g of PbS then tried to plug it into the equation.. 1/2 * 29.67/...
Tuesday, March 3, 2015 by Jennie

Chemistry
For the titration of 50.00mL of 0.1000 M ammonia with 0.1000 M HCl, calculate the pH (a) before the addition of any HCl solution (b) after 20.00mL of the acid has been added
Tuesday, March 3, 2015 by Anonymous

Chemistry
Ok, I'm trying my best here, I'm learning, and I'm thinking I'm on a roll, until I can't get the right answer again..... First.. the butane question Calculate the mass of Butane needed to produce 82.7g Carbon dioxide. 2C4H10 +13 O2--->10H2O +8CO2 Ratio ...
Monday, March 2, 2015 by Jennie

chemistry
1. You are given a mixture containing two compounds, A and B. Both compounds have a solubility of 1 g/ 100 mL of solvent at 20 °C and 16 g/ 100 mL of solvent at 100 °C. The sample is composed of 3.5 g of A and 10 g of B. At 100 °C the entire sample just dissolves ...
Monday, March 2, 2015 by Jon

college chemistry
We did not find any results for 'An automobile gasoline tank holds 23.0 gal when full. How manypounds of gasoline willit hold if the gasoline has a density of 0.737 g/ml?
Monday, March 2, 2015 by kristy

Chemistry
The dosage of technetium -99m for a lung scan is 20 uci/ kg of body weight. How many millicuries should be given to a 50.kg patient (1 mci=1000uci)
Monday, March 2, 2015 by Dee

Chemistry
If 16.5 grams of the base were used in the neutralization of *question 7*, how many grams of acid must have been used to neutralize the base? *neutralization of Na2CO3* ---------------- Would the answer be 16.5g of acid? I was thinking that the acid and base should be the same...
Monday, March 2, 2015 by Anonymous

Science // Chemistry
How many grams of KOH are needed to make 1.00L of a 1.3 molar (1.3 M) solution? ------------------ I am not sure how to start this question, my teacher wants us to use conversion factors and write it out but I don't get how I am supposed to start it.
Monday, March 2, 2015 by Anonymous

Chemistry
What concentration of of CN- is needed to produce the same POH as 3.5*10^-5M solution of BA(OH)2?
Monday, March 2, 2015 by Molly

Chemistry
What volume (mL) of .20 M HCL needs to be added to 1.23 L of .10 M acetic acid to reduce percent ionization to 1.00%?
Monday, March 2, 2015 by Molly

Chemistry
What concentration of of CN- is needed to produce the same POH as 3.5*10^-5M solution of BA(OH)2?
Monday, March 2, 2015 by Molly

Chemistry
What is the mass of a cube of aluminum that is 4.0 cm on each edge? The density of aluminum is 2.7 g/cm3.
Monday, March 2, 2015 by Ciaria

Chemistry
Consider two non-interacting Fermions (half-integer spin) confined in a “box” of length L. Construct the antisymmetric wave functions and compare the corresponding groundstate energies of two systems; one with particles of identical spin and the other with particles ...
Monday, March 2, 2015 by lolo

Chemistry
Calculate the mass of water produced when 3.09g of butane reacts with excess oxygen. 2C4H10 + 13O2-->10H2O + 8CO2 Help.
Monday, March 2, 2015 by Jennie

Chemistry
Why a model of the atom is crucial to understanding chemistry and in explaining the behavior of matter?
Monday, March 2, 2015 by Ciaria

chemistry
I need to know how to figure this out, step by step... Don't assume I know anything.. Break it down for me like I'm a 5 year old... I'm really horrible at figuring out where to even begin... what steps to use.. etc.. Thank you!! CO2(g)+4H2(g)→CH4(g)+2H2O(g) ...
Monday, March 2, 2015 by Jennie

chemistry
Find the molar masses of the following compounds: 1. LiI 2. PbCO4 3. Mg(OH)2 4. (NH4)3PO4 Find the percent composition (percent by mass) of the given element in the following compounds: 1. Fluorine in AgF 2. Hydrogen in glucose (C6H12O6) 3. Oxygen in Fe2(SO4)3 PART II: ...
Monday, March 2, 2015 by Alex

chemistry
1. Many types of spectrophotometers produce graphs containing a base line with peaks. How are the peaks seen on the graphs produced by a spectrometer used in identifying substances? 2. If the analysis of a substance by using spectroscopy shows characteristic peaks, how does ...
Monday, March 2, 2015 by Morgan

chemistry
How many grams of carbon are in 2.42 moles of C2H6
Monday, March 2, 2015 by Anonymous

Chemistry
What is the magnitude of the orbital velocity of the earth when the radius of the earth's orbit around the sun is 150000000?
Sunday, March 1, 2015 by Flora

chemistry
You have 14.0mL of a 0.12M NaOH solution. How many moles of HCl will it take to neutralize this solution?
Sunday, March 1, 2015 by Savannah

Chemistry
Answer these questions about NaCl also known as table salt: 1. What is the name of the compound? 2.Are there any other names that it is known by? If yes, then please list them. 3.What is the chemical formula of the compound? Is it an ionic or covalent molecule? 4. How is it ...
Sunday, March 1, 2015 by Rea

Chemistry
The rate constant for the decomposition of gaseous azomethane, C2 H6 N2 (g) > N2 (g) + C2 H6 (g) Is 40.8 min-1 at 425OC. Find the number of moles azomethane and the number of moles of nitrogen 0.0500 minutes after 2.00 g of azomethane is introduced. Assume that the ...
Sunday, March 1, 2015 by Mahnoor

Chemistry Need Help
How many grams of baking soda, NaHCO3, are needed to react with 125 mL of stomach acid having an HCl concentration of 0.05984 M? The reaction is NaHCO3(aq) + HCl(aq) → NaCl(aq) + CO2(g) + H2O(l). Do I need to chenage mL to L first? I'm really stuck with this question...
Sunday, March 1, 2015 by christine

Chemistry
Calculate the heat of reaction (ΔHrxn) for the following reactions, using heats of formation (ΔHf). Show your work. Refer to a table of heats of formation in your textbook as needed. 5O2(g) + 4NH3(g) → 6H2O(g) + 4NO(g)
Sunday, March 1, 2015 by Morgan

chemistry
To interpret and compare heats of reaction (Hrxn), standard states must be used. What are the standard states for a gas, an aqueous solution, and a pure substance? Why are they important?
Sunday, March 1, 2015 by Morgan

chemistry
1. Outline how you would use a calorimeter to determine the enthalpy of fusion of ice. 2. Suppose the enthalpy of fusion of ice determined from your experiment is lower than the accepted value. List three possible causes of the difference in value. Explain how each cause ...
Sunday, March 1, 2015 by Morgan

chemistry
The equilibrium concentration of NOCl = {0.0610}, NO = [0.0151, and Cl= [0.0142, what is the value of the equilibrium constant? Don't really get how to figure this out..anyone know? Thanks!!
Sunday, March 1, 2015 by S

Chemistry
You have 23.0g of water initially at -46°C. How much energy in joules is required to heat the ice to 0°C? c ice = 2.1 J/g°C. I thought joules was calculated by grams*change in temperature*specific heat. The answer I get from 23*46*2.1 is 2221.8, but web assign says...
Sunday, March 1, 2015 by Harrison

Chemistry
How much milk at 10.00°C needs to be added to a small 150.0 ml cup of coffee at 95.00 °C to drop the temperature to 90.00°C? Assume coffee and milk have the same specific heat capacity as water: 4.186 J/g °C or 1 cal/ g °C, and they also have the same ...
Sunday, March 1, 2015 by Phil

chemistry
The standard enthalpy of formation at 298k for ccl4,h2o,co2,hcl are -22.5,-57.8,-94.1 and-22.1 kcal/mol.calculate ▲rH FOR reaction ccl4+2h2o→co2+HCL
Sunday, March 1, 2015 by rakesh dhakal

Chemistry
When 50.00 mL of an acid with a concentration of 0.214 M (for which pKa = 4.87) is titrated with 0.100 M NaOH, what is the pH at the equivalence point?
Sunday, March 1, 2015 by Anonymous

Chemistry
Use your balanced equation to calculate the volume of 0.12 M Na3PO4 to stoichiometrically react with the 3.0 mL of Co (NO3)2. Show your work.
Sunday, March 1, 2015 by Chem

chemistry
Given the following balanced chemical equation, if 15.4 g AgNO3 are reacted, how many moles of AgCl are produced? 2 AgNO3 + BaCl2 → 2 AgCl + Ba(NO3)2
Sunday, March 1, 2015 by anna

Chemistry combined gas law
Can someone tell me if I did this combined gas law problem correctly? What would happen to the volume of a container whose initial volume is 21.5 L at STP (standard pressure) and is introduced to conditions of 93.2 kPa and 333 K? Formula: P1 x V1 / T1 = P2 x V2 / T2 V2 = P1 x ...
Sunday, March 1, 2015 by Theresa Kwnt

chemistry
CH4+2O2----------CO2+2h2O Use this balanced equation to calculate the mass of water formed when 32g of methane burns
Sunday, March 1, 2015 by Victoria

Chemistry
Question 2: Use your balanced equation to calculate the volume of 0.12 M Na3PO4 to stoichiometrically react with the 3.0 mL of Co (NO3)2. Show your work. 3) Discuss how your supernatant color in the 6 different test tubes supports your calculated result in #2. For example, if ...
Sunday, March 1, 2015 by Question

Chemistry
Procedure 0) The sodium phosphate, Na3PO4 solution has NPFA ratings of 1 (out of 4) for health, 0 for fire, and 0 for reactivity. Cobalt (II) nitrate has 2 for health, 0 fire, and 0 for reactivity. 1) Carefully label (1-­‐6) and weigh 6 small test tubes. 2) You will ...
Sunday, March 1, 2015 by Chem

Chemistry
A standard KHP solution is made by dissolving 2.12 grams of KHP in 100.00 mL of water. The KHP solution is then titrated with NaOH solution. It takes 23.12 mL of NaOH to reach the endpoint. What is the concentration of the NaOH?
Sunday, March 1, 2015 by Anonymous

Quick chemistry help
Please help with these two problems! 1. 566g of C12H22O11=______ C atoms 2. 12 molecules chlorine gas= ________ atoms of Cl
Sunday, March 1, 2015 by Anonymous

Chemistry combined gas law
Can someone tell me if I did this combined gas law problem correctly? What would happen to the volume of a container whose initial volume is 21.5 L at STP (standard pressure) and is introduced to conditions of 93.2 kPa and 333 K? Formula: P1 x V1 / T1 = P2 x V2 / T2 V2 = P1 x ...
Sunday, March 1, 2015 by Theresa Kwnt

Chemistry
If I have 50.0 mL of HA at a concentration of 1.20M and 50.0 mL of NH4OH at a concentration of 0.92M, how many moles of the limiting reactant are there? I guess I should start with a balanced equation, but I have no idea where to start..
Sunday, March 1, 2015 by Sara

chemistry
What volume of ammonia gas at STP is required to neutralize 40 cubic centimetres of 2 Molar sulphuric acid?
Sunday, March 1, 2015 by Czar

Organic Chemistry
How to find the crude percent, percent recovery, and percent composition of benzoic acid and acetanilide if 2 grams of a mixture of benzoic acid and acetanilide was separated through separatory funnel and recrystallize and purified, but only 0.7g of benzoic acid was used to be...
Sunday, March 1, 2015 by Siannah

CHemistry
What is the pH of the resulting solution when 0.20 mole of NaF and 0.05 mole HCl are added to 100 mL water? The Ka for HF is 3.95x10^-4M
Sunday, March 1, 2015 by Mike

chemistry
What is the ph of 0.25 M tartaric acid? Ka=2.5*10^-5M
Sunday, March 1, 2015 by brad

Chemistry
Discuss how your supernatant color in the 6 different test tubes supports your calculated result in #2. For example, if you used less than the volume of sodium phosphate calculated in #2, what would be the limiting reactant and does the observed supernatant color support this.
Sunday, March 1, 2015 by Chem

Chemistry
A 45.4 grams of a gold metal sample was heated with the amount of energy of 228 J. Which of the following would the most plausible temperature change of the gold sample? The specific heat of gold is 0.131 J/g.oC. 12.8 oC to 38.3 oC 24.4 oC to 81.6 oC 23.8 oC to 62.1 oC 38.3 oC...
Saturday, February 28, 2015 by Heather

chemistry
One of the ways to produce iron is to take iron(II) oxide and react it with carbon monoxide to get pure iron and carbon dioxide. The reaction is FeO(s) + CO(g) = Fe(s) + CO2(g). What is the partial pressure of CO2(g) if 2.00 atm of CO and excess iron(II) oxide are used to ...
Saturday, February 28, 2015 by danny

Chemistry
What is the uncertainty (+/- ?) of molar concentration (M)?
Saturday, February 28, 2015 by Anonymous

chemistry
Lead iodide is a relatively insoluble compound. It can dissolve from the solid phase into the aqueous phase with a Keq of 0.00027. If the concentration of lead iodide in the aqueous phase 0.125 M, then: a. we need more information to determine the progress of the reaction. b. ...
Saturday, February 28, 2015 by danny

chemistry
Equilibrium is: a dynamic condition in which the concentration of the reactants is equal to the concentration of the products. a static condition in which the concentration of the reactants is equal to the concentration of the products. a static condition in which the rate of ...
Saturday, February 28, 2015 by danny

chemistry
Hi Please ... is the absolute temperature equal temperature in kelvin? Thanks for you
Saturday, February 28, 2015 by doa'a

Chemistry
Acetone is one of the most important solvents in organic chemistry, used to dissolve everything from fats and waxes to airplane glue and nail polish. At high temperature, it decomposes in a first order process to methane and ketene (CH2=C=O).At 600C, the rate constant is 8....
Saturday, February 28, 2015 by Munavvar

Chemistry
Even when a mechanism is consistent with the rate law , later experimentation may it to be incorrect or only one of several alternative. As an example, the reaction between hydrogen and iodine has the following rate law: rate=k[H]^3[I]2. The long accepted mechanism proposed a ...
Saturday, February 28, 2015 by Munavvar

Chemistry
At body temperature (37C), K of an enzyme-catalyzed reaction is 2.3x10^14 times greater than k of the uncatalyzed reaction. Assuming that the frequency factor A is the same for both reaction, by how much does the enzyme the E^a?
Saturday, February 28, 2015 by Munavvar

Chemistry
A principle of green chemistry is that the energy requirement of industrial processes should have minimal environmental impact. How can the use of catalysts lead to "greener" technology?
Saturday, February 28, 2015 by Munavvar

Chemistry
Need Help! 1. Ammonia is produced by the reaction of hydrogen and nitrogen. N2(g)+3H2(g)→2NH3(g)ammonia How many moles of N2 reacted if 0.65mole NH3 is produced? How many moles of NH3 are produced when 1.2moles H2 reacts? 2.In the acetylene torch, acetylene gas (C2H2) ...
Saturday, February 28, 2015 by Jennie

Chemistry
Define the-half of a reaction. Explain on the molecular level why the half- life of a first-order reaction is constant
Saturday, February 28, 2015 by Munavvar

Chemistry
If the temperature in problem 16.60 (25C), by what factor does the fraction of collisions with energy equal to or greater that the activation energy change?
Saturday, February 28, 2015 by Munavvar

Chemistry
Define the-half of a reaction. Explain on the molecular level why the half- life of a first-order reaction is constant
Saturday, February 28, 2015 by Munavvar

Chemistry
For the reaction 4A (g)+3B (g)=C(g) the following data were obtained at constant temperature: Experiment- 1. Initial (A) (mole/L) 0.0500, 01000, 01000 , 0.0500 2. Initial (B) (mole/L) 0.0500, 0.0500, 0.1000, 0.0500 3. Initial (C)(mole/L) 0.0100, 0.0100, 0.0100, 0.0200 Initial ...
Saturday, February 28, 2015 by Munavvar

Chemistry
You are staying the reaction A2 (g)+B2 (g)=2AB (g) To determine its rate law .Assuming that you have a valid experimental procedure for obtaining (A2)& (B2) at various times, explain how you determine (a)the initial, (b) the reaction order, & (c) the rate constant?
Saturday, February 28, 2015 by Munavvar

Chemistry
Consider the uni molecular reaction cyclopropane? Propylene. The value of log A for high pressure limit is 15.17. Calculate the value of S? For the reaction. Calculate the contribution of S trans in the above reaction at 298K?
Saturday, February 28, 2015 by Munavvar

Chemistry
The magnetic moment (mu) values for Cs2 (MnCl4), k4 (Mn (CN) 6) and K2 (Ni (CN) 4) are 5.9 , 1.8 and 0 B.M, respectively. Explain the difference of these values based on the Valence bond theory.?
Saturday, February 28, 2015 by Munavvar

Chemistry
Vapour pressure of ideal solutions at 25c the vapour pressure of chloroform and carbon tetrachloride are 26.54 and 15.27 kpa respectively. If the liquids from ideal solutions. (A) what is the composition of the vapour in equilibrium with with a solution containing 1mol of each...
Saturday, February 28, 2015 by Munavvar

Chemistry
how many moles of solid mg(oh)2 should you ad to 200 ml of .15M acetic acid solution to produce ph 4.0 buffer?
Saturday, February 28, 2015 by Munavvar

Chemistry Help
How many moles of H2 and N2 can be formed by the decomposition of 0.250 mol of ammonia, NH3? Is it 0.250*3mol H2=0.75 0.25*1mol N2=0.25 Am I correct?
Saturday, February 28, 2015 by Matthew

chemistry
50.0 mL of a solution of HCl is combined with 100.0 mL of 1.15 M NaOH in a calorimeter. The reaction mixture is initially at 22.4°C and the final temperature after reaction is 31.2°C. What is the molarity of the HCl solution? You may assume that there is an excess of ...
Saturday, February 28, 2015 by Marcus

chemistry 2
For the simple decomposition reaction below, rate = k[AB]2 and k = 0.30 L/mols. AB(g) A(g) + B(g) If the initial concentration of AB is 1.20 M, what is [AB] after 10.0 s?
Saturday, February 28, 2015 by Anonymous

Chemistry
Phosphorous acid, H3PO3, is actually a diprotic acid for which Ka1 = 5.0 × 10-2 and Ka2 = 2.0 × 10-7. What are the values of [H+] and [H2PO3-] in a 2.0 M solution of H3PO3?
Friday, February 27, 2015 by Jen

Chemistry
Calculate the pH of a 0.033 M solution of sodium ascorbate, Na2C6H6O6. For ascorbic acid, H2C6H6O6, Ka1 = 7.9 × 10-5 and Ka2 = 1.6 × 10-12. Kb = 1E-14 / 7.9E-5 = 1.266E-10 I 0.033 0 0 C -x +x +x E 0.033-x x x x^2/-0.033 = 1.266E-10 x = 2.044E-6 pOH= -log(2.044E-6...
Friday, February 27, 2015 by Is my answer right?

Chemistry
I'm having a brain malfunction... how to calculate how many grams are in a mole of something? How many grams are in 3.80mol of sodium chloride (NaCl)?
Friday, February 27, 2015 by Jennie

Chemistry
A reaction proceeds with ∆ H = 40 kJ/mol. The energy of activation of the uncatalyzed reaction is 120 kJ/mol, whereas i t is 55 kJ/mol for the catalyzed reaction. How many times faster is the catalyzed reaction than the uncatalyzed reaction at 25°C?
Friday, February 27, 2015 by Jessica

Chemistry Help
How many milliliters of 0.534 M Ba(OH)2 solution are needed to completely neutralize 34.5 mL of 0.220 M HBr solution? The reaction is Ba(OH)2(aq) + 2HBr(aq) → BaBr2(aq) + 2H2O(l) I did 0.0345 * 0.220 = 0.00759 Moles of HCl =2*0.00759= 0.01518 0.01518*1000= 15.18 mL ...
Friday, February 27, 2015 by Matthew

Chemistry
Calculate the hydrogen ion concentration, [H+], in 0.00988 M Ba(OH)2. Careful!
Friday, February 27, 2015 by JUNDY

Chemistry
The autodissociation of water to H+ and OH- is endothermic. At a higher temperature more of the water molecules have sufficient energy to dissociate. So, Kw is greater. At 25oC, Kw = 1.0 x 10-14. (standard Kw) At 65oC, Kw = 1.0 x 10-13. Calculate the hydrogen ion concentration...
Friday, February 27, 2015 by JUNDY

Chemistry
Ammonia is produced by the reaction of hydrogen and nitrogen. N2(g)+3H2(g)→2NH3(g)ammonia How many moles of N2 reacted if 0.65mole NH3 is produced? How many moles of NH3 are produced when 1.2moles H2 reacts?
Friday, February 27, 2015 by Jennie

Chemistry
Ok, I know how to balance chemical equations, however, I don't know how to tell if it is a S, L, aq, or g? How am I supposed to know this?? Mg(s)+AgNO3(aq)→Mg(NO3)2(aq)+Ag(s)​ Express your answer as a chemical equation. Identify all of the phases in your answer...
Friday, February 27, 2015 by Jennie

Chemistry
Dr. Bob222, Calculate the moles of C2H6 in 8.60×1023 molecules of C2H6. I did what you said, I got 8.60*10^23*(1mole/6.02*10^23) = 1.43*10^46??? This is not the answer.. am I doing something wrong?
Friday, February 27, 2015 by Jennie

Chemistry
UMM.. I keep coming up with the wrong answer? How do I calculate this? 1. Calculate the number of Li atoms in 9.9 moles of Li. Express your answer using two significant figures. 2. Calculate the number of CO2 molecules in 3.13×10−2 mole of CO2. 3.Calculate the ...
Friday, February 27, 2015 by Jennie

chemistry
how do i plot the gibbs isotherm equation in excel given concentration and surface tension? I'm looking for surface excess which is the slope on the graph, the equation is r=1/RT(dST/dln(c)), ST is the surface tension. Do I plot the ln of the concentration versus the ...
Friday, February 27, 2015 by marnie

Chemistry
Determine the percent ionization of a 2.45 M solution of benzoic acid
Friday, February 27, 2015 by Gabby

Chemistry
Using a 0.20 M phosphate buffer with a pH of 6.7, you add 0.71 mL of 0.55 M HCl to 52 mL of the buffer. What is the new pH of the solution?
Friday, February 27, 2015 by Ashlee

Chemistry
You are instructed to create 200. mL of a 0.27 M phosphate buffer with a pH of 7.8. You have phosphoric acid and the sodium salts NaH2PO4, Na2HPO4, and Na3PO4 available. (Enter all numerical answers to three significant figures.) H3PO4(s) + H2O(l) equilibrium reaction arrow ...
Friday, February 27, 2015 by Ashlee

chemistry
For the reaction: 2SO2(g) + O2(g) = 2SO3(g) conducted at 25°C and 1 atm. Calculate H°, S°, G°
Friday, February 27, 2015 by P

Chemistry
True of False, Amorphous solids have crystal structures.
Friday, February 27, 2015 by Tony

Chemistry Need Help
Given the chemical equation, Cl2 + F2 2ClF, how many moles of ClF are produced in the reaction, if 1.50 moles Cl2 are made to react with 1.75 moles F2 ? I got the answer 3.50 moles but it was wrong. Can anyone help me please.
Friday, February 27, 2015 by Matthew

Chemistry
Propanoic acid that, along with its sodium salt, can be used to make a buffer that has a pH of 5.25. If you have 532.9 mL of a 0.250 M solution of that acid, how many grams of the corresponding sodium salt do you have to dissolve to obtain the desired pH?
Friday, February 27, 2015 by Dinna

Chemistry Help
The theoretical yield of Cl2 that could be prepared by mixing 15.0 g of manganese dioxide (MnO2) with 30.0 g of HCl is 12.2 g. The limiting reagent was MnO2. When the reaction was run only 8.82 g of Cl2 was collected. The percent yield of Cl2 is_? a)58.8 % b)72.3 % c)29.4 % d)...
Friday, February 27, 2015 by Alex

Chemistry
When 0.500 moles of boron trichloride react with 1.20 moles hydrogen gas to produce elemental boron and hydrogen chloride gas, the actual yield of boron was 66.4 % of the theoretical yield. The mass of boron obtained was _____ g. Please help I'm stuck on it.
Friday, February 27, 2015 by Matt

chemistry
Consider a sample of a hydrocarbon (a compound consisting of only carbon and hydrogen) at 0.959 atm and 298 K. Upon combusting the entire sample in oxygen, you collect a mixture of gaseous carbon dioxide and water vapor at 0.755 atm and 375 K. This mixture has a density of 0....
Friday, February 27, 2015 by Jaxx

chemistry
You made 100.0 mL of a lead(II) nitrate solution for lab but forgot to cap it. The next lab session you noticed that there was only 84.8 mL left (the rest had evaporated). In addition, you forgot the initial concentration of the solution. You decide to take 2.00 mL of the ...
Thursday, February 26, 2015 by JA

chemistry
The rate of removal of Aspirin from the body is a first order reaction with a rate constant,k = 0.34/h How long does it takes for 87.5% of Aspirin to be removed from the body?
Thursday, February 26, 2015 by Mika

chemistry
Sodium nitrate reacts with copper (II) hydroxide. I know how to write it down: NaNo3+CuOH2----> NO REACTION The problem is that I don't understand why it's no reaction I know it's double replacement and we have to look at activity series of metal to figure out ...
Thursday, February 26, 2015 by sakura

Chemistry help
2. How would it be affective if there were a lot of saliva left in the gum after chewing?
Thursday, February 26, 2015 by Anonymous

Chemistry, HELP!
Molybdenum (Mo) is a heavy metal that can have severe health effects on humans and animals. Tailings from a mining operation in Colorado have polluted surface waters used by grazing animals with Mo. Based on the following information determine the concentration of the three Mo...
Thursday, February 26, 2015 by Ethan

Quick chemistry help
How would I find the number of atoms in this mole statement? 12 molecules chlorine gas=_______ atoms of Cl
Thursday, February 26, 2015 by Anonymous

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