More AP CHEM HELP!!!!

Question

When ammonia gas, oxygen gas and methane gas(CH4) are combined, the products are hydrogen cyanide gas and water.

a) balance equation

b) calculate mass of each product produced when 225 g of O2 is reacted with an excess of the other two reactants.

c) if the actual yeild of the experiment in b) is 105 g of HCN, calculate the percent yeild

please explain/show work

Answer 1

2NH3 + 2CH4 + 3O2 => 2HCN + 6H2O

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ratios:

O2 = 3 moles @ 32.0 g/mol = 96.0 grams

HCN = 2 moles @ 27.03 g/mol = 54.06 g/mol

H2O = 6 moles @ 18.015 g/mol = 108.09 grams

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b) calculate mass of each product produced when 225 g of O2 is reacted with an excess of the other two reactants.

225 g O2 @ 54.06 g HCN / 96.0 g O2 = 126.7 grams of HCN

your answer (3 sigfigs) : 127 g HCN

225 g O2 @ 108.09 g H2O / 96.0 g O2 = 253.3 grams H2O

Your answer is (3 sigfigs): 253 g H2O

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c) if the actual yeild of the experiment in b) is 105 g of HCN, calculate the percent yeild

105 g yield/ 127 g expected (100) = 82.68 % yield

Your answer(3sigfigs) : 82.7% yield