Answer:
a) <u>0.168 moles O2</u>
<u>b) </u> <u>9.50 grams O2</u>
<u>c) 0.01662 kg NO</u>
<u>d)</u>88.9 %
Explanation:
Step 1: Data given
Molar mass of NH3 = 17.03 g/mol
Molar mass of O2 = 32 g/mol
Molar mass of NO = 30.01 g/mol
Molar mass of H2O = 18.02 g/mol
Step 2: The balanced equation:
4NH3 + 5O2 → 4NO + 6H2O
a. How many moles of ammonia will react with 6.73g of oxygen?
Calculate moles of oxygen = mass O2/ molar mass O2
moles oxygen = 6.73 grams / 32.00 g/mol = 0.210 moles
Calculate moles of NH3
For 4 moles of NH3 we need 5 moles O2 to produce 4 moles NO and 6 moles H2O
For 0.210 moles O2 we need 4/5 *0.210 = <u>0.168 moles O2</u>
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b. If 6.42g of water is produced, how many grams of oxygen gas reacted?
Calculate moles of H2O = 6.42 grams / 18.02 g/mol = 0.356 moles
Calculate moles of O2:
For 4 moles of NH3 we need 5 moles O2 to produce 4 moles NO and 6 moles H2O
For 0.356 moles H2O we'll need 5/6 * 0.356 = 0.297 moles O2
Calculate mass of O2 = moles O2 * molar mass O2
Mass O2 = 0.297 moles O2 * 32.00 g/mol = <u>9.50 grams O2</u>
c. If the reaction uses up 9.43105 g of ammonia, how many kilograms of nitrogen monoxide will be formed?
Calculate moles of ammonia = 9.43105 grams / 17.03 g/mol =0.5538 moles
Calculate moles of NO:
For 4 moles of NH3 we need 5 moles O2 to produce 4 moles NO and 6 moles H2O
For 0.5538 moles of NH3 we'll have 0.5538 moles NO
Calculate mass of NO
Mass NO = 0.5538 moles * 30.01 g/mol = 16.62 grams = <u>0.01662 kg NO</u>
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d. When 2.51 g of ammonia react with 3.76 g of oxygen, 2.27 g of water vapor are produced. What is the percentage yield of water?
<em>Calculate moles of NH3</em> = 2.51 grams / 17.03 g/mol = 0.147 moles
<em>Calculate moles of O2 </em>= 3.76 grams / 32 g/mol = 0.118 moles
<em>Determine the limiting reactant</em>
O2 is the limiting reactant, it will completely be consumed (0.118 moles)
NH3 is in excess. There will react 4/5 * 0.118 = 0.0944 moles
There will remain 0.147 - 0.0944 = 0.0526 moles
<em>Calculate moles H2O</em>: For 0.118 moles O2 we'll have 6/5 * 0.118 = 0.1416 moles H2O
<em>Calculate mass H2O</em> = 0.1416 moles * 18.02 g/mol = 2.552 grams H2O
<em>Calculate % yield</em> = (2.27/2.552)*100 % = <u>88.9 %</u>
