Stoichiometry

In a lab, a scientist calculate he should produce 12.3 grams of product in his experiment. When he is finished collecting his product it weighs 10.1 grams. What is his percent yield?

• 82%
• 0.82%
• 10.1 %
• 100%

Tags

NGSS.HS-PS1-7

N₂ +  3H₂ → 2NH₃ 
How many moles of hydrogen are needed to react with 2 moles of nitrogen?

• 6
• 2
• 3
• 1

Tags

NGSS.HS-PS1-7

For the Balanced Reaction: 3 Mg + 1 Fe₂O₃ → 3 MgO + 2 Fe; What is the Ratio of moles of MgO to moles Fe?

• 3mol Mg / 2 mol Fe
• 2 mol Mg/ 3 mol Fe
• 1 mol Fe/ 2 mol Fe
• 3 mol MgO / 2 mol Fe

Tags

NGSS.HS-PS1-7

What is the measured amount of a product obtained from a chemical reaction?

• mole ratio
• theoretical yield
• percentage yield
• actual yield

If a chemist calculates the maximum amount of product that could be obtained in a chemical reaction, he or she is calculating the

• theoretical yield
• mole ratio
• actual yield
• percentage yield

Tags

NGSS.HS-PS1-7

Mole ratios are obtained from the

• balanced chemical equation
• periodic table
• molar mass

Tags

NGSS.HS-PS1-7

What is the mole ratio of H₂O to H₃PO₄ in the following chemical equation?   P₄O₁₀ + 6 H₂O --> 4 H₃PO₄ 

• 6:4
• 4:6
• 1:3
• 3:1

Tags

NGSS.HS-PS1-7

When does a chemical reaction stop?

• When the lab is finished
• When the excess reactant is used up
• When the limiting reactant is used up
• Chemical reactions never stop

How many grams are in 7.8 moles of NaCl?

• 476 grams

• 460 grams

• 452 grams

• 462 grams

9. Complete the equation for the percent yield of a chemical reaction:
Percent yield=(________)÷(________)×100%

• actual yield; theoretical yield
• theoretical yield; actual yield

Tags

NGSS.HS-PS1-7