Stoichiometry Lesson

Stoichiometry Lesson

Multiple Choice

What is the mass of 54.3x10⁴⁵molecules of BeO?

• 3.27x10⁷⁰ g

• 9.01 x10²²g

• 2.25 x10²⁴ g

• 1.31 x10⁶⁹g

Multiple Choice

What is the molar mass of Mg₃N₂?

• 191.6 g/mol

• 76.64 g/mol

• 38.32 g/mol

• 100.95 g/mol

Multiple Choice

How many moles are in 4.5x10²⁴ particles?

• 0.747 particles

• 0.747 mol

• 2.71x10⁴⁷ mol

• 2.71x10⁴⁷ particles

Multiple Choice

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

Multiple Choice

2Na + 2H₂O → 2NaOH+ H₂
How many grams of hydrogen are produced if 120 g of Na are available?

• 5.2 g
• 2.6 g
• 690 g
• 45 g

Multiple Choice

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

Multiple Choice

2H₂ + O₂ → 2H₂O

How many moles of oxygen are consumed if 8 moles H₂ are used?

• 2

• 4

• 6

• 8

Multiple Choice

Identify the limiting reagent when 6.00 g HCl combines with 5.00 g Mg to form MgCl₂.

Mg + 2HCl --> MgCl₂ + H₂

• Mg

• H2

• MgCl2

• HCl

Multiple Choice

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

Multiple Choice

11.

LiOH + KCl → LiCl + KOH

b) I actually produced 6 grams of lithium chloride and I began this reaction with 20 grams of lithium hydroxide. What is my percent yield?

• 16.9%

• 5.91%

• 1.88%

• 12.3%

Multiple Choice

9. Complete the equation for the percent yield of a chemical reaction:

Percent yield=(________)÷(________)×100%

• actual yield; theoretical yield

• theoretical yield; actual yield