Stoichiometry Review

Mole ratios are obtained from the

• balanced chemical equation
• periodic table
• molar mass

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

2Al + 3H₂SO₄ -> Al₂(SO₄)₃ + 3H₂
How many grams of aluminum sulfate would be formed if 250g H₂SO₄ completely reacted with aluminum?

• 0.85 g
• 290 g
• 450 g
• 870 g

For the reaction represented by the equation Cl₂ + 2KBr → Br₂ + 2KCl, how many grams of potassium chloride can be produced from 356 grams potassium bromide?

• 749 g
• 225 g
• 479 g
• 814 g

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

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

Using the following equation:
Fe₂O₃(s) + 3H₂(g) → 2Fe(s) + 3H₂O(l)
How many moles of iron can be made from  6 moles H₂? 

• 4 moles Fe
• 6 moles Fe
• 9 moles Fe
• 2 moles Fe

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

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

Fe (s) + S (l) --> FeS (s)  

In the experiment above, 7.62 g of Fe are allowed to react with 8.67 g of S.
How much FeS is formed?

• 14.8 g
• 12.2 g
• 13.7 g
• 19.9 g

2H₂  +   O₂  →  2H₂O
How many moles of oxygen are consumed if 8 moles H₂ are used?

• 2
• 4
• 6
• 8