Stoichiometry and Limiting Reactants Long Answer

A propane grill on a backyard patio is left burning for too long and eventually goes out. Which of the following chemicals is the limiting reagent?

• oxygen gas

• propane

• carbon dioxide

• water vapor

Tetraphosphorus decoxide combines with water to form phosphoric acid in the following unbalanced chemical equation:

P₄O₁₀ + H₂O → H₃PO₄

In order to form 100.0 g phosphoric acid, how much tetraphosphorus decoxide will you need?

• 289.7 g

• 138.1 g

• 262.6 g

• 72.42 g

Tags

NGSS.HS-PS1-7

Mercury (I) carbonate will break down when exposed to heat:

Hg₂CO₃ → Hg₂O + CO₂

How much Hg₂O will be formed when 2.50 g of Hg₂CO₃ is decomposed?

• 1.17 g

• 2.26 g

• 0.0977 g

• 4.00 g

Tags

NGSS.HS-PS1-7

The following chemical equation represents a reaction that we will do in the lab next quarter:

Mg (s) + 2 HCl (aq) → MgCl₂ (aq) + H₂ (aq)

How many grams of excess reagent will be left over when 6.00 g of HCl reacts with 5.00 g of Mg?

(hint: determine the limiting reagent first )

• 4 g

• 1 g

• 2 g

• 3 g

Tags

NGSS.HS-PS1-7

Balance the following reaction :
 
CaC₂(s)   +   H₂O(l)   -->   C₂H₂(g)   +   Ca(OH)₂(aq)

• 1,2,2,2
• 1,2,1,1
• 2,1,1,1
• 2,1,2,1

Tags

NGSS.HS-PS1-7

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

Tags

NGSS.HS-PS1-7

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

Tags

NGSS.HS-PS1-7

A student burns 1.50 mol C₃H₈ according to the following reaction:

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

How many grams of carbon dioxide are produced?

• 44.0 g

• 66.1 g

• 132 g

• 198 g

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-7

2H₂ + O₂ → 2H₂O

How many moles of water can be produced if 8 moles H₂ are used?

• 4 moles

• 8 moles

• 16 moles

• 2 moles

Tags

NGSS.HS-PS1-7

The limiting reactant

• slows the reaction down
• is used up first
• is the reactant that is left over
• controls the speed of the reaction