Mixed Stoichiometry Problems

Using the following equation:

Fe₂O₃(s) + 3H₂(g) → 2Fe(s) + 3H₂O(l)

How many moles of Fe can be made from 6 moles H₂? (This is a one step conversion using mole ratio)

• 4 moles Fe

• 6 moles Fe

• 9 moles Fe

• 2 moles Fe

Cl₂ + 2KBr → Br₂ + 2KCl

How many grams of KCl can be produced from 356 g of KBr? (This is a three step conversion from grams to moles, mole ratio, and then moles to grams)

• 749 g

• 223 g

• 479 g

• 814 g

Tags

NGSS.HS-PS1-7

Fe₂O₃ + 3H₂ → 2Fe + 3H₂O

About how many grams of H₂O will be produced from 150 grams of Fe₂O₃? (This is a three step conversion: grams --> moles, mole ratio, then moles --> grams)

• 50 grams H₂O

• 60 grams H₂O

• 5000 grams H₂O

• 6000 grams H₂O

Tags

NGSS.HS-PS1-7

2C₂H₆ + 7O₂ = 4CO₂ + 6H₂O
What mass of CO₂ will be produced from the reaction of 37.5 g C₂H₆?

• 27.5 g
• 12.8 g
• 55 g
• 110 g

The Formula to make S'mores is:
2C + 1M + G₂ → C₂MG₂. If you have 5 Marshmallows (M), 9 Chocolate Pieces (C), and 9 Graham Cracker Halves (G), how many S'mores can you make?

• 5
• 4
• 8
• 42

Tags

NGSS.HS-ETS1-3

2H₂ + O₂ → 2H₂O

How many moles of oxygen are consumed if 0.837 moles H₂ are used?

• 0.4185 mol O₂

• 0.419 mol O₂

• 1.67 mol O₂

• 0.837 mol O₂

Tags

NGSS.HS-PS1-7

Given the equation below, how many grams of AlCl₃ will be produced from 0.2791 moles of chlorine gas?
Al + Cl₂  --> AlCl₃

• 0.1861g AlCl₃
• 24.81g AlCl₃
• 37.22 g AlCl₃
• 55.82 g AlCl₃

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

Tags

NGSS.HS-PS1-7

In the equation 2 Al₂O₃ --> 4 Al + 3 O₂, what is the mole ratio of aluminum to oxygen?

• 10:6 
• 3:4
• 4:3
• 2:3

Tags

NGSS.HS-PS1-7

How many moles of H₂O are produced by 4.8 moles of O₂?
2H₂ +O₂ -----> 2H₂O

• 9.6 mol H₂O
• 317 mol H₂O
• 906 mol H₂O
• 3.7 mol H₂O