Stoichiometry

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

• 2
• 4
• 6
• 8

Tags

NGSS.HS-PS1-7

2 KClO₃ → 2 KCl + 3 O₂

How many moles of oxygen are produced when 6.7 moles of KClO₃ decompose completely?

• 6.7 mol

• 1.0 mol

• 10.1 mol

• 4.5 mol

2 Na + 2 H₂O → 2 NaOH + 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

Cl₂ + 2 KBr → Br₂ + 2 KCl

How many grams of potassium chloride (KCl) can be produced from 356 g of chlorine and 356 g of potassium bromide (KBr)?

• 749 g

• 223 g

• 479 g

• 814 g

What is an Excess Reactant?

• amount you end with

• what you run out of first

• what you have left over

• what you start with

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

Mg + 2 HCl --> MgCl₂ + H₂

• Mg

• H2

• MgCl2

• HCl

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

What is a Limiting Reactant?

• speeds up a reaction

• what you run out of first

• what you have left over

• slows down a reaction

You need 2 pieces of bread, 1 tablespoon of peanut butter and 2 tablespoons of jelly to make a sandwich.  If you have 10 pieces of bread, 4 tablespoons of peanut butter and 20 tablespoons of jelly, what is the limiting reactant?

• bread
• jelly
• peanut butter
• sandwich

Tags

NGSS.HS-PS1-2

2 Al + 3 H₂SO₄ ---> Al₂(SO₄)₃ + 3 H₂

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