11.1 Defining Stoichiometry

What is the scientific law that states that matter is not created or destroyed but only transformed in a chemical reaction?

• law of conservation of energy

• law of conservation of mass

• law of conservation of momentum

• law of gravity

What do the coefficients in the following balanced chemical equation mean?

2H₂ + O₂ → 2H₂O

• 2 moles of hydrogen and 1 mole of oxygen in the reactants

• 2 moles of oxygen and 1 mole of hydrogen in the reactants

• 2 moles of oxygen and 1 mole of hydrogen in the products

• 2 moles of hydrogen and 1 mole of oxygen in the products

What is the balanced chemical equation for the reaction between hydrochloric acid and calcium carbonate when the products of the reaction are calcium chloride, carbon dioxide, and water?

• HCl + CaCl₂ → CaCO₃ + CO₂ + H₂O

• HCl + CaCO₃ → CaCl₂ + CO₂ + H₂O

• 2HCl + CaCO₃ → CaCl₂ + CO₂ + H₂O

• 2HCl + CaCl₂ → CaCO₃ + CO₂ + 2H₂O

How many grams of Fe₂O₃ are present in 0.82 mol Fe₂O₃?

• 130 g

• 65 g

• 131 g

• 260 g

Balance the following equation with the smallest whole-number coefficients. What is the coefficient for H₂O in this equation?

PBr₃ + H₂O → H₃PO₃ + HBr

• 2

• 3

• 4

• 1

N₂ +  3H₂ → 2NH₃ 
How many moles of hydrogen are needed to react with 5 moles of nitrogen?

• 6
• 2
• 3
• 15

Tags

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

What is the mole ratio in the following reaction:
2CO  +  O₂  → 2CO₂

• 2:1:2
• 1:1:1
• 1:2:1
• Have no clue what a mole ratios is!!

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

Mole ratios are obtained from the

• balanced chemical equation

• periodic table

• molar mass

• chemical formulas