Stoichiometry Problems

What conversion factor do you always use in stoichiometry problems?

• reciprocal of the molar mass of a substance

• molar mass of a substance

• mole ratio

• molar volume of a gas

What is the mole ratio of the hydrogen to oxygen in the Synthesis reaction: hydrogen reacts with oxygen to give you H₂O?

• 1:1

• 1:2

• 2:1

• 2:2

Tags

NGSS.HS-PS1-7

When balancing, what part of a chemical equation are you potentially changing?

• coefficients in front of chemical formulas

• chemical formulas derived from the element boxes

• subscripts within the chemical formulas

• the ions (oxidation states) of polyatomic ions

Tags

NGSS.HS-PS1-7

What is the mole ratio of Aluminum to Oxygen in the chemical reaction:

Al + O₂ --> Al₂O₃

• 1:1

• 2:3

• 4:2

• 4:3

• 3: 4

Tags

NGSS.HS-PS1-7

When you balance a chemical equation, you are following:

• the Law of Conservation of Mass

• the Law of Conservation of Energy

• the Law of Motion

• atomic theory

• Coulomb's Law of Attraction

Tags

NGSS.HS-PS1-7

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

• 6

• 2

• 3

• 1

Tags

NGSS.MS-PS1-5

Cl₂ + 2KBr → Br₂ + 2KCl
How many grams of potassium chloride (KCl) can be produced from 356 g of potassium bromide (KBr)?

• 749 g

• 223 g

• 479 g

• 814 g

Tags

NGSS.HS-PS1-7

What is the first thing you must do to solve a stoichiometry problem?

• Write a Balanced Equation

• Panic

• Write an Unbalanced Equation

• Avogadro's Number

The ____ in a balanced chemical reactions gives the MOLE RATIO used in stoichiometry problems.

• coefficients

• reactants

• subscripts

• products

B₂H₆ + 3O₂ -->2 HBO₂ + 2 H₂O
 What mass of O₂ will be needed to burn 36.1 g of B₂H₆?

• 13.8 g O₂

• 3.86 mol of O₂

• 125.2 g O₂

Tags

NGSS.HS-PS1-7