Stoichiometry Review

What can be determined from a balanced chemical equation?

• Mole ratio of any two substances in the reaction
• Energy released in the reaction.
• Electron configuration of all elements in the reaction. 
• Mechanism involved in the reaction. 

Tags

NGSS.HS-PS1-7

Calculate the molar mass of Mg(OH)_2.

• 33.2 g/mol
• 41.3 g/mol
• 86.9 g/mol
• 58.3 g/mol

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

CH₄ + 2 O₂ → CO₂ + 2 H₂O How many moles of carbon dioxide are produced from the combustion of 110 g of CH₄? (Hint: convert grams of CH4 to moles of CH4)

• 13.7 mol

• 2.75 mol

• 6.11 mol

• 6.85 mol

For the Balanced Reaction: 3 Mg + 1 Fe₂O₃ → 3 MgO + 2 Fe; What is the Ratio of moles of MgO to moles Fe?

• 3mol Mg / 2 mol Fe
• 2 mol Mg/ 3 mol Fe
• 1 mol Fe/ 2 mol Fe
• 3 mol MgO / 2 mol Fe

What number should be in front of the NF₃ in this chemical reaction?
___N₂+___F₂ --> ___ NF₃

• 1
• 2
• 3
• 4

Tags

NGSS.HS-PS1-7

Mole ratios are obtained from the

• balanced chemical equation
• periodic table
• molar mass

In every chemical reaction, _____.

• mass and molecules are conserved.
• moles and liters are conserved.
• mass and atoms are conserved.
• moles and molecules are conserved. 

Tags

NGSS.HS-PS1-7

Molar masses are determined from

• a conversion factor.
• any mole ratio in the problem.
• the mole ratio of a given amount of reactant to an unknown amount of product.
• the periodic table. 

Which of the following is an INCORRECT interpretation of the balanced equation shown below?
4KClO₃  --> 3KClO₄  +  KCl

• 4 mol KClO₃ --> 3 mol KClO₄ +  1 mol KCl

• 4 molecules KClO₃ --> 3 molecules KClO₄ + 1 molecule KCl

• 4 g  KClO₃ --> 3 g  KClO₄ + 1 g   KCl

• All of these are correct interpretations

Tags

NGSS.HS-PS1-7