Stoichiometry Review

What is the correct setup for the following problem?

How many moles are in 12.4 grams of Helium?

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

If I have grams of a substance and what to know how many moles it is what conversion is needed?

• Divide by Molar Mass

• Multiply by Molar Mass

• Divide by Avogadro's Number

• Multiply by Avogadro's Number

How many grams are in 7.8 moles of NaCl?

• 476 grams

• 460 grams

• 452 grams

• 462 grams

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
• Ask for help

Tags

NGSS.HS-PS1-7

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

Tags

NGSS.HS-PS1-7

In the reaction 2 H₂ + O₂ → 2 H₂O what is the mole ratio of oxygen to water

• 1/2

• 2/1

• 3/4

• 4/3

Tags

NGSS.HS-PS1-7

What is the molar mass of NaOH?

• 40.00 g/mol

• 38.99 g/mol

• 23.99 g/mol

• 57.00 g/mol

2NaClO₃ (s) → 2NaCl (s) + 3O₂ (g)

12.00 moles of NaClO₃ will produce how many grams of O₂?

NaClO₃ = 106.44 g/mol ; O₂ = 32.00 g/mol

• 256 g of O₂

• 576 g of O₂

• 288 g of O₂

• 384 g of O₂

Tags

NGSS.HS-PS1-7

Calculate the molar mass for Al(OH)₃

• 78.0 g/mol

• 72 g/mol

• 28 g/mol

• 25 g/mol