Mole calculations

N₂ + 3H₂ → 2NH₃

How many moles of H₂ is needed to react with 2 moles of N₂?

Mathematical Equivalence

ON

The mass of one mole of an element is equal to

• its atomic number from the periodic table, but in amus.

• its atomic mass from the periodic table, but in amus.

• its atomic mass from the periodic table, but in grams.

• its atomic number from the periodic table, but in grams.

Samuel wants to prepare a relaxing bath and decides to add 6.0 moles of epsom salt (MgSO₄) to the water. How many grams of MgSO₄ does he need to add to the bath?

• 3.6 x 10²⁴ g

• 720 g

• 0.050 g

• 340 g

During a winter storm, William, Aiden, and Ava decided to clear the ice from their neighborhood sidewalks. They used 455 g of calcium chloride, CaCl₂, for the task. How many moles of CaCl₂ did they use?

• 50,500 moles

• 4.10 moles

• 7.56 x 10^-22 moles

• 111 moles

One mole of carbon dioxide (CO₂) contains 6.02 x 10²³ _____.

• atoms

• formula units

• ions

• molecules

What is the empirical formula for the following molecular formula: C₆H₁₄

• C₆H₁₄
• C₃H₇
• CH₂
• CH₃

what is the volume of 2 mole of a gas?

• 24dm³

• 48dm³

• 24000cm³

• 48000cm³

What is the percent by mass of sodium in NaCl?

• 39%
• 61%
• 35%
• 65%

9. Complete the equation for the percent yield of a chemical reaction:
Percent yield=(________)÷(________)×100%

• actual yield; theoretical yield
• theoretical yield; actual yield

What is a limiting reactant?

• The reactant that determines how much product can be made

• The reactant that is in excess

• The product that you can make the most of

• The amount of reactants that react with each other