Chemistry

What is the molar mass of H₂O?

• 6.02 x 10²³
• 16 grams
• 18 grams
• 15.99999 grams

What is the molar mass NaCl?

• 58 grams
• 22.95 grams
• 162 grams
• 6.02 x 10²³

Calculate the number of moles of atoms in  4.6 g of sodium.

• 0.1
• 0.2
• 0.3
• 0.4

Calculate the mass of  2 mol of methane. 

• 2
• 8
• 16
• 32

Calculate the number of moles of carbon dioxide contained in 11g of CO_2.

• 0.25
• 0.5
• 11
• 44

Calculate the number of moles copper (II) sulfate in 320g of CuSO_4.

• 2
• 4
• 6
• 8

What would be the mass of 1.5mol H₂O ?

• 20 g

• 27 g

• 32 g

• 40 g

Which expression below show the correct method of determining the percent composition of Sodium in Na₂CO₃?

• %Na = (22.99g/106g) x 100
• %Na = (22.99g/106) / 100
• %Na = (45.98g/106g) x 100
• %Na = (106/45.98g) x 100

What is the percent by mass of oxygen in MgO?

• 20%
• 40%
• 50%
• 60%

How many grams are there in 1.6 moles of CaO? (rounded)

• 35
• 56
• 90
• 0.286