Chemistry Midterm Review Spring

How can you work out a molecule or compounds relative formula mass?

• The sum of the relative atomic masses of the atoms in the numbers shown in the formula

• The sum of the atomic numbers of the atoms in the numbers shown in the formula

What is the relative formula mass of N₂O? A_r of N = 14 and A_r of O = 16.

• 30

• 44

• 46

What is the relative formula mass of Ca(NO₃)₂? A_r of Ca = 40, A_r of N = 14 and Ar of O = 16.

• 70

• 102

• 164

What is the relative formula mass of Ca(NO₃)₂? A_r of Ca = 40, A_r of N = 14 and Ar of O = 16.

• 70

• 102

• 164

What is the number of moles in 23 g of NO₂? (M_r of NO₂ = 46)

• 0.33

• 1

• 0.5

What is the mass of 0.5 mol of HF gas? (M_r of HF = 20)

• 0.025 g

• 10 g

• 40 g

Tags

NGSS.HS-PS1-7

What is equation to calculate mass when given the moles and molar mass (RAM)?

• moles x RAM

• moles ÷ RAM

• RAM ÷ moles

What is equation to calculate moles when given the mass and molar mass (RAM)?

• mass x RAM

• mass ÷ RAM

• RAM ÷ mass

What is the amount of silver atoms in 216 g of silver, Ag? (A_r of Ag = 108)

• 2 mol

• 0.5 mol

• 4 mol

What amount of O₂ reacts with 4 mol of Al?

4Al + 3O₂ → 2Al₂O₃

• 3 mol

• 2 mol

• 4 mol

Tags

NGSS.HS-PS1-7