Solution (Self Assessment)

Solution

a).

Molecular mass of H2O2 = 2 (1.008) + 2 (16)

= 2.016 + 32

= 34.016 amu

Mass of 1 mole of CO2 = 34.016 g

Mass of 2.5 moles of CO2 = 34.016 x 2.5 g

= 85.04 g

Mass of H2O2 is 85.04 g

b).

Molecular mass of H2O2 = 2 (1.008) + 2 (16)

= 2.016 + 32

= 34.016 amu

Mass of 1 mole of H2O2 = 34.016 g

Moles of 34.016 g of H2O2 = 1 mole

Moles of 1 g of H2O2 = 1/(34.016 ) mole

Moles of 30 g of H2O = 30 × 1/(34.016 ) mole

= 0.882 moles

So, number of moles of 30 g of H2O2 is 0.882 moles.9

Formula mass of NaCl = 23 + 35.5

= 23 + 35.5

= 58.5 amu

Mass of 1 mole of NaCl = 58.5 g

Moles of 58.5g of NaCl = 1 mole

Moles of 1 g of NaCl = 1/(58.5 ) mole

Moles of 12.5 g of NaCl = 12.5 × 1/(58.5 ) mole

= 0.214 moles

ss1So, number of moles of 12.5 g of NaCl is 0.214 moles.

Molecular mass of BaSO4 = 137 + 32 + 4(16)

= 137 + 32 + 64

= 233 amu

Mass of 1 mole of BaSO4 = 233 g

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