Question

Select the correct mass for each of the samples described below.

Answer 1

To determine the mass of each compound, we need to convert them into units of moles first. We use avogadros number to do this and use the molar mass of the compounds to convert to mass.

3.01 × 1023 molecules H2O ( 1 mole / 6.022x10^23 kg) (18.02 g / 1 mole) = 9.01 g

8.32 × 1020 formula units CaBr2 ( 1 mole / 6.022x10^23 kg) (199.89 g / 1 mole) = 0.28 g

1.93 × 1026 molecules XeF6 ( 1 mole / 6.022x10^23 kg) (245.28 g / 1 mole) = 78610.16 g

Answer 2

Select the correct mass for each of the samples described below.

3.01 × 1023 molecules H2O----9.01

8.32 × 1020 formula units CaBr2 -----0.276

1.93 × 1026 molecules XeF6 -----78.600