19 Gold reacts with the elements in Group 7 of the periodic table.
0.175 g of gold reacts with chlorine.
The equation for the reaction is:
2 Au + 3 Cl2 - 2 AuCla
Calculate the mass of chlorine needed to react with 0.175 g of gold.
Give your answer in mg
Relative atomic masses (Ar): Cl = 35.5 Au = 197

The mass of chlorine gas required is 94.6 mg

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

......(1)

Given mass of gold = 0.175 g

Molar mass of gold = 197 g/mol

Plugging values in equation 1:

The given chemical equation follows:

By the stoichiometry of the reaction:

If 2 moles of gold reacts with 3 moles of chlorine gas

So, 0.000888 moles of gold will react with = of chlorine gas

Molar mass of chlorine gas = 71 g/mol

Plugging values in equation 1:

      (Conversion factor: 1 g = 1000 mg)

Hence, the mass of chlorine gas required is 94.6 mg

the answer is b. dilution