Question

What is the mass of gold in a sample of 100 g of 24-carat gold?

Answer 1

Step 1:

Gold is a noble metal. It is a soft and yellow metal. It is the most malleable and ductile metal. The quantity of gold in an alloy is called its gold content. The gold content of an alloy is expressed either in carats or as a mass per cent.

Step 2:

A carat of gold is equal to 24 mass units of the metal. Therefore, 24 carat represents pure gold.

The weight of the sample is 100g.

Step 3:

Since 24-carat gold represents 100% pure gold. So, 1-carat gold has a purity of $\frac{100}{24}$ pure gold.

The mass percent of gold in 100g is calculated in the following manner:

$\begin{array}{rcl}\mathrm{Mass}\mathrm{percent}\mathrm{of}\mathrm{gold}\mathrm{in}100\mathrm{g}\mathrm{of}24\mathrm{carat}\mathrm{gold}& =& \frac{100}{24}\times 100\\ & =& 416.67\end{array}$

Therefore, the mass of gold in a sample of 100 g of 24-carat gold will be 416.67.