A common talcum powder contains 4% m/m zinc oxide, which acts as an antiseptic. How much zinc oxide is present in 300 g of the talcum powder?
[Pg. No. 76]

Given:

Talcum powder = 300 g

Zinc oxide = 4% m/m

$$\text{Mass of oxide} = \frac{4}{100} \times 300 = 12 \text{ g}$$

Therefore, 12 g of zinc oxide is present in 300 g of talcum powder.