Answer
There is 0.0991 mole of dipyrithione in 25.0 g of that.
Work Step by Step
1. As we have determined in 7.73a, the molar mass for dipyrithione (C_{10}H_8N_2O_2S_2) is equal to 252.3 g/mole. Use this information as a conversion factor.
$ \frac{1 \space mole \space (C_{10}H_8N_2O_2S_2)}{ 252.3 \space g \space (C_{10}H_8N_2O_2S_2)}$ and $ \frac{ 252.3 \space g \space (C_{10}H_8N_2O_2S_2)}{1 \space mole \space (C_{10}H_8N_2O_2S_2)}$
2. Calculate the number of moles $(C_{10}H_8N_2O_2S_2)$
$ 25.0g \times \frac{1 mole}{ 252.3g} = 0.0991 \space moles$
