Zinc oxide,a useful fungicide,can be prepared from zinc blende ore by roasting the ore in air and then purifying the resulting oxide.What mass of zinc oxide could be obtained from 5.00 kg of a zinc blende ore that analyzed at 48.6% zinc sulfide,if the net conversion is 66.7% efficient?
A)0.98 kg
B)1.35 kg
C)1.51 kg
D)1.89 kg
E)2.07 kg

Question

Quizplus · Accepted Answer

First, calculate the mass of zinc sulfide (ZnS) in the ore: $5.00 \, \text{kg} \times 48.6\% = 2.43 \, \text{kg}$. The reaction for converting zinc sulfide to zinc oxide (ZnO) is: $\text{ZnS} + \frac{3}{2} \text{O}_2 \rightarrow \text{ZnO} + \text{SO}_2$. The molar masses are approximately 97.46 g/mol for ZnS and 81.38 g/mol for ZnO. The theoretical yield of ZnO from 2.43 kg of ZnS is calculated by the ratio of their molar masses: $\frac{2.43 \, \text{kg} \times 1000 \, \text{g/kg}}{97.46 \, \text{g/mol}} \times 81.38 \, \text{g/mol} = 2.03 \, \text{kg}$. Considering the 66.7% efficiency: $2.03 \, \text{kg} \times 66.7\% = 1.35 \, \text{kg}$.

Zinc Oxide,a Useful Fungicide,can Be Prepared from Zinc Blende Ore