Question

can be recovered from 25.0 g of $ce{fe_{2}o_{3}}$? $\boldsymbol{17.5g}$

1. how much silver can be produced from 125 g of $ce{ag_{2}s}$?

54

Explanation:

Step1: Calculate molar mass of $\text{Ag}_2\text{S}$

Molar mass of $\text{Ag} = 107.87\ \text{g/mol}$, molar mass of $\text{S} = 32.07\ \text{g/mol}$
$$\text{Molar mass of }\text{Ag}_2\text{S} = 2\times107.87 + 32.07 = 247.81\ \text{g/mol}$$

Step2: Find moles of $\text{Ag}_2\text{S}$

$$\text{Moles of }\text{Ag}_2\text{S} = \frac{125\ \text{g}}{247.81\ \text{g/mol}} \approx 0.5044\ \text{mol}$$

Step3: Relate moles of $\text{Ag}$ to $\text{Ag}_2\text{S}$

1 mole $\text{Ag}_2\text{S}$ contains 2 moles $\text{Ag}$
$$\text{Moles of }\text{Ag} = 2\times0.5044 = 1.0088\ \text{mol}$$

Step4: Calculate mass of $\text{Ag}$

$$\text{Mass of }\text{Ag} = 1.0088\ \text{mol} \times 107.87\ \text{g/mol} \approx 109\ \text{g}$$

Answer:

109 g