The chemical formula for lithium fluoride is LiF . A chemist determined by measurements that 0.030 moles of lithium fluoride participate in a chemical reaction. Calculate the mass of lithium fluoride that participates. Be sure your answer has the correct number of significant digits.

To calculate the mass of lithium fluoride (LiF) that participates in the reaction, follow these steps: 1. **Determine the Molar Mass of LiF:** - **Lithium (Li):** ≈ 6.94 g/mol - **Fluorine (F):** ≈ 19.00 g/mol - **Total Molar Mass of LiF:** \( 6.94 \, \text{g/mol} + 19.00 \, \text{g/mol} = 25.94 \, \text{g/mol} \) 2. **Calculate the Mass Using the Number of Moles:** \[ \text{Mass} = \text{Moles} \times \text{Molar Mass} = 0.030 \, \text{mol} \times 25.94 \, \text{g/mol} = 0.7782 \, \text{g} \] 3. **Apply Significant Figures:** - The number of moles (0.030) has **two significant digits**. - Therefore, the mass should also be reported with **two significant digits**. - Rounded to two significant figures: **0.78 g** **Answer:** 0.78 g of lithium fluoride participates in the reaction.