Which quantity is equivalent to 39 grams of LiF?

• A. 2 moles of LiF
• B. 0.5 mole of LiF
• C. 3 moles of LiF
• D. 1 mole of LiF

Answer: (D)

Verified step by step guidance

1. Identify the molar mass of lithium fluoride (LiF) by adding the atomic masses of lithium (Li) and fluorine (F). Use the periodic table values: approximately 6.94 g/mol for Li and 18.998 g/mol for F.
2. Calculate the molar mass of LiF using the formula: \(\text{Molar mass of LiF} = \text{Atomic mass of Li} + \text{Atomic mass of F}\).
3. Use the relationship between mass, moles, and molar mass given by the formula: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\).
4. Substitute the given mass (39 grams) and the calculated molar mass of LiF into the formula to find the number of moles: \(\text{moles of LiF} = \frac{39\ \text{g}}{\text{molar mass of LiF}}\).
5. Compare the calculated number of moles to the options provided to determine which quantity is equivalent to 39 grams of LiF.