Question

The number of grams of KF in 45.0 ml of 0.200 M KF?

a) 0.0191 g
b) 522 g
c) 13 g
d) 0.522 g
e) 45.0 g

Answer 1

The mass of KF in 45.0 mL of 0.200 M KF solution is calculated to be 0.522 g, which corresponds to answer choice (d). This is found by using the relationship between molarity, volume, and molar mass.

Step-by-step explanation:

The question is on calculating the mass of KF (potassium fluoride) in a solution with a given concentration and volume. To find the mass, we can use the equation: mass (g) = molarity (M) × volume (L) × molar mass of KF.

The molar mass of KF can be found by adding the atomic masses of K (potassium) and F (fluoride), which is approximately 58.10 g/mol.

First, convert the volume from milliliters to liters: 45.0 mL = 0.045 L (since there are 1000 mL in 1 L). Then use the molarity of the solution (0.200 M) and the molar mass of KF to obtain the mass:

mass = 0.200 M × 0.045 L × 58.10 g/mol = 0.522 g

This indicates that the answer is (d) 0.522 g, which is the mass of KF in 45.0 mL of 0.200 M KF solution.