A solution contains 0.400 L of 0.350 M KBr. What is the mass of KBr (in grams) present in the solution?

• A. 9.4 g
• B. 11.2 g
• C. 16.7 g
• D. 23.4 g

Answer: (C)

Verified step by step guidance

1. Identify the given information: volume of solution \(V = 0.400\ \text{L}\) and molarity \(M = 0.350\ \text{mol/L}\) of KBr.
2. Recall that molarity is defined as moles of solute per liter of solution, so calculate the moles of KBr using the formula: \(\text{moles} = M \times V\).
3. Calculate the moles of KBr by multiplying the molarity by the volume: \(\text{moles of KBr} = 0.350 \times 0.400\).
4. Find the molar mass of KBr by adding the atomic masses of potassium (K) and bromine (Br). Use the periodic table values: approximately 39.1 g/mol for K and 79.9 g/mol for Br, so \(\text{molar mass of KBr} = 39.1 + 79.9\) g/mol.
5. Calculate the mass of KBr by multiplying the moles of KBr by its molar mass: \(\text{mass} = \text{moles of KBr} \times \text{molar mass of KBr}\).