What mass of KBr is present in 75.0 mL of a 0.250 M KBr solution?

• A. 3.53 g
• B. 1.41 g
• C. 0.25 g
• D. 0.75 g

Answer: (B)

Verified step by step guidance

1. Identify the given information: volume of solution = 75.0 mL, molarity (M) = 0.250 mol/L, and you need to find the mass of KBr.
2. Convert the volume from milliliters to liters because molarity is in moles per liter: \(\text{Volume (L)} = \frac{75.0}{1000}\).
3. Calculate the number of moles of KBr using the molarity formula: \(\text{moles} = M \times \text{Volume (L)} = 0.250 \times \text{Volume (L)}\).
4. Find the molar mass of KBr by adding the atomic masses of potassium (K) and bromine (Br): \(\text{Molar mass of KBr} = \text{atomic mass of K} + \text{atomic mass of Br}\).
5. Calculate the mass of KBr by multiplying the moles by the molar mass: \(\text{mass} = \text{moles} \times \text{molar mass}\).