Which of the following would produce a 0.100 m KI (molar mass = 166.0 g/mol) solution?

• A. 1.66 g KI dissolved in 100.0 g water
• B. 16.6 g KI dissolved in 1.00 L water
• C. 0.166 g KI dissolved in 100.0 g water
• D. 1.66 g KI dissolved in 1.00 L water

Answer: (A)

Verified step by step guidance

1. Understand that molality (m) is defined as moles of solute per kilogram of solvent, given by the formula: \(m = \frac{\text{moles of solute}}{\text{kg of solvent}}\).
2. Identify the given molality value, which is 0.100 m, meaning 0.100 moles of KI per 1 kilogram of water.
3. Calculate the moles of KI needed for 100.0 g (0.100 kg) of water using the relation: \(\text{moles of KI} = m \times \text{kg of water} = 0.100 \times 0.100\) kg.
4. Convert the moles of KI to grams using the molar mass of KI (166.0 g/mol) with the formula: \(\text{mass of KI} = \text{moles of KI} \times 166.0\) g/mol.
5. Compare the calculated mass of KI with the given options to determine which corresponds to a 0.100 m solution when dissolved in 100.0 g of water.