試題詳解

16. A mixture of solid NaCl and CaCl₂ contains 10.0 g of NaCl, and an unknown amount of CaCl₂. When the entire mixture is dissolved in 1.00 kg of water, the boiling point changes by 0.25 °C. What mass of CaCl₂ was in the original mixture? Kb for water is 0.512 K·kg mol⁻¹.
(A) 5.4 g
(B) 8.1 g
(C) 35.2 g
(D) 21.6 g
(E) 17.6 g