Question

The weight of an empty China dish is 39 g and when a saturated solution of potassium

nitrate is poured into it, its weight is 108 g at

50°C

. After evaporating the solution to

dryness, if the weight of the dish along with the crystals is 72 g then the solubility of

potassium nitrate at

50°C

is _____.

Options:

(a) 83.9

(b) 95.6

(c) 91.6

(d) 87.4
Please answer along with the explanation.

Answer 1

Answer:

The solid-vapor curve, labeled AB in Figure 2, indicates the temperatures and pressures at which ice and water vapor are in equilibrium. These temperature-pressure data pairs correspond to the sublimation, or deposition, points for water. If we could zoom in on the solid-gas line in Figure 2, we would see that ice has a vapor pressure of about 0.20 kPa at −10 °C. Thus, if we place a frozen sample in a vacuum with a pressure less than 0.20 kPa, ice will sublime. This is the basis for the “freeze-drying” process often used to preserve foods, such as the ice cream shown in Figure 3.

Explanation: