Test: Change of Phase - NEET MCQ

Adding heat energy to water increases the motion of the water molecules and the molecules of food coloring. The faster moving molecules cause the food coloring to mix into the water faster. The water molecules and food coloring molecules in cold water don't move as quickly as in hot water.

The net flow of solute is from its higher concentration to lower concentration.

The temperature and pressure at which all three phases of a substances coexist is called triple point​. By the definition.

Increasing the temperature of liquid, increases the average K.E. of the molecules. The molecules start moving vigorously in all the directions, thereby increasing and the inter-molecular space between them. Thus, the liquid changes into gas.

In general, the liquids tend to expand when their temperature increases. For example, the same mass of boiling water occupies more volume at 100 degrees Celsius than at 20 degrees Celsius. Therefore, increasing temperature decreases density.

As the pressure increases between the skates and ice, the ice starts melting below 0^o C.

Latent heat is a measure of the heat energy (Q) per mass (m) released or absorbed during a phase change. The SI units are joule per kilogram [J/kg]

When ice melts the volume decreases and an increase in pressure will support this phenomena according to Le Chatalier’s rule.

When a substance undergoes a phase change (such as melting or boiling), the temperature remains constant during the process.

The amount of heat required is given by the formula Q = mL, where L is the latent heat of the substance.

The options containing Δτ (change in temperature) or S (specific heat) are incorrect because there is no temperature change during a phase change, and latent heat, not specific heat, is used.

Therefore, the correct formula is Q = mL.

So, Option D is the correct answer.

x = 0, Saturated liquid
x = 1, Saturated vapor

As x value lies between 0 and 1, therefore it is a mixture of saturated liquid and saturated vapor.