Question

When sugar is stirred with a spoon in a glass of water, more sugar is dissolved and faster. Why?

• A. Spoon acts as a catalyst
• B. On stirring, temperature increases
• C. Stirring increases the rate of interaction
• D. Spoon increases the attraction between the molecules of water and sugar

Answer 1

Answer: (B), (C)

Stirring increases the rate of interaction
On stirring, temperature increases

Stirring, or agitation helps to disperse the particles of sugar throughout the water, which is another way of increasing the surface area of the sugar and accelerating the time it takes to dissolve. The stirring motion also increases kinetic energy, which increases the temperature of the solution – and that's the next way to make the sugar dissolve more quickly. An increase in the kinetic energy of the constituent particle increases the rate of interaction as well as the temperature of the solution.

Hence, option $B$ & $C$ are correct.