Question

(40 points)

It takes 1 minute for a certain amount of potassium phosphate (KH2PO4) to dissolve in 100 grams of water at 50 °C.

Which of the following will most likely happen if the same sample of potassium phosphate is dissolved in 100 grams of water at 20 °C?
The sample will dissolve in exactly 1 minute.
The sample will dissolve in more than 1 minute.
The collision between particles of the sample will increase.
The collision between particles of the sample will remain constant.

Answer 1

Answer: the answer is B

Explanation: i took the test and got it right

Answer 2

The sample will dissolve in more than 1 minute.

Step-by-step explanation:

In order to answer this question, we have to consider several significant aspects:

• temperature is directly proportional to kinetic energy, that is, the greater the temperature, the greater the kinetic energy. Since kinetic energy measures velocity of the particles, this means that the greater the temperature, the greater the velocity of the individual ions of potassium phosphate;
• we may conclude from the first fact that the number of collisions in a given amount of time will then increase due to an increase in velocity;
• it also follows that the greater the temperature, the faster our salt dissolves due to an increase in the number of successful collisions.

This means that at a lower temperature, the sample will dissolve in a longer period of time.