What is the minimum amount of heat required to completely melt 20.0 grams of ice at its melting point?

(1) 20.0 J (3) 6680 J

(2) 83.6 J (4) 45 200 J

The right answer is option 3.

Explanation:

The minimum amount of heat required to melt ice is:

Where and is the latent heat of fussion, measured in kg and kJ/kg, respectively.

The right answer is option 3.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e