Measure the temperature of water in normal conditions. If you add the following substance to the water, do you find any difference in temperature? Predict and verify. Water temperature in Celsius Water (100 ml each time mixed with two tablespoonful of each) Prediction Temperature of the solution immediately after mixing the substance Glucose Decrease Washing powder Baking soda Sugar Common salt Do you find any change in temperature before and immediately after mixing the above substances in water? If yes, what could be the reason?

The water remains in the liquid state at room temperature. The temperature of normal water is calculated as 0 ° C . The addition of different substances in the water causes the chemical reactions with the water molecule. The chemical reactions can be of two types on the basis of release or utilization of energy. These are named as follows: Exothermic reactions Endothermic reaction When we add washing powder, baking soda, and common salt in the water, the reaction takes place causes the release of energy in the form of heat, therefore the temperature of water increases. When we add glucose and sugar in the water, the reaction involves the absorption of heat energy, therefore the temperature of water decreases. The change in the temperature can be calculated by using laboratory thermometer. Water temperature in Celsius Water (100 ml each time mixed with two tablespoonfuls of each) Prediction Temperature of the solution immediately after mixing the substance 0 ° C Glucose Decrease Decrease 0 ° C Washing powder Increase Increase 0 ° C Baking soda Increase Increase 0 ° C Sugar Decrease Decrease 0 ° C Common salt Increase Increase

E M B I B E

Science Class - 7>Chapter 5 - Heat - Measurement>Improve your learning>Q 16

MEDIUM

7th Telangana Board

IMPORTANT

Earn 100

Draw the diagram of a clinical thermometer and label its parts. What is the use of kink in clinical thermometer?

Important Questions on Heat - Measurement

MEDIUM

7th Telangana Board

IMPORTANT

Science Class - 7>Chapter 5 - Heat - Measurement>Improve your learning>Q 17

Draw the diagram of a laboratory thermometer and label its parts. How does it differ from a clinical thermometer?

EASY

7th Telangana Board

IMPORTANT

Science Class - 7>Chapter 5 - Heat - Measurement>Improve your learning>Q 18

Measure the body temperature between fingers, under the tongue, armpit, folded hands, folded legs etc., Is it the same? Does the body temperature remain the same after jumping ten times? Why?

EASY

7th Telangana Board

IMPORTANT

Science Class - 7>Chapter 5 - Heat - Measurement>Improve your learning>Q 19

Collect information from hospital/ health centre about the precautions to be taken while reading temperature with a clinical thermometer.

MEDIUM

7th Telangana Board

IMPORTANT

Science Class - 7>Chapter 5 - Heat - Measurement>Improve your learning>Q 20

Measure the temperature of water in normal conditions. If you add the following substance to the water, do you find any difference in temperature? Predict and verify.

Water temperature in Celsius	Water (100 ml each time mixed with two tablespoonful of each)	Prediction	Temperature of the solution immediately after mixing the substance
	Glucose	Decrease
	Washing powder
	Baking soda
	Sugar
	Common salt