English Medium कक्षा १० - CBSE Important Questions for Science

A spatula full of sodium carbonate is taken in a test tube and 2 mL of dilute ethanoic acid is added to it.

Suggest a method of testing the gas liberated in the reaction.

Name the oxidising agent used in the conversion of ethanol to ethanoic acid.

Write the chemical equation for the ethanol to ethanoic acid of an oxidation reaction.

How is ethanol to ethanoic acid an oxidation reaction different from the reaction in which ethanol burns in the presence of oxygen?

How are oxygen and carbon dioxide transported in human beings?

Describe the structure and functioning of nephrons.

What would be the consequences of a deficiency of haemoglobin in our bodies?

Explain why, when air is taken in and let out during breathing, the lungs always contain a residual volume of air.

Draw a sectional view of the human heart and label on it Aorta, Pulmonary arteries, Vena cava, Left ventricle.

What is haemoglobin? State the consequences of deficiency of haemoglobin in our bodies. 

A student has set up "CO₂ is released during respiration”. After about 1 hour he observes no change in the water level in the delivery tube. Write two possible resons for the failure of the experiment. 

Answer the following question.
A gas is released during photosynthesis. Name the gas and also state the way by which the gas is evolved.

Write three types of blood vessels. Give one important feature of each.

Answer the following question.
How is O₂ and CO₂ transported in human beings?

With the reference to four gases CO₂, CO, Cl₂ and O₂, which one of the options in the table is correct?

How is lymph an important fluid involved in transportation? If lymphatic vessels get blocked, how would it affect the human body? Elaborate.

What is the other name of 'tissue fluid'? Write its two functions.

What is the purpose of making urine in the human body?

Name the organs that store and release the urine.

Why do arteries have thick and elastic walls whereas veins have valves?