English Medium Class 10 - CBSE Question Bank Solutions

An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be ______.

Food cans are coated with tin and not with zinc because ______.

You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.

Differentiate between metals and non-metals on the basis of their chemical properties.

Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).

What would be the electron dot structure of carbon dioxide which has the formula CO₂?

What would be the electron dot structure of a molecule of sulphur which is made up of eight atoms of sulphur? (Hint – the eight atoms of sulphur are joined together in the form of a ring.)

Ethane, with the molecular formula C₂H₆ has ______.

Butanone is a four-carbon compound with the functional group:

Explain the nature of the covalent bond using the bond formation in CH₃Cl.

How does chemical coordination occur in plants?

If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?

How does the creation of variations in a species promote survival?

2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid.

 Why are most carbon compounds poor conductors of electricity?

A student added few pieces of aluminium metal to two test tubes A and B containing aqueous solutions of iron sulphate and copper sulphate. In the second part of her experiment, she added iron metal to another test tubes C and D containing aqueous solutions of aluminium sulphate and copper sulphate.

In which test tube or test tubes will she observe colour change? On the basis of this experiment, state which one is the most reactive metal and why.

What is the general name of chemical substances which bring about control and coordination in plants?

Which of the following is not a plant hormone?

Which of the processes, sexual reproduction or asexual reproduction, bring about maximum variations in the offsprings?