Carbon and its Compounds — Science STD 10 — Question

What colour do the following indicators turn when added to a base or alkali (such as sodium hydroxide)?

1. Methyl orange.
2. Litmus.
3. Red cabbage extract.

If the 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?

What colours lie on the two sides of the ‘green colour’ in the spectrum of white light?

State whether a solution is acidic, alkaline or neutral if its pH is:

1. 9
2. 4
3. 7
4. 1
5. 10
6. 3

Potassium metal reacts with water to give potassium hydroxide and hydrogen gas. Write a balanced chemical equation for this reaction.

For what position of an object a real, diminished image is formed by a convex lens?

What happens when:

1. Piece of magnesium metal is placed in copper sulphate solution?
2. A piece of copper metal is placed in iron sulphate solution?

Name the element which is in:

1. First group and third period.
2. Seventeenth group and second period.

Name two metals which are both malleable and ductile.