P-1 Metallurgy — Science STD 10 — Question

Explain why, metals usually do not liberate hydrogen gas with dilute nitric acid.

Explain why does the lime water turns milky in the reaction of acetic acid with sodium carbonate.

When the material A mined from the earth is heated strongly in an insufficient supply of air, it produces a solid fuel B which consists mainly of carbon. When another material C obtained from trees is heated in an insufficient supply of air, it produces another solid fuel D which also consists mainly of carbon. Name A, B, C and D.

What is the relationship between the cell division and formation of new organism of the same species by earlier existing organism?

State the factors which affect the speed (or rate) of a reaction.

Explain with a suitable diagram, how a concave mirror converges a parallel beam of light rays. Mark clearly the pole, focus and centre of curvature of concave mirror in this diagram.

An element A has an atomic number of 6. Another element B has 17 electrons in its one neutral atom.

1. N which groups of the periodic table would you expect to find these elements?
2. What type of bond is formed between A and B?
3. Suggest a formula of the compound formed between A and B.

How does a universal indicator work?

Explain the following reaction with example.
Addition reaction

Suppose you are standing on a tall ladder. If your distance from the centre of the earth is 2R, what will be your weight?