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Chemical reaction and equation

Which of the statements about the reaction below are incorrect?
2PbO(s) + C(s) → 2Pb(s) + CO2 (g)
(a) Lead is getting reduced.
(b) Carbon dioxide is getting oxidised.
(c) Carbon is getting oxidised.
(d) Lead oxide is getting reduced.
(i) (a) and (b)
(ii) (a) and (c)
(iii) (a), (b) and (c)
(iv) all

13/11/2024

Science

10th

Chemical reaction and equation

Identify the substances that are oxidised and the substances that are reduced in the following reactions.
(i) 4Na(s) + O2 (g) → 2Na2O(s)
(ii) CuO(s) + H2 (g) → Cu(s) + H2O(l)

13/11/2024

Science

10th

Chemical reaction and equation

Give an example of a double displacement reaction other than the one given in Activity 1.10.

13/11/2024

Science

10th

Chemical reaction and equation

Why does the colour of copper sulphate solution change when an iron nail is dipped in it?

13/11/2024

Science

10th

Chemical reaction and equation

Why is the amount of gas collected in one of the test tubes in Activity 1.7 double of the amount collected in the other? Name this gas.

13/11/2024

Science

10th

Chemical reaction and equation

A solution of a substance ‘X’ is used for whitewashing.
(i) Name the substance ‘X’ and write its formula.
(ii) Write the reaction of the substance ‘X’ named in (i) above with water.

13/11/2024

Science

10th

Chemical reaction and equation

Write a balanced chemical equation with state symbols for the following reactions.
(i) Solutions of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride.
(ii) Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride solution and water.

13/11/2024

Science

10th

Chemical reaction and equation

Write the balanced equation for the following chemical reactions.
(i) Hydrogen + Chlorine → Hydrogen chloride
(ii) Barium chloride + Aluminium sulphate → Barium sulphate + Aluminium chloride
(iii) Sodium + Water → Sodium hydroxide + Hydrogen

13/11/2024

Science

10th

Chemical reaction and equation

Why should a magnesium ribbon be cleaned before burning in air?

13/11/2024

Science

9th

Statistics

Given a data set with values 12, 15, 20, 20, 25, 30, and 35, calculate the mean, median, and mode of this data set.

12/11/2024

Mathematics

12th (Science)