What happens when dilute hydrochloric acid is added to iron fillings? Tick the correct answer

Which of the following is not a physical change?

A dilute ferrous sulphate solution was gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation?

Which among the following statement(s) is (are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to
(i) the formation of silver by decomposition of silver chloride
(ii) sublimation of silver chloride
(iii) decomposition of chlorine gas from silver chloride
(iv) oxidation of silver chloride

Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?
(i) Displacement reaction
(ii) Precipitation reaction
(iii) Combination reaction
(iv) Double displacement reaction

Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is

Which of the following gases can be used for storage of fresh sample of an oil for a long time?

Which one of the following processes involves chemical reactions?

Chemically rust is

Methane on combustion gives

Write the decomposition of ferrous sulphate with balanced chemical equation.

Name the chemical used in black and white photography.

Name the gases evolved when lead nitrate is heated.

Give the formula for quicklime.

Name the different forms of energy required for breaking down the reactants in decomposition reaction.

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

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

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

Give an example of a double displacement reaction other than the reaction of barium chloride with sodium sulphate.

Write the balanced chemical equations for the following reactions.
(a) Calcium hydroxide + Carbon dioxide \(\rightarrow\) Calcium carbonate + Water
(b) Zinc + silver nitrate \(\rightarrow\) Zinc nitrate + Silver
(c) Aluminium + Copper chloride \(\rightarrow\) Aluminium chloride + Copper
(d) Barium chloride + Potassium Sulphate \(\rightarrow\) Barium sulphate + Potassium chloride

(a) In the following reactions, name the reactants, which undergoes oxidation and reduction:
(i) CuO(s) + H₂(g) \(\longrightarrow \) Cu(s) + H₂O(g)
(ii)CuO(s) + Zn(s) \(\longrightarrow \) ZnO(s) + Cu(s)
(b) State one industrial application of reduction.

(a) Write chemical equations.
(i) When carbon dioxide gas is passed through lime water.
(ii)When excess of carbon dioxide gas is passed through lime water.
(b) List two natural forms of calcium carbonate.

What happens when a piece of
(a) Zinc metal is added to copper sulphate solution?
(b) Aluminium metal is added to dilute hydrochloric acid?
(c) Silver metal is added to copper sulphate solution? Write the balanced chemical equation if the reaction occurs.

On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, white precipitate is obtained.
(a) Write a balanced chemical equation of the reaction involved.
(b) What other name can be given to this precipitation reaction?
(c) On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?