Chemical Reactions and Equations Science - Chemical Reactions and Equations

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?

1. Displacement reaction.
2. Precipitation reaction.
3. Combination reaction.
4. Double displacement reaction.

In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature?

In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the following can be used in place of lead nitrate?

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 one of the following processes involve chemical reactions?

1. Storing of oxygen gas under pressure in a gas cylinder.
2. Liquefaction of air.
3. Keeping petrol in a china dish in the open.
4. Heating copper wire in presence of air at high temperature.

Which of the following statements about the given reaction are correct?
3Fe(s) + 4H₂O(g) → Fe₃O₄(s) + 4H₂(g)

1. Iron metal is getting oxidised.
2. Water is getting reduced.
3. Water is acting as reducing agent.
4. Water is acting as oxidising agent.

1. 1, 2 and 3
2. 3 and 4
3. 1, 2 and 4
4. 2 and 4

Which of the following is not a physical change?

1. Boiling of water to give water vapour.
2. Melting of ice to give water.
3. Dissolution of salt in water.
4. Combustion of Liquefied Petroleum Gas (LPG).

Which of the following is (are) an endothermic process(es)?

1. Dilution of sulphuric acid.
2. Sublimation of dry ice.
3. Condensation of water vapours.
4. Evaporation of water.

1. 1 and 3
2. 2 Only
3. 3 Only
4. 2 and 4

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

1. Carbon dioxide or oxygen.
2. Nitrogen or oxygen.
3. Carbon dioxide or helium.
4. Helium or nitrogen.

Write a balanced chemical equation for each of the following reaction and also classify them.
Lead acetate solution is treated with dilute hydrochloric acid to form lead chloride and acetic acid solution.

Write a balanced chemical equation for each of the following reaction and also classify them.
A piece of sodium metal is added to absolute ethanol to form sodium ethoxide and hydrogen gas.

Which among the following changes are exothermic or endothermic in nature?

1. Decomposition of ferrous sulphate.
2. Dilution of sulphuric acid.
3. Dissolution of sodium hydroxide in water.
4. Dissolution of ammonium chloride in water.

Identify the reducing agent in the following reaction.
H₂O + F₂ → HF + HOF

Identify the reducing agent in the following reaction.
Fe₂O₃ + 3CO → 2Fe + 3CO₂

Write the balanced chemical equation for the following reaction and identify the type of reaction.
Chlorine gas is passed in an aqueous potassium iodide solution to form potassium chloride solution and solid iodine.

Write the balanced chemical equation for the following reaction and identify the type of reaction.
Sodium hydroxide solution is treated with acetic acid to form sodium acetate and water.

Write the balanced chemical equations for the following reaction.
Sodium carbonate on reaction with hydrochloric acid in equal molar concentrations gives sodium chloride and sodium hydrogencarbonate.

Write the balanced chemical equations for the following reaction.
Sodium hydrogencarbonate on reaction with hydrochloric acid gives sodium chloride, water and liberates carbon dioxide.

Write the balanced chemical equations for the following reaction.
Sodium carbonate on reaction with hydrochloric acid in equal molar concentrations gives sodium chloride and sodium hydrogencarbonate.

Write the balanced chemical equations for the following reaction.
Copper sulphate on treatment with potassium iodide precipitates cuprous iodide (Cu₂I₂), liberates iodine gas and also forms potassium sulphate.

Write the balanced chemical equation for the following reaction and identify the type of reaction.
Thermit reaction, iron (III) oxide reacts with aluminium and gives molten iron and aluminium oxide.

Write the balanced chemical equation for the following reaction and identify the type of reaction.
Sodium hydroxide solution is treated with acetic acid to form sodium acetate and water.

A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining.

1. Why do silver articles turn black when kept in the open for a few days? Name the phenomenon involved.
2. Name the black substance formed and give its chemical formula.

On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, white precipitate is obtained.

1. Write a balanced chemical equation of the reaction involved.
2. What other name can be given to this precipitation reaction?
3. On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?

Ferrous sulphate decomposes with the evolution of a gas having a characteristic odour of burning sulphur. Write the chemical reaction involved and identify the type of reaction.

A substance X, which is an oxide of a group 2 element, is used intensively in the cement industry. This element is present in bones also. On treatment with water it forms a solution which turns red litmus blue. Identify X and also write the chemical reactions involved.

What happens when a piece of.

1. Zinc metal is added to copper sulphate solution?
2. Aluminium metal is added to dilute hydrochloric acid?
3. Silver metal is added to copper sulphate solution? Also, write the balanced chemical equation if the reaction occurs.

Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid, whereas copper does not. Explain why?

What happens when a piece of.

1. Zinc metal is added to copper sulphate solution?
2. Aluminium metal is added to dilute hydrochloric acid?
3. Silver metal is added to copper sulphate solution? Also, 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.

1. Write a balanced chemical equation of the reaction involved.
2. What other name can be given to this precipitation reaction?
3. On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?

Ferrous sulphate decomposes with the evolution of a gas having a characteristic odour of burning sulphur. Write the chemical reaction involved and identify the type of reaction.

A substance X, which is an oxide of a group 2 element, is used intensively in the cement industry. This element is present in bones also. On treatment with water it forms a solution which turns red litmus blue. Identify X and also write the chemical reactions involved.

During the reaction of some metals with dilute hydrochloric acid, following observations were made.

1. Silver metal does not show any change.
2. The temperature of the reaction mixture rises when aluminium (Al) is added.
3. The reaction of sodium metal is found to be highly explosive.
4. Some bubbles of a gas are seen when lead (Pb) is reacted with the acid.

Explain these observations giving suitable reasons.

Which among the following are physical or chemical changes?

1. Evaporation of petrol.
2. Burning of Liquefied Petroleum Gas (LPG).
3. Heating of an iron rod to red hot.
4. Curdling of milk.
5. Sublimation of solid ammonium chloride.

On heating blue coloured powder of copper (II) nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas X is formed.

1. Write a balanced chemical equation of the reaction.
2. Identity the brown gas X evolved.
3. Identity the type of reaction.
4. What could be the pH range of aqueous solution of the gas X?

You are provided with two containers made up of copper and aluminium. You are also provided with solutions of dilute HCl, dilute HNO₃, ZnCl₂ and H₂O. In which of the above containers these solutions can be kept?

Which among the following are physical or chemical changes?

1. Evaporation of petrol.
2. Burning of Liquefied Petroleum Gas (LPG).
3. Heating of an iron rod to red hot.
4. Curdling of milk.
5. Sublimation of solid ammonium chloride.

What happens when zinc granules are treated with dilute solution of H₂SO₄ , HCl, HNO₃, NaCl and NaOH, also write the chemical equations if reaction occurs.

On heating blue coloured powder of copper (II) nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas X is formed.

1. Write a balanced chemical equation of the reaction.
2. Identity the brown gas X evolved.
3. Identity the type of reaction.
4. What could be the pH range of aqueous solution of the gas X?

During the reaction of some metals with dilute hydrochloric acid, following observations were made.

1. Silver metal does not show any change.
2. The temperature of the reaction mixture rises when aluminium (Al) is added.
3. The reaction of sodium metal is found to be highly explosive.
4. Some bubbles of a gas are seen when lead (Pb) is reacted with the acid.

Explain these observations giving suitable reasons.