Chemical Reactions and Equations: Class 10 Chemistry Q&A
120 free answers on Chemical Reactions and Equations (Chemistry) for Class 10 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- ChemistryClass 10ICSE
. A metal salt MX when exposed to light splits up to form metal M and a gas X2. Metal M is used in making ornaments whereas gas X2 is used in making bleaching powder. The salt MX is itself used in black and white photography. (a) What do you think metal M is? (b) What could be gas X2? (c) Name the metal salt MX. (d) Name any two salt solutions which on mixing together can produce a precipitate of salt MX. (e) What type of chemical reaction takes place when salt MX is exposed to light? Write the equation of the reaction.
Silver will be metal X Chlorine is the gas evolved when MX salt is exposed to light Silver chloride is the metal salt MX which is used in black and white Silver nitrate and Sodium chloride are the two salt solutions which on mixing together produce a precipitate of salt silver chloride Decomposition reaction is the reaction taking place here when compound decomposes to form simpler new products. Silver chloride decomposes to form silver and chlor
- ChemistryClass 10ICSE
When a strip of red-brown metal X is placed in a colourless salt solution YNO3 then metal Y is set free and a blue coloured salt solution X(NO3)2 is formed. The liberated metal Y forms a shining white deposit on the strip of metal X. (a) What do you think metal X is? (b) Name the salt YNO3. (c) What could be metal Y? (d) Name the salt X(NO3)2 (e) What type of reaction takes place between metal X and salt solution YNO3?
Copper is the metal X which is a red brown strip Silver nitrate is the salt YNO3 which is a colourless salt Silver is the metal formed Y upon reaction of copper and silver nitrate solution thus it forms a shining white deposit on the strip metal X Copper nitrate is X(NO3)2 the salt formed which is blue coloured as copper is present in it Displacement reaction will be the type of reaction taking place here Cu(s) + 2AgNO3(aq) → Cu(NO3)2(aq) +
- ChemistryClass 10ICSE
A red-brown metal X forms a salt XSO4. When hydrogen sulphide gas is passed through an aqueous solution of XSO4, then a black precipitate of XS is formed along with sulphuric acid solution. (a) What could the salt XSO4 be? (b) What is the colour of salt XSO4? (c) Name the black precipitate XS. (a) By using the formula of the salt obtained in (a) above, write an equation of the reaction which takes place when hydrogen sulphide gas is passed through its aqueous solution. (e) What type of chemical reaction takes place in this case?
Copper sulphate will be the salt formed named as XSO4 Blue colour is the colour of the salt as it is copper sulphate Copper sulphide is responsible for the black precipitate XS CuSO4 (aq) + H2S (g) → CuS (s) + H2SO4 (aq) Double displacement reaction in which reactant ions exchange places to form new products which results in precipitation reaction.
- ChemistryClass 10ICSE
Two metals X and Y form the salts XSO4 and Y2SO4, respectively. The solution of salt XSO4 is blue in colour whereas that of Y2SO4 is colourless. When barium chloride solution is added to XSO4 solution, then a white precipitate Z is formed along with a salt which turns the solution green. And when barium chloride solution is added to Y2SO4 solution, then the same white precipitate Z is formed along with colourless common salt solution. (a) What could the metals X and Y be? (b) Write the name and formula of salt XSO4. (c) Write the name and formula of salt Y2SO4. (d) What is the name and formula of white precipitate Z? Write the name and formula of the salt which turns the solution green in the first case.
Copper is Metal X and Metal Y is Both forms sulphate salts on reaction Copper sulphate, CuSO4is XSO4, the salt formed which is blue in colour Sodium sulphate, Na2SO4 is Y2SO4 which is a colourless salt Barium sulphate, BaSO4 is Z which is a white precipitate formed upon the reaction when barium chloride is added to copper sulphate and turns the solution green Copper chloride, CuCl2 is the salt having yellowish brown colour which turns the solutio
- ChemistryClass 10ICSE
A metal X forms a water soluble salt XNO3. When an aqueous solution of XNO3 is added to common salt solution, then a white precipitate of compound Y is formed alongwith sodium nitrate solution. Metal X is said to be the best conductor of electricity and it does not evolve hydrogen when put in dilute hydrochloric acid. (a) What is metal X ? (b) What is salt XNO3? (c) Name the compound Y. (d) Write the chemical equation of the reaction which takes place on reacting XNO3 solution and common salt solution giving the physical states of all the reactants and products. What type of chemical reaction is illustrated by the above equation?
Silver (Ag) will be metal which conducts electricity and does not evolve hydrogen when put in dilute hydrochloric acid Silver nitrate (AgNO3) is XNO3 which is reacts with NaCl (common salt) to give white precipitate Silver chloride (AgCl) is the compound Y formed which is the white precipitate formed from the reaction of silver nitrate and sodium chloride. AgNO3(aq) + NaCl (aq)→ AgCl (s) + NaNO3 (aq) Double displacement reaction
- ChemistryClass 10ICSE
When a black metal compound XO is heated with a colourless gas Y2, then metal X and another compound Y2O are formed. Metal X is red-brown in colour which does not react with dilute acids at all. Gas Y2 can be prepared by the action of a dilute acid on any active metal. The compound Y2O is a liquid at room temperature which can turn anhydrous copper sulphate blue. (a) What do you think is metal X? (b) What could be gas Y 2? (c) What is compound XO? (d) What is compound Y2O? (e) Write the chemical equation of the reaction which takes place on heating XO with Y2. What type of chemical reaction is illustrated in the above equation?
Copper (Cu) will be the metal X which is red brown in colour and does not react with dilute acids Hydrogen (H2) is the colourless gas Y2 Copper oxide (CuO) will be the compound XO a black metal compound Water (H2O) is the product formed Y2O CuO + H2 →Cu + H2O Displacement reaction (which is also a redox reaction).Which one active element displaces a less reactive element from its salt solution
- ChemistryClass 10ICSE
A strip of metal X is dipped in a blue coloured salt solution YSO4. After some time, a layer of metal Y from the salt solution is formed on the surface of metal strip X. Metal X is used in galvanisation whereas metal Y is used in making electric wires. Metal X and metal Y together form an alloy Z. (a) What could metal X be? (b) What could metal Y be? (c) Name the metal salt YSO4 (d) What type of chemical reaction takes place when metal X reacts with salt solution YSO4? Write the equation of the chemical reaction involved. Name the alloy Z.
Metal X is Zinc (Zn) Metal Y is Copper (Cu) Copper sulphate (CuSO4) is named as YSO4 Displacement reaction;Displacement reaction is a reaction in which one active element displaces a less reactive element from its salt solution CuSO4 (aq) + Zn (s) → ZnSO4 (aq) + Cu (s) Brass
- ChemistryClass 10ICSE
When hydrogen burns in oxygen, water is formed and when water is electrolysed, then hydrogen and oxygen are produced. What type of reaction takes place? (a) In the first case? In the second case?
Combination reaction of hydrogen and oxygen gas which results in the formation of water Decomposition reaction is that water electrolysis which breakdown hydrogen gas and oxygen gas
- ChemistryClass 10ICSE
A colourless lead salt, when heated, produces a yellow residue and brown fumes. (a) Name the lead salt. (b) Name the brown fumes. (c) Write a chemical equation of the reaction involved.
Lead nitrate is the lead salt Nitrogen dioxide is responsible for the brown fumes 2Pb(NO3)2→ 2PbO + 4NO2
- ChemistryClass 10ICSE
When a green iron salt is heated strongly, its colour finally changes to brown and odour of burning sulphur is given out. (a) Name the iron salt. (b) Name the type of reaction that takes place during the heating of iron salt. Write a chemical equation for the reaction involved.
Ferrous Decomposition Ferrous sulphate crystal loses water and forms anhydrous ferrous sulphate and further decomposes to form ferric oxide, sulphur dioxide and sulphur trioxide 2FeSO4→ Fe2O3 + SO2+ SO3
- ChemistryClass 10ICSE
(a) Decomposition reaction as well as displacement reaction(a) Combination reaction as well as double displacement reaction (b) Redox reaction as well as displacement reaction (c) Double displacement reaction as well as Redox reaction
Option(c) is the answer. Redox reaction as well as displacement reaction takes place because magnesium get oxidized here and copper reduces. Therefore it is reduction and magnesium displaces copper in the solution as being more reactive. Thus becomes displacement reaction
- ChemistryClass 10ICSE
Consider the reaction: KBr (aq) + AgNO3 (aq) → KNO3 (aq) + AgBr (s) This is an example of: (a) Decomposition reaction (b) Combination reaction (c) Double displacement reaction Displacement reaction
Option (c) is the answer. Double displacement reaction is the given reaction that is exchange of ions takes place between both the reactants. You are given the following chemical equation: Mg(s) + CuO(s) →MgO(s) + Cu (s)
- ChemistryClass 10ICSE
Which of the following can be decomposed by the action of light? (a) NaCl (b) KCl (c)AgCl (d) CuCl
Option (c) is the answer. Here AgCl is decomposed by the action of light. The reaction which reactants split into simpler products is called decomposition reaction so here silver chloride can be decomposed by the action of light.
- ChemistryClass 10ICSE
The process of respiration is: (a) An oxidation reaction which is endothermic (b) A reduction reaction which is exothermic (c) A combination reaction which is endothermic An oxidation reaction which is exothermic
Option (d) is the answer. During digestion the food what we have taken breakdown and gives energy. If we are having carbohydrate content food items, it break downs to glucose and it combines with oxygen to give energy and thus addition of oxygen takes place and energy is also released
- ChemistryClass 10ICSE
Consider the following equation of the chemical reaction of a metal M: 4M + 3O2→ 2M2O3 The equation represents: (a) Combination reaction as well as reduction reaction (b) Decomposition reaction as well as oxidation reaction (c) Oxidation reaction as well as displacement reaction Combination reaction as well as oxidation reaction
Option (d) is the answer. In the above reaction, Metal combines with the oxygen to form a single compound which is a combination reaction and here addition of oxygen takes place so it is oxidation reaction
- ChemistryClass 10ICSE
A white precipitate will be obtained if we add common salt solution to: (a) Ba(NO3)2solution (b) KNO3 solution (c)AgNO3solution (d) Mg(NO3)2 solution
Option (c) is the answer. A white precipitate is formed when we add common salt to silver nitrate which is a precipitation reaction.
- ChemistryClass 10ICSE
A white precipitate can be obtained by adding sulphuric acid to: (a) CuSO4 solution (b) NaCl solution (c) BaCl2 solution Na2SO4 solution
Option (c) is the answer. When dilute sulphuric acid reacts with the barium chloride then the barium sulphate is formed as a product with hydrochloric gas and thus formed barium sulphate will be white precipitate which is insoluble.
- ChemistryClass 10ICSE
In order to prevent the spoilage of potato chips, they are packed in plastic bags in an atmosphere of: (a) Cl2 (b)H2 (c)N2 (d) O2
Option (c) is the answer. If food items are packed in plastic bags in an atmosphere of nitrogen gas it does not spoil as nitrogen is an inert gas and does not react with the things. This is done to prevent the oxidation of fatty acids and oils present in the chips
- ChemistryClass 10ICSE
The term used to indicate the development of unpleasant smell and taste in fat and oil containing food due to aerial oxidation is: (a) Acidity (b)Radioactivity (c)Rabidity (d)Rancidity
Option (d) is the answer. Rancidity is the term used to indicate the development of unpleasant smell and taste in fat and oil containing food due to aerial oxidation and it can be prevented by closely and tight packing of food items in a container which does not allows air to react.
- ChemistryClass 10ICSE
The chemical reaction involved in the corrosion of iron metal is that of: (a) Oxidation as well as displacement (b) Reduction as well as combination (c) Oxidation as well as combination Reduction as well as displacement
Option (c) is the answer. Corrosion takes place when iron metal reacts with water and oxygen and form hydrated oxide and is an oxidation reaction as it is adding up of oxygen Iron metal combines with water and oxygen to corrode thus it is a combination reaction which further forms a single compound.