(a) White silver chloride turns grey in sunlight:
- Silver chloride (AgCl) decomposes when exposed to sunlight, forming silver (Ag) and chlorine gas (Cl₂). The silver particles are grey, which causes the white silver chloride to turn grey. The reaction is: 2AgCl→2Ag+Cl2
(b) Brown-colored copper powder turns black when heated in the air:
- When copper (Cu) is heated in air, it reacts with oxygen (O₂) to form copper(II) oxide (CuO), which is black. This is an oxidation reaction. The reaction is: 2Cu+O2→2CuO2
Other Related Questions For Practicing Before the Exam
- MCQ Test for Chemical Reactions and Equations Class 10
- Support MCQs Answer: Chemical Reactions and Equations Class 10
- Give an example of a double displacement reaction
- Name reducing agent in the given chemical reaction: 3MnO2 + 4Al → 3Mn + 2Al2O3
- Name the brown coloured gas evolved when lead nitrate crystals are heated in a dry test-tube
- Give reasons: Silver chloride is stored in dark-colored bottles.
- What changes do you observe in iron nails and the color of the copper sulphate solution if iron nails are dipped in CuSO₄ solution for some time?
- Identify the chemical change: Melting of ice or conversion of milk into curd.
- Why is respiration considered an exothermic reaction?
- Why do copper vessels lose shine when exposed to air?
- Potato chips manufacturers fill the packet of chips with nitrogen gas. Why?
- Why do we store silver chloride in dark coloured bottles in labs?
- Write chemical equations of a double displacement reaction
- N₂ + 3H₂ → 2NH₃, name the type of reaction.
- What happens when milk is left open at room temperature during summer?
- What happens when quicklime is added to water?
- Define combination reaction. Give two examples of combination reactions which are exothermic in nature.
- What is decomposition reaction? Explain with the help of an example.
- Name and state the law which is kept in mind when we balance a chemical equation
- Give one example of each: (a) Chemical reaction showing evolution of gas:
- What is rancidity? Write two ways by which it can be prevented.
- What are two conditions which promote corrosion?
- A small amount of Ferrous sulphate is heated in hard glass tube.
- What happens when Zn strip is dipped in CuSO2 solution?
- What is a redox reaction? Write down a chemical reaction representing it.
- In electrolysis of water: Name the gas collected at cathode and anode
- In the reaction: CuO(s) + H2(g) → Cu(s) + H2O (g)
- Give reasons: (a) White silver chloride turns grey in sunlight
- Compound ‘X’ decomposes to form compound ‘Y’ and CO₂ gas. Compound Y is used in the manufacturing of cement.
- A metal salt MX, when exposed to light, splits up to form metal M and gas X₂. Metal M is used to make ornaments whereas gas X₂ is used in making bleaching powder. The salt MX is used in black & white photography.
- A metal strip X is dipped in a blue-colored salt solution YSO₄. After some time, a layer of metal ‘Y’ is formed on metal strip X. Metal X is used in galvanization whereas metal Y is used for making electric wires.
- When potassium iodide solution is added to a solution of lead nitrate in a test tube, a precipitate is formed. (CBSE-2015 Comptt)
- Decomposition reactions require energy either in the form of heat or light a electricity for breaking down of reactions. Write one equation for each type of decomposition reaction where heat, light or electricity is used as form of energy.
- 2 gm of silver chloride is taken in china dish, and china dish is placed in sunlight for sometime. What will be your observation. Write the balanced chemical equation for above reaction and identify the type of reaction.
- Identify the type of reactions taking place in each of the following cases and write the balanced chemical equation for the reactions. (a) Zn reacts with silver nitrate to produce zinc nitrate and silver:
- LONG ANSWER TYPE OF QUESTIONS (5 MARKS) Class 10 Supports Answers
