Advertisements
Advertisements
प्रश्न
Give one example each of which illustrates the following characteristics of a chemical reaction:
change of colour
उत्तर
When blue coloured copper sulphate reacts with hydrogen sulphide gas, a black coloured substance copper sulphide is formed.
\[\ce{\underset{\text{copper sulphate solution, blue}}{CuSO4} + \underset{\text{hydrogen sulphide}}{H2S} ->\underset{\text{copper sulphide black solid}}{CuS} +\underset{\text{sulphuric acid}}{H2SO4}}\]
APPEARS IN
संबंधित प्रश्न
A solution of a substance ‘X’ is used for white washing.
- Name the substance ‘X’ and write its formula.
- Write the reaction of the substance ‘X’ named in (i) above with water.
Write the balanced chemical equation for the following and identify the type of reaction.
\[\ce{Hydrogen(g) + Chlorine(g) -> Hydrogen chloride (g)}\]
A silvery-white metal X taken in the form of ribbon, when ignited, burns in air with a dazzling white flame to form a white powder Y. When water is added to powder Y, it dissolves partially to form another substance Z.
(a) What could metal X be?
(b) What is powder Y?
(c) With which substance metal X combines to form powder Y?
(d) What is substance Z? Name one domestic use of substance Z.
(e) Write a balanced chemical equation of the reaction which takes place when metal X burns in air to form powder Y.
Give one example of a combination reaction which is also exothermic.
Explain the terms with examples.
Combination reaction
State why a direct combination reaction is called a – ‘synthesis reaction’.
The number of products formed in a synthesis reaction is ______
The chemical reaction between copper and oxygen can be categorized as ______.
Balance the following chemical equation and identify the type of chemical reaction.
`"CaO"("s") + "SiO"_2("s") -> "CaSio"_3("s")`
A clear solution of slaked lime is made by dissolving Ca(OH)2 in an excess of water. This solution is left exposed to air. The solution slowly goes milky as a faint white precipitate forms. Explain why a faint white precipitate forms, support your response with the help of a chemical equation.
