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प्रश्न
Write one equation for decomposition reactions where energy is supplied in the form of electricity.
उत्तर
Decomposition reaction involving absorption of electrical energy,
- \[\ce{\underset{Alumina}{2Al2O3_{(l)}} ->[Electric current] \underset{Aluminium}{4Al_{(l)}} + \underset{Oxygen}{3O2_{(g)}}}\]
- \[\ce{2H2O_{(l)} ->[electricity] 2H2_{(g)} + O2_{(g)}}\]
संबंधित प्रश्न
Taking into consideration the relationship in the first pair, complete the second pair
2H2 + O2 → 2H2O :Combination Reaction :: 2HgO → 2Hg + O2:_________
The white solid compound A decomposes quite rapidly on heating in the presence of a black substance X to form a solid compound B and a gas C. When an aqueous solution of compound B is reacted with silver nitrate solution, then a white precipitate of silver chloride is obtained along with potassium nitrate solution. Gas C does not burn itself but helps burn other things.
(a) What is compound A?
(b) What is compound B?
(c) What is gas C?
(d) What do you think is the black substance X? What is its function?
(e) What is the general name of substances like X?
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 alongwith 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 alongwith 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?
(e) Write the name and formula of the salt which turns the solution green in the first case.
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?
Classify the following reaction as combination, decomposition, displacement, precipitation and neutralization. Also balance the equation.
\[\ce{Zn_{(s)} + H2SO4 -> ZnSO4_{(s)} + H2_{(g)}}\]
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Thermal decomposition of a substance is brought about with the help of
- reactants
- water
- wind
- heat
Give scientific reason.
When the gas formed on heating limestone, is passed through freshly prepared lime water, the lime water turns milky.
How can the rate of the chemical reaction, namely, decomposition of hydrogen peroxide be increased?
Give a balanced equation for –
An electrolytic decomposition reaction involving a neutral liquid
Give a balanced equation for –
A white precipitate obtained during a double decomposition reaction involving a silver salt with sodium salt.
Differentiate between the following:
Thermal decomposition and thermal dissociation.
Differentiate between the following:
Electrolytic decomposition and photochemical decomposition.
Electrolysis is type of ______ reaction.
Chemical volcano is an example of ______ type of reaction.
The following reaction is used for the preparation of oxygen gas in the laboratory:
\[\ce{2KClO3_{(s)} ->[Heat] 2KCl + 3O2_{(g)}}\]
Which of the following statement about the reaction is correct?
Give the ratio in which hydrogen and oxygen are present in water by volume.
What is observed when silver chloride is exposed to sunlight? Give the type of reaction involved.
Write the molecular formula of calcium carbonate.
