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प्रश्न
Give reason for the following:
Electrolytic decomposition of water is a reaction involving change of state.
उत्तर
Electrolysis of water is the decomposition of water into hydrogen and oxygen due to the passage of electric current through it.
\[\ce{2H2O(l)->[Electric Current] 2H2 (g) + O2 (g)}\]
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संबंधित प्रश्न
What are (i) positive catalysts and (ii) negative catalysts? Support your answer with one example for each of them.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Which one of the following alters the rate of the chemical reaction without itself undergoing any change?
- temperature and Pressure
- concentration of reactants
- presence of catalyst
- none of these
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Compounds, which in their molten state allow an electric current to pass through them are called
- electrolytes
- non-electrolytes
- non-conductors
- none of these
FILL IN THE BLANK
Negatively charged ions are called ..........
FILL IN THE BLANK
Distillation is a method of obtaining pure ............. from a solution.
Fill in the blank:
The basic conditions necessary for a chemical reaction is _______
Write true or false :
When potassium iodide solution is added to lead acetate solution a red precipitate is formed.
Balancing a chemical equation is based on
Name the type of chemical reaction shown by the following equation:
NaOH + HCl → NaCl + H2O
Explain the term reactant and product giving examples.
Give an example of the following chemical change.
A reaction where colour change is noticed
Give reason for the following:
Colourless concentrated sulphuric acid in a test tube changes to blue on adding a small piece of copper to it.
When hydrogen burns in oxygen, water is formed; when electricity is passed through water, hydrogen and oxygen are given out. Name the type of chemical change involved in the two cases.
State the type of reactions for the following represent and balance the ones that are not balanced.
Cl2 + 2KBr → 2KCl + Br2
State the type of reactions for the following represent and balance the ones that are not balanced.
NaOH + HCl → NaCl + H2O
Name Affects the acidified K2Cr2O7 paper and also turns lime water dirty milky.
Name: Two carbonates do not produce carbon dioxide on heating.
Name: A brown gas
Give a chemical test to distinguish between the following gases.
HCl and H2S
Give a chemical test to distinguish between the following gases.
NH3 and HCl
Give a chemical test to distinguish between the following gases.
SO2 and Cl2
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper carbonate to copper oxide
Give two examples where a chemical reaction is accompanied by a change in colour of the reactants and products on completion of the reaction.
Differentiate between the following:
Neutralization reaction and a precipitation reaction.
Discuss how acid rain occurs due to emission of smoke from vehicles and industries?
Which of the following is not an “element + element → compound” type reaction?
Chemical change is a temporary change.
What is the use of indicator?
Give two examples for each of the following cases:
Chemical changes.
Heat may evolve or be absorbed during a ______ change.
