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प्रश्न
Circle the odd one out. Give reason for your choice
विकल्प
Growth of a child
Blinking of eye
Rusting
Germination of a seed
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उत्तर
Rusting
Reason: Rusting is undesirable change. Others three are desirable changes.
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संबंधित प्रश्न
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.
Reduction is a chemical reaction in which there is
- removal of hydrogen
- removal of oxygen
- addition of oxygen
- none of these
TRUE \ FALSE
The evolution of a gas during a chemical reaction is shown by an arrow pointing downwards. True or false ?
Is kerosene an electrolyte or a non-electrolyte ?
How is a strong electrolyte different from a weak electrolyte?
Define chemical reaction.
Write true or false :
When iron and sulphur are heated together a grey mass is formed which is attracted by a magnet .
Write true or false.
A chemical equation gives only qualitative information of a chemical reaction.
What is the reaction called when oxidation and reduction take place simultaneously? Explain with one example.
Explain the term reactant and product giving examples.
Multiple choice:
A reaction of a type: AB + CD → AD + CD, involves
Name: A greenish-yellow gas.
Name: Two nitrates that do not produce nitrogen dioxide on heating.
What do you observe when CO2 is passed through lime water first and then a little in excess.
Give reason for the following:
The catalytic oxidation of sulphur dioxide to sulphur trioxide is represented by a double arrow {⇌}
between the reactants and products, formed in the chemical reaction.
Complete the table given below.
| Addition of dil. H2SO4 to KHCO3 | Name of residue obtained |
Chemists identify gypsum as a natural indicator.
Classify each of the following, as a physical or a chemical change. Give reasons.
(a) Drying of a shirt in the sun.
(b) Rising of hot air over a radiator.
(c) Burning of kerosene in a lantern.
(d) Change the colour of black tea by adding lemon juice to it.
(e) Churning of milk cream to get butter.
Iron benches kept in lawns and gardens get____________. It is a _________ change because a new _________ is formed.
Galvanization is a process in which ______ is coated as a layer of iron.
