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प्रश्न
NPK are the primary nutrients for plants.
विकल्प
True
False
उत्तर
NPK are the primary nutrients for plants- True.
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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.
Reduction reaction is the exact opposite of
- displacement reaction
- decomposition reaction
- oxidation reaction
- none of these
What are the characteristics of a chemical reaction ? A chemical reaction is characterised by an irreversible change in which a new substance is formed.
Fill in the blank
A new substance is always formed in a _______ change.
Fill in the blank:
In some chemical reactions an insoluble ________ is formed when two solutions are mixed.
State what you would observe when the following substance is heated in a glass test tube red lead.
State what you would observe when the following substance is heated in a glass test tube Copper (II) carbonate Red lead .
Give an example of a reaction where the following are involved
Electricity
Give an example of a reaction where the following are involved:
Close contact
Give an example of a reaction where the following are involved:
Solution
What do you observe? When
Water is added to the quick lime.
Complete and balance the following reaction:
\[\ce{CuCO3 ->[\Delta]}\]
Distinguish by heating the following in dry test tubs.
Zinc nitrate and copper nitrate.
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.
Water boiling into water vapour is an example of chemical change.
Which of the following are chemical changes?
(i) Decaying of wood
(ii) Burning of wood
(iii) Sawing of wood
(iv) Hammering of a nail into a piece of wood
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.
Vanaspati is obtained from vegetable oils by the addition of ______ to the oils.
Assertion (A): Cutting paper into very small pieces is an irreversible change.
Reason (R): Physical changes are always reversible.
The reaction of H2 gas with oxygen gas to form water is an example of ______.
