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प्रश्न
NPK are the primary nutrients for plants.
विकल्प
True
False
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उत्तर
NPK are the primary nutrients for plants- True.
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संबंधित प्रश्न
When carbon dioxide is passed through lime water, it turns milky due to the formation of ______.
What are (i) positive catalysts and (ii) negative catalysts? Support your answer with one example for each of them.
FILL IN THE BLANK
A .............. change is a temporary change.
FILL IN THE BLANK
In a double decomposition precipitation reaction both the reactants must be ............ soluble.
FILL IN THE BLANK
In a ............ change, new substances are formed.
What are homogenous reactions ?
State four conditions necessary for chemical reactions to take place.
A solution of a substance ‘X’ is used for white washing Name the substance ‘X’ and write its formula.
Give an example of a reaction where the following are involved:
Close contact
Complete and balance the following reaction:
NaCl(aq) + AgNO3(aq) →
What is observed in performing the following :
| Hydrogen | Oxygen | Carbon dioxide | Chlorine | |
| Litmus test | ||||
| Apply a burning splint to the gas | ||||
| Colour of gas | colourless | colourless | colourless | greenish-yellow |
| Odour of gas |
Write your observation and a balanced equation in the case of the following substances being heated.
Copper carbonate.
Give examples of exothermic reactions i.e. heat evolved in each of the following:
(a) reaction between a solid and a liquid
(b) reaction between two gases
Give two examples of exothermic reactions seen in everyday life.
Give a balanced equation for the conversion of an ammonium salt to a basic gas.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Calcium hydroxide.
Silver articles turning black: ______:: Boiling of H2O: physical change ______.
Burning of paper is the best example of ______ change.
Chemists identify gypsum as a natural indicator.
We are advised to not to play with fireworks. Give reason.
Acid rain is a result of ______.
