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प्रश्न
Give a word equation for the following reaction.
A compound which on heating shows – colour change from brown to yellow.
उत्तर
Lead dioxide →Lead oxide + Oxygen
2Pb02 → 2PbO + 02 (l)
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संबंधित प्रश्न
When carbon dioxide is passed through lime water, it turns milky due to the formation of ______.
Changes in which new substances are formed are called ______ changes.
Complete and balance the following chemical equations:
`"H"_2"S"` + `"CI"_2` `→`
Complete and balance the following chemical equations:
Ba`"CI"_2` + `"H"_2"SO"_4` `→`
(aq.) (aq.)
What do you observe when Iron nail is kept in copper sulphate solution for sometime.
Define chemical reaction.
Copper carbonate when heated, it turns :
Explain the term reactant and product giving examples.
Give an example of a reaction where the following are involved:
Close contact
State the type of reactions for the following represent and balance the ones that are not balanced.
NaOH + HCl → NaCl + H2O
What is a chemical change? Give two examples of chemical change?
Complete and balance the following reaction:
\[\ce{Pb(NO3)2 ->[\Delta]}\]
Complete the following table and write your observations.
|
Hydrogen sulphide |
Ammonia |
Sulphur dioxide |
Hydrogen chloride |
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Shake the gas with red litmus solution |
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Shake the gas with blue litmus solution |
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Apply a burning splint to a gas |
Name: Two nitrates that do not produce nitrogen dioxide on heating.
Give a chemical test to distinguish between the following gases.
NH3 and HCl
Distinguish by heating the following in dry test tubs.
Copper Sulphate and copper carbonate
Select the correct answer for the following options:
The gas obtained when potassium chlorate is heated in the presence of a catalyst.
Give balanced equation for the following conversion affected by heat alone on the substance:
Zinc nitrate to nitrogen dioxide
State the following reaction represent oxidation or reduction.
\[\ce{Al->Al+++}\]
Complete the statement by filling in the blank with the correct word:
The reddish-brown precipitate obtained during a double decomposition precipitation reaction between an iron salt and alkali is __________.
_____ is the basic material to manufacture urea.
When an aqueous solution of potassium chloride is added to an aqueous solution of silver nitrate, a white precipitate is formed. Give the chemical equation of this reaction.
Write some materials prepared by chemical changes.
Which of the following statement is incorrect for a chemical reaction?
Classify the following processes into physical or chemical changes:
(i) Beating of aluminium metal to make aluminium foil.
(ii) Digestion of food.
(iii) Cutting of a log of wood into pieces.
(iv) Burning of crackers.
A student took a solution of copper sulphate in a beaker and put a clean iron nail into it and left it for about an hour.
What changes do you expect?
When magnesium is burnt in the air, a new substance is formed which is ______.
Magnesium + oxygen → magnesium oxide.
2Mg + O2 → 2Mg O
Why is spoiling food a chemical change?
