Chemistry
Select the correct answer from the choice in bracket to complete each sentence.
Nitrogen of the air is utilized by plants for formation of …………… [carbohydrates/proteins]
The gas evolved as a product of combustion as well as respiration is ……………[nitrogen dioxide / carbon dioxide].
A candle burns in a jar of oxygen, but gets extinguished in …………… [chlorine/nitrogen]
Air has variable composition and hence there is …………… [less/more] oxygen at lower altitudes than at higher altitudes.
Rusting is a chemical reaction which involves …………… [rapid/slow] oxidation.
Answer
Nitrogen of the air is utilized by plants for formation of proteins.
The gas evolved as a product of combustion as well as respiration is carbon dioxide
A candle burns in a jar of oxygen, but gets extinguished in nitrogen.
Air has variable composition and hence there is more oxygen at lower altitudes than at higher altitudes.
Rusting is a chemical reaction which involves slow oxidation.
Related Questions
Draw a neat labelled diagram to study the presence of carbon dioxide in air.
Name the following:
The product formed on oxidation of phosphorus.
The acid formed when the above product of oxidation of phosphorus, reacts with water.
The chemical name of rust.
The pollutant which combines with water vapour to give sulphuric acid – a product of acid rain.
The gas required for both combustion and rusting.
Give reasons for the following:
Acid rain has caused damage to heritage structures such as the Taj Mahal.
In the laboratory preparation of oxygen from potassium chlorate – manganese dioxide is added to the reactant.
Oxygen gas does not affect moist blue litmus paper, but carbon dioxide turns it slightly pink.
Oxidation of sulphur results in a product which turns moist blue litmus red.
Combustion and respiration show similarity.
Draw a neat labelled diagram to determine the component of air used up in burning, by using phosphorus and a bell jar.