Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

Some Basic Concepts of Chemistry

Short Answer Type

191.

How many litres of oxygen at S.T.P. will be required to burn completely 2.2 g of propane?

236 Views

192.

Calculate the amount of KClO₃needed to supply sufficient oxygen for burning 112L CO gas at S.T.P.

262 Views

193.

How many moles of oxygen can be obtained by the decomposition of 1 mole of potassium chlorate in the following reaction:

$2 KClO subscript 3 left parenthesis straight s right parenthesis space rightwards arrow space space space 2 KCl left parenthesis straight s right parenthesis space plus 3 straight O subscript 2 left parenthesis straight g right parenthesis$

How many moles of reactants are needed for obtaining 1 mole of oxygen?

107 Views

194.

Gastric juice contains 3g HCl per litre. If a person produces 2.5 L of gastric juice per day, how many antacid tablets each containing 400 mg of Al(OH)₃ are needed to neutralise all the HCl produced in one day?

303 Views

Long Answer Type

195.

Calculate the quantity of lime required to soften 60000 litres of well water containing 16.2 g of calcium carbonate per hundred litre.

168 Views

Short Answer Type

196. KBr (potassium bromide) contains 32·9% by weight of potassium. If 6·40 g of bromine reacts with 3·60 g of potassium, calculate the number of moles of potassium which combines with bromine to form KBr.

140 Views

197. Decomposition of NaHCO₃ takes place at 270°C. In a sample containing Na₂CO₃ and NaHCO₃, the heating at 270°C results in the loss of 10% by weight. What is the percentage composition of the sample?

95 Views

198.

How much potassium chlorate should be heated to produce 2.24 L of oxygen at NTP?

327 Views

199.

If ten volumes of dihydrogen gas react with five volumes of dioxygen gas, how many volumes of water vapour could be produced?

124 Views

Long Answer Type

200.
What volume of oxygen at STP is required to affect complete combustion of 200 cm³ of acetylene and what would be the volume of carbondioxide formed?

The chemical equation representing the combustion of acetylene is

(i) To calculate the volume of O₂ at STP required to effect complete combustion of 200 cm3of acetylene:
According to Gay Lussac’s law of gaseous volumes,
2 volumes C₂H₂ will require O₂ for complete combustion = 5 vol

200 cm³ C₂H₂ will require O₂ for complete combustion =

= 500 cm³ at STP
Thus volume of O₂ required = 500 cm³ at S.T.P.

(ii) To calculate the volume of CO₂ produced at S.T.P
According to Gay Lussac’s law of gaseous volumes.
2 volumes of C₂H₂ produce CO₂ = 4 vol