HSC Science Class 11 - Tamil Nadu Board of Secondary Education Question Bank Solutions for Chemistry

Define the calorific value of food.

What is the unit of calorific value?

Which one of the following binary liquid mixtures exhibits positive deviation from Raoults law?

At 100°C the vapour pressure of a solution containing 6.5 g a solute in 100 g water is 732 mm. If K_b = 0.52, the boiling point of this solution will be ______.

According to Raoults law, the relative lowering of vapour pressure for a solution is equal to ______.

The relative lowering of vapour pressure of a sugar solution in water is 2.5 × 10^-3. The mole fraction of water in that solution is ______.

Which of the following aqueous solutions has the highest boiling point?

Explain how heat absorbed at constant volume is measured using a bomb calorimeter with a neat diagram.

The vapour pressure of pure benzene (C₆H₆) at a given temperature is 640 mm Hg. 2.2 g of non – volatile solute is added to 40 g of benzene. The vapour pressure of the solution is 600 mm Hg. Calculate the molar mass of the solute?

In a constant volume calorimeter, 3.5 g of gas with molecular weight 28 was burnt in excess oxygen at 298 K. The temperature of the calorimeter was found to increase from 298 K to 298.45 K due to the combustion process. Given that the calorimeter constant is 2.5 kJ K⁻¹. Calculate the enthalpy of combustion of the gas in kJ mol⁻¹.

Calculate the standard heat of formation of propane, if its heat of combustion is −2220.2 kJ mol⁻¹ the heats of formation of \[\ce{CO2_{(g)}}\] and \[\ce{H2O_{(l)}}\] are −393.5 and −285.8 kJ mol⁻¹ respectively.

A gas mixture of 3.67 lit of ethylene and methane on complete combustion at 25°C and at 1 atm pressure produce 6.11 lit of carbon dioxide. Find out the amount of heat evolved in kJ, during this combustion. (ΔH_C(CH₄)) = − 890 kJ mol⁻¹ and (ΔH_C(C₂H₄)) = − 1423 kJ mol⁻¹

A sample of 0.5 g of an organic compound was treated according to Kjeldahl’s method. The ammonia evolved was absorbed in 50mL of 0.5 M H₂SO₄ The remaining acid after neutralization by ammonia consumed 80 mL of 0.5 M NaOH. The percentage of nitrogen in the organic compound is.

In an organic compound, phosphorus is estimated as ______.

Give the principle involved in the estimation of halogen in an organic compound by Carius method.

0.30 g of a substance gives 0.88 g of carbon dioxide and 0.54 g of water calculate the percentage of carbon and hydrogen in it.

The ammonia evolved form 0.20 g of an organic compound by Kjeldahl method neutralized 15 ml of N/20 sulphuric acid solution. Calculate the percentage of Nitrogen.

0.32 g of an organic compound, after heating with fuming nitric acid and barium nitrate crystals is a sealed tube game 0.466 g of barium sulphate. Determine the percentage of sulphur in the compound.

0.24g of an organic compound gave 0.287 g of silver chloride in the carius method. Calculate the percentage of chlorine in the compound.

In the estimation of nitrogen present in an organic compound by Dumas method 0.35 g yielded 20.7 mL of nitrogen at 15° C and 760 mm pressure. Calculate the percentage of nitrogen in the compound.