Model Paper 5 — Chemistry STD 11 Science — Question

Explain the deviation in ionisation enthalpy of some elements from the general trend by using.

The amount of energy released when 1 × 10¹⁰ atoms of chlorine in vapour state are converted to Cl^- ions according to the equation,
Cl(g) + e^- → Cl^-(g) is 57.86 × 10^-10J
Calculate the electron gain enthalpy of chlorine atom in terms of kJ mol^-1 and eV per atom.

1. Classify the following processes as reversible or irreversible:

1. Dissolution of sodium chloride.
2. Evaporation of water at 373K and 1atm pressure.
3. Mixing of two gases by diffusion.
4. Melting of ice without rise in temperature.

2. When an ideal gas expands in vacuum, there is neither absorption nor evolution of heat. Why?

Give two similarities and one difference between Boron and Aluminium.

A 0.02M solution of pyridinium hydrochloride has pH = 3.44. Calculate the inoisation constant of pyridine.

Calculate the amount of carbon dioxide that could be produced when
(i) 1 mole of carbon is burnt in air.
(ii) 1 mole of carbon is burnt is 16 g of dioxygen.
(iii) 2 moles of carbon are burnt in 16 g of dioxygen.

2 Arrange the following set of compounds in order of their decreasing relative reactivity with an electrophile, E⁺.
Chlorobenzene, 2,4-dinitrochlorobenzene, p-nitrochlorobenzene.

Calculate the wavelength of tennis ball of mass 60 gram moving with a velocity of 10ms^-1. (h = 6.626 × 10^-34Js)