CLASS 11 CHAP1 &2

Which is not a unit of pressure:

• (a) Bar

• (b) N/m²

• (c) Kg/m²

• (d) Torr

The number of moles present in 6 gms of carbon is:

• (a) 2

• (b) 0.5

• (c) 5

• (d) 1

Which of the following weighs the most?

• (a) One g – atom of nitrogen

• (b) One mole of water

• (c) One mole of sodium

• (d) One molecule of H2SO4

An organic compound contains carbon , hydrogen and oxygen. Its elemental analysis gave C, 38.71% and H, 9.67%. The empirical formula of the compound would be

• (a) CHO

• (b) CH4O

• (c) CH3O

• (d) CH2O

Which of the following contains same number of carbon atoms as are in 6.0 g of carbon (C – 12)?

• (a) 6.0 g Ethane

• (b) 8.0 g Methane

• (c) 21.0 g Propane

• (d) 28.0 g CO

a given principal level n = 4, the energy of its subshells is in the order

• (a) s < p < d < f

• (b) s > p > d > f

• (c) s < p < f < d

• (d) f < p < d < s

Which of the following statements in relation to the hydrogen atom is correct?

• (a) 3s orbital is lower in energy than 3p orbital

• (b) 3p orbital is lower in energy than 3d orbital

• (c) 3s and 3p orbitals are of lower energy than 3d orbital

• (d) 3s, 3p and 3d orbitals all have the same energy

A body of mass 10 mg is moving with a velocity of 100 ms-1. The wavelength of de-Broglie wave associated with it would be (Note: h = 6.63 × 10-34 Js)

• (a) 6.63 × 10-37 m

• (b) 6.63 × 10-31 m

• (c) 6.63 × 10-34 m

• (d) 6.63 × 10-35 m

The ionization enthalpy of hydrogen atom is 1.312 × 106 J mol-1. The energy required to excite the electron in the atom from n = 1 to n = 2 is

• (a) 8.51 × 105 J mol-1

• (b) 6.56 × 105 J mol-1

• (c) 7.56 × 105 J mol-1

• (d) 9.84 × 105 J mol-1

Which of the following statements does not form a part of Bohrs model of hydrogen atom?

• (a) Energy of the electrons in the orbit is quantised

• (b) The electron in the orbit nearest the nucleus has the lowest energy

• (c) Electrons revolve in different orbits around the nucleus

• (d) The position and velocity of the electrons in the orbit cannot be determined simultaneously