NEET Practice Questions (MCQs) with Answers & Solutions

(d) Root mean square velocity at T₁ temperature,

              U₁ = $\sqrt{\frac{3R{T}_1}{M}}=\sqrt{\frac{3R(27+273)}{M}}$            .....(i)

    Root mean square velocity at T₂ temperature,

             U₂ = $\sqrt{\frac{3R{T}_2}{M}}=\sqrt{\frac{3R(927+273)}{M}}$           ......(ii)

      Eq. (i) divided by Eq. (ii)

             U₁/U₂ = $\sqrt{\frac{27 +273}{927 + 273}}$= $\sqrt{\frac{300}{1200}}$=1/2

                  U₂ = 2U₁

(b) Initial volume, V₁ = 500 mL

Initial temperature,

              T₁ = 27$°$C = 27 + 273 = 300 K

Final temperature,

             T₂ = -5 + 273 = 268 K

             V₂ = ?

             V₁/T₁ = V₂/T₂

             V₂ = V₁T₂/T₁ = (500 x 268)/300 = 446.66 mL

(c) Ideal gas cannot be liquefied as its molecules have no forces of attractions.

(d) The average velocity of gas molecules in one direction is zero otherwise all molecules will be collected in one direction.

(c) H₂ and He possess minimum molar mass among all gases.

(a) Increase of pressure decreases volume and molecules come closer to each other.

(d) CO reacts with red colouring heamoglobin molecules in blood to form a complex of cherry red colour.

(c) For ideal gases PV = nRT, .^.. Z =1; because Z = PV/nRT

(b) The numerical value of R depends upon the units in which pressure and volume are expressed. When pressure is expressed in atmosphere and volume in litres, then the value of R at STP for 1 mole of gas is R = (1 atm x 22.414 L/1 mole x 272.15 K)  = 0.082 L atm K^-1 mol^-1