Questions for 2-10-2007

1. In an insulated vessel, 0.05 kg steam at 373 K and 0.45 kg of ice at 253 K are mixed. Then, find the final temperature of the mixture.

Given, L(fusion) = 80 cal/g = 336 J/g, L(vaporization) = 540 cal/g = 2268 J/g,
S(ice) = 2100 J/kg K = 0.5 cal/gK and S(water) = 4200 J/kg K = 1 cal /gK

2. If f″(x) = − f(x) and g(x) = f′(x) and F(x) = [f(x/2)]^2 + [g(x/2)]^2 and given that F(5) = 5 then F(10) is equal to

(A) 5
(B) 10
(C) 0
(D) 15



3. The edge length of unit cell of a metal having molecular weight 75 g/mol is 5
A^0 which crystallizes in cubic lattice. If the density is 2 g/cc then find the radius of metal atom. [N(A) = 6 × 10^23]. Give the answer in pm.