Question

Please help me sone question answer

Answer 1

Ans 1 (a) :- 293 K = 293 - 273 = 20°C

(b) :- 470 K = 470 - 273 = 197°C

Ans 2 (a) :- 25°C = 25 + 273 = 298K

(b) :- 373°C = 373 + 273 = 646K .

Ans 3 (a) :- This is because naphthalene sublimes I.e. it directly change into vapour without melting .

(b) :- This is because the molecules of perfume are moving with very high velocities ( diffusion ) in all the direction .

Ans 4 :- The increasing order of intermolecular forces of attraction is Oxygen < Water < Sugar .

Ans 5 (a) :- At 25°C , water is liquid .

(b) :- At 0°C , water is solid ( ice ) .

(c) :- At 100°C , water is Vapour ( Steam ) .

Ans 6 (a) :- At room temperature water is liquid because the attractive forces between the molecules of water are small and can move from one point to another .

(b) :- An iron almirah is solid because the molecules are held together by strong intermolecular attractive forces and the molecules or particles are very close to each other .

Ans 7 :- Ice at 273 K is more effective in cooling than water at the same temperature because in ice , the molecules have lower energy as compared to the particles in the liquid water at the same temperature ( 273 K ) and require latent heat of fusion for melting .

Ans 8 :- Steam produces severe burnsas compared to boiling water . This is because in steam the molecules have higher kinetic energy than in boiling water .

Ans 9 :- Show the diagram first then I will answer .