Question

Ε) Η - Give the set of four quantum numbers that could represent the last electron added (using the Aufbau principle) to the Sn atom. A) n=5,1 = 0, m=0, m = -1 B) n = 4,1 = 1, mi= -1, ms = + 12 C) n=5,1 = 1, mi=+1, m. = +12 D) n = 4,1 = 1, m= -1 m. =-12 E) n=5,1-0, mi-1, m. =+14 16) Which of the following sets of elements is arranged in the correct order of decreasing first ionization energy (IE:)? A) CI > Br>I B) Rb > K> Ca C) K> Na > Li D) As >S>F E) Sb > Te>I 17) Calculate the work, w, gained or lost by a gaseous system as it expands from 15 L to 50 L against a constant external pressure of 1.5 atm. (1 L atm = 101.3 J) A) -5.3 kJ B) +7.6 kJ C) -7.6 kJ D) +5.3 kJ 18) of the following, which has the longest de Broglie wavelength? A) a nitrogen molecule moving at a velocity of 1000 mph B) a nitrogen molecule moving at a velocity of 5000 mph

Answer 1

(15) Atomic No. of Sn = 50 Electronic Configuration [ko] 4 d 58² 5p² .. last election is in 5p . .n=5 and l=1 Correct option will be c' Correct option is 'A' because as we move down the group in periodic table size increases due to which ronization energy decreases - cd > Br> I (IE) - work, w = - Pext or =-1.5 (50-15) = -1.5x35 = -52.5 L-atom .. 1 L-atm = 101. 3J : - 52.5 L-atm = -5318.25 J - 5.31825 KJ option al

DATE B de Broglie wavelength , ad = h P = linear momentum h = planck's constant p=mv m = mass va velocity 2. - the molecule which has lower velocity will have longest velocity provided mass is same. . Option A is correct