Chemistry

Chemistry

1. The number of electrons present on the oil drop which has the static electric charge of -3.02044×10-19 C is

  1. 2
  2. 5
  3. 7
  4. 8

Correct answer: (A)
2

2. Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 4000 A0. The threshold frequency is

  1. 5×1034 sec-1
  2. 7.5×1014 sec-1
  3. 9.2×1014 sec-1
  4. 7.5×1034 sec-1

Correct answer: (B)
7.5×1014 sec-1

3. An element Z=120 has not yet been discovered. In which group would you place this element

  1. IV A
  2. VII A
  3. II A
  4. V A

Correct answer: (C)
II A

4. The correct matching is

  1. IE1 : Rb > K > Na
  2. Radius : I+< I > I-
  3. E.N : F < Cl < Br
  4. EA : S > Se > O

Correct answer: (D)
EA : S > Se > O

5. In a molecule of type (AB2L3) , the central atom (A) contains two bond pairs (B) and three lone pairs(L) . Then the shape of that molecule is

  1. T-shape
  2. See saw
  3. V-shape
  4. Linear

Correct answer: (D)
Linear

6. At a given temperature, the ratio of Kinetic energy of 3 gram of hydrogen and 4 gram of oxygen is

  1. 1:12
  2. 12:1
  3. 5:6
  4. 3:4

Correct answer: (B)
12:1

7. The prefix ‘pico’ represents the multiple of

  1. 10-9
  2. 10-12
  3. 10-18
  4. 10-21

Correct answer: (B)
10-12

8. The specific gravity of 84% (w⁄w) H2 SO4 is 1.752. The normality of solution is

  1. 30.03 N
  2. 2.05N
  3. 39.5N
  4. 4.5N

Correct answer: (A)
30.03 N

9. The Oxidation State of Fe in [Fe(H2O)5NO]+2 (Brown ring) is

  1. +1
  2. +2
  3. +3
  4. +6

Correct answer: (A)
+1

10. Identify the salt whose aqueous solution is basic

  1. NH4Cl
  2. CuSO 4
  3. Al2(SO4)3
  4. KCN

Correct answer: (D)
KCN