NDA CHEMISTRY PAST QUESTION ’15

 

1. The apparatus used in the industrial separation of crude oil into its various fractions
A. Lieber condenser
B. Delivery Tower
C. Petroleum Tower
D. Fractionating tower

2. Which of the following statements is not correct about group VII elements? They are
A. diatomic
B. with relatively low ionizing potential
C. have a high electron affinity
D. good oxidizing agents

3. Which of the following molecules has two lone pairs of electrons and is 5P3hybridised?
A. NH3
B. C6H6
C. H2O
D. CO2

4. What is the half-life of a radioactive nuclide whose decay constant is 0.0522yr-1
A. 0.03 yr
B. 0.30 Yr
C. 0.70 Yr
D. 13.30 Yr

5. In the reaction 4NH3(g) + 5O2(g) ⟶ 4NO(g) + 6H2O, 1.0mol of ammonia and 1.0mol of oxygen are made to react. Therefore,
A. 1.0 mol of H2O will be produced
B. 1.0 mol of NO will be produced
C. all the ammonia will be consumed
D. oxygen will be the limiting factor

6. Steam changes the colour of anhydrous cobalt (II) chloride from
A. blue to pink
B. white to blue
C. white to red
D. blue to white

7. The electronic configuration of excited carbon atom is
A. 1S22S22Px12Py1
B. 1S22S22Px12Py12Pz1
C. 1S22S22P2
D. 1S22S12P4

8. For the reaction: 2H+ + Zn ⟶ H2 + Zn2+
∆G = —147KJmol. What is the corresponding value of E° cell?
A. 1.52V
B. —0.76V
C. 0.76V
D. —1.52V

9. The atomic number of Iron is 26. What is the number of unpaired electrons in Fe3+1
A. 5
B. 4
C. 3
D. 2

10. Baking soda and hydrochloric acid react according to the following equation:
NaHCO3(aq) + HCl(aq) NaCl(aq) + CO2(g) + H2O(g) Calculate the mass of baking soda (NaHCO3) that would produce 10.0g of carbon (IV) oxide [Cl = 35.5, Na 23.0 O = 16, C = 12 H = 1]
A. 19.0g
B. 38.0g
C. 190.0g
D. 320.0g

11. What is the main gas found in the air we breathe?
A. Oxygen
B. Carbon dioxide
C. Nitrogen
D. Methane

12. What is the first most abundant element in the universe in terms of mars
A. Carbon
B. Hydrogen
C. Oxygen
D. Copper

13 The most common bleaching agent is?
A. Alcohol
B. Carbon dioxide
C. Chlorine
D Caustic soda

14. The law which states that the amount of gas dissolved in a liquid is proportional to its partial pressure is’?
A. Dalton’s law
B. Gay Lussac’s law
C. Henry’s Law
D. Raoult’s Law

15. Which is the chemical formula for Iron (III) sulphate
A. Fe2SO4
B. Fe3SO4
C. Fe(SO4)3
D. Fe2(SO4)3

16. NH4Cl(s)  NH3(g) + HCl(g)
The reaction above can only attain equilibrium if?
A. It is in a closed system
B. It is in an open system
C. a gaseous reactant is added
D. one of the product is removed

17. For elements in the left-most column of the Periodic Table, properties that have increasing values as the atomic number increases, include which of the following?
I
Ionization Energy (Potential)
II
Atomic radius
III
Atomic mass

A. I only
B. III only
C. I and II only
D. II and III only

18. The number of oxygen atoms in 0.50 Mole of KHSO4 is
A. 1.2 X 1023
B. 2.4 x 1024
C. 3.0 x 1023
D. 1.2 x 1024

19. Which of the following is not a separation technique?
A. Sieving
B. Dissolution
C. Filtration
D. Floatation

20. An increase in the rate of a chemical reaction on heating is due to an increase in
A. Entropy
B. Enthalpy
C. Collision rate
D. Reactant concentration

Check your questions 21 – 40 here

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