Which one of the following is called amphoteric solvent ?
Ammonium hydroxide
Chloroform
Benzene
Water
100 mL of 0.04 N HCl aqueous solution is mixed with 100 mL of 0.02 N NaOH solution. The pH of the resulting solution is
1.0
1.7
2.0
2.3
C.
2.0
Given,
Conc. of HCl = 0.4 N
Volume of HCl = 100 mL
Conc. of NaOH = 0.02 N
Volume of NaOH = 100 mL
pH = ?
Milli equivalents of HCl = 0.04 × 100 = 4
Milli equivalents of NaOH = 0.02 × 100 = 2
Total volume of solution = 100 mL + 100 mL = 200 mL
2 milliequivalents of HCl are present in 200 mL solution
10 milliequivalents of HCl are present in 1000 mL solution
Concentration of HCl =
HCl → H+ + Cl-
[H+] in solution = 0.01
0.01 N HCl = 0.01 M HCl ( HCl is monobasic)
pH = -log [H+]
= -log (0.01)
= 2
If a system is at equilibrium, the rate of forward to the reverse reaction is :
less
equal
high
at equilibrium
The equilibrium constant for the reaction N2(g) + O2(g) 2NO(g) is 4×10-4 at 200K. In presence of a catalyst the equilibrium is attained ten times faster. Therefore the equilibrium constant in presence of catalyst 2000 K is
4×10-3
4×10-2
40×10-4
4×10-4
At a given temperature the equilibrium constant for the reaction of:
PCl5 PCl3 + Cl2 is 2.4 × 10-3. At the same temperature, the equilibrium constant for the reaction
PCl3 (g) + Cl2 (g) PCl5 (g) is :
2.4 × 10-3
-2.4 × 10-3
4.2 × 102
4.8 × 10-2
For the gaseous reaction, C2H4 + H2 C2H6; H = -130 kJ mol-1 carried in a closed vessel, the equilibrium concentration of the C2H6 can definitely be increased by:
increasing temperature and decreasing pressure
decreasing temperature and increasing pressure
increasing temperature and pressure both
decreasing temperature and pressure both
Which of the following is correct for the reaction?
N2(g) + 3H2 (g) 2NH3 (g)
Kp = Kc
Kp < Kc
Kp > Kc
Pressure is required to predict the correlation
The solubility of CaF2 in pure water is 2.3 × 10-4 mol dm3. Its solubility product will be:
4.6 × 10-4
4.6 × 10-8
6.9 × 10-12
4.9 × 10-11