The decay constant of a radioactive sample is λ. The half-life and mean life of the sample are, respectively
B.
All radioactive changes follow first order kinetics and for first order reaction,
When t = t1/2; x =
or half life, t1/2 =
Mean life =
Which of the following is a first order reaction?
NH4NO2 →N2 + 2H2O
2HI → H2 + I2
2NO2 → 2NO + O2
2NO + O2 → 2NO2
In the reaction of A + 2B → C + 2D, the initial rate = att = 0 wasfound to be 2.6 × 10-2 M s-1. What is the value of at t = 0 in Ms-1 ?
2.6 × 10-2
5.2 × 10-2
1.0 × 10-1
6.5 × 10-3
Copper sulphate solution is electrolysed using copper electrode. The reaction taking place at anode is
H+ + e- → H
SO (aq) → SO4 + 2e-
Cu2+ + 2e- → Cu
Cu (s) → Cu2+ (aq) + 2e-
How many cc of oxygen will be liberated by 2 A current flowing for 3 min 13 s through acidulated water?
11.2 cc
33.6 cc
44.8 cc
22.4 cc
Which of the following will have the highest coagulating power for As2S3 colloid?
PO
SO
Al3+
Na+
Adsorption is multilayer in the case of
physical adsorption
chemisorption
Both (a) and (b)
None of the above
In electrorefining of metal, the impure metal is made the anode and a strip of pure metal the cathode during the electrolysis of an aqueous solution of a complex metal salt. This method cannot be used for refining of
silver
copper
aluminium
zinc