The half-life of Th232 is 1.4 × 1010 years and that of its daughter element Ra238 is 7 years. What amount (most nearly) weight of Ra238 will be in equilibrium with 1 gm of Th232?
5.0 gm
1.95 × 10-9 gm
2 × 10-10 gm
5 × 10-10 gm
D.
5 × 10-10 gm
Since,
where, W = mass of substance taken; M = molar mass; N = actual number of particles; N0 = Avogadro number
Also, M (Th-232); M (Ra-238)
Which of the following are the correct representations of a zero order reaction, where A represents the reactant?
I, II, III
I, II, IV
II, III, IV
1, III, II
Which of the following statement(s) is/are true
The pressure of a fixed amount of an ideal gas is proportional to its temperature only
Frequency of collision increases in proportion to the square root of temperature
The value of van der Waal's constant'a' is smaller for ammonia than for nitrogen
If a gas is expanded at constant temperature, the kinetic energy of the molecules decrease
For the reaction 2A + B → C, the values of initial rate at different reactant concentrations are given in the table below. The rate law for the reaction is :
[A] (mol L-1) | [B] (mol L-1) | Initial rate (mol L-1 s-1) |
0.05 | 0.05 | 0.045 |
0.10 | 0.05 | 0.090 |
0.20 | 0.10 | 0.72 |
Rate = k[A]2[B]2
Rate = k[A]2[B]
Rate = k[A][B]
Rate = k[A][B]2
For a reaction scheme A , if the rate of formation of B is set to be zero then the concentration of B is given by:
(k1 + k2)[A]
(k1 - k2)[A]
k1k2[A]
The given plots represent the variation of the concentration of a reactant R with time for two different reactions (i) and (ii). The respective orders of the reactions are
0, 1
0, 2
1, 0
1, 1
A bacterial infection in an initial wound grows N0(t) = N0 exp(t), here the time t is in hours A dose of antibiotic, taken orally , needs 1 hour to reach the wound. Once it reaches there , the bacterial Population goes down as . what will be plot of
For the reaction of H2 with I2, the rate constant is 2.5 × 10-4 dm3 mol-1s-1 at 327°C and 1.0 dm3 mol-1s-1 at 527°C. The activation energy for the reaction, in kJ mol-1 is: (R= 8.314 Jk-1mol-1)
166
150
59
72