The solubility product of PbI₂ is 7.47×10⁻⁹ at 15^oC and 1.39×10⁻⁸ at 25^oC. Calculate the molar heat of solution of PbI₂.

1) 443KJ/mol
2) 0.443KJ/mol
3) 4.43KJ/mol
4) 44.3KJ/mol

There are 10 different objects 1,  2,  3,  ... 10 arranged at random in 10 places marked 1,  2,  3,  ... , 10. The probability that exactly five of these objects occupy places corresponding to their number is

1) 13/ 3600
2) 11/ 3600
3) 17/ 3600
4) none

An object of mass m is hanging by a string from the ceiling of an elevator. The elevator is moving upward, but slowing down. What is the tension in the string?

1) Less than mg. 2) Exactly mg. 3) Greater than mg. 4) Zero.   

For the function  which of the following is incorrect?

1) Continuous at x=1
2) Continuous at x=3
3) Derivable  at  x =1
4) Derivable  at  x =3

A ceiling fan rotates about its own axis with some angular velocity. When the fan is switched off, the angular velocity becomes (1/4)th of the original in time ′t′ and ′n′ revolutions are made in that time. The number of revolutions made by the fan during the time interval between switch off and rest are (Angular retardation is uniform).
1) 4n /15
2) 8n/15
3) 16n /15
4) 32n / 15 

A biased coin with probability $$p$$, (0$$< p < $$1) of showing head is tossed until a head appears for the first time. If the probability that the number of tosses required is odd is $$\displaystyle \frac{7}{11}$$  then $$p$$ =

The name written on the card is the name of a boy.

1) $$\displaystyle \frac{4}{7}$$
2) $$\displaystyle \frac{3}{7}$$
3) $$\displaystyle \frac{4}{11}$$
4) $$\displaystyle \frac{2}{3}$$

A catalyst in the finely divided state is more efficient because in this state

1)  it can react with one of the reactant more efficiently

2)  it has larger activation energy

3)  it has large surface area

4)  all of the above

$$A$$ and $$B$$ are two events where $$P(A) = 0.25$$ and $$P(B) = 0.5$$. The probability of both happening together is $$0.14$$. The probability of both $$A$$ and $$B$$ not happening is

1) $$\displaystyle 0.39$$
2) $$\displaystyle 0.25$$
3) $$\displaystyle 0.11$$
4) none of these

The gas evolved on heating CH₃MgBr in methanol is:

1) ethane
2) HBr
3) propane
4) methane

A piece of ice (heat capacity = 2100 J kg ^-1 °C^-1 and latent heat = 3.36 × 10⁵J kg ^-1) of mass m gram is at –5°C at atmospheric pressure. It is given 420 J of heat, so that the ice starts melting. Finally when the ice-water mixture is in equilibrium, it is found that 1 g of ice has melted. Assuming there is no other heat exchange in the process, the value of m is

1) 8
2) 6
3) 4
4) 8.5