please rate me if my solution is correct

LET us say that volume of mercury poured in vessel bev.

so vol of the air initially is 1000 - v        -----------------equ.1

let the temperature is raised by dt  so final volume of vessel will be 1000(1+1*dt) ------------------------equ.2

and final volume of mercury is v(1+2*dt)----------------------eqa 3

where         are coeff of vol exp. of vessel and mercury respectively

now as given in question the vol of air doed not changed so eqa 1=eqa2  --  eqa 3

solving which we finally get  

which gives v=50 cc

Please solve questions of HC VERMA Part-2 of the chapters mentioned

ch1.HEAT AND TEMPERATURE----Q.11,21,23,24,30,31

ch.2.KINETIC THEORY OF GASES----Q. 13,22(b),34,36,37,40

ch3.LAWS OF THERMODYNAMICS ---Q10,18

ch.4 SPECIFIC HEAT CAPACITIES-----Q4,6

ch.5 HEAT TRANSFER-------Q29,33,36,37,52

HC VERMA PART -2 ,please solve

Heat and temperature-Q .11 ,23,24,30,31    (page no. 13,14)

Kinetic theory of gases-Q. 13,22(part b),32,34,36,37,40

Q.An eight digit number divisible by 9 is to be formed by using 8 digits out of digits 0,1,2,3,4,5,6,7,8,9 without replacement .The no of ways in which this can be done is:

{ans-(36)*7!

Q.An five digit number divisible by 6 is to be formed by using the digits 0,1,2,3,4,8 without repetition. The no of ways in which this can be done is:

{ans-150}

is answer d/v

Q How SO2 contains 2 sigma and 2 pi bonds.