Physical Chemistry Answers

What would be the volume of 76 g of fluorine gas ( molar mass equal to 38 g/mole) at a pressure of 0.821 atm and a temperature of 27 degree Celsius?

a) 30L

b) 60 L

c) 90 L

d) 600 L

What is the empirical formula of a compound that is by mass 50% element A ( whose molar mass is 38) and 50% element B ( whose molar mass is 19)?

a) A2B
b) AB2
c) AB
d) A2B2

The solubility product of PbI2 is 7.47x10^(-9) at 15*C & 1.39x10^(-8) at 25*C. Calculate the molar heat of solution of PbI2.

What is the density of helium gas at 25 degree celsius and 760 torr?

R= 0.082 Lxatm/molxk
AW= 4 g/mole

a) 0.16 g/L

b) 6.1 g/L

c) 124 g/L

d) 0.082 g/L

The pOH of a solution is found to be 9. What is the hydrogen ion ( H1+) concentration for this solution?

a) 1x10^-5

b) 1x10^-9

c) 1x10^-3

d) 1x10^-12

If a solution is 0.001 M in NaOH, what is the pH?

a) 3

b) 4

c) 7

d) 11

A gas sample occupies a volume of 1000 mL at 40 degrees celsius and a pressure of 760 torr. If , at the same temperature, the pressure were decreased to 380 torr, what volume would result?

a) 500 mL

b) 1000 mL

c) 1500 mL

d) 2000 mL

What volume of 0.1 M NaOH is needed to titrate 100 mL of 0.2 M H2SO4?

a) 50 mL

b) 100 mL

c) 200 mL

d) 400 mL

In order to initiate combustion in solids, it is usually necessary to raise their temperature by means of an external heat source. Under certain conditions, however, some material may generate the necessary heat internally. Give two examples of materials that can exhibits this phenomenon. In each case state how internal heating arises and outline the precautions that should be taken when they are stored to prevent combustion from occurring