A reaction produces 156 mL of carbon dioxide gas collected over water at a temperature of 25.0 °C and a pressure of 99.81
kPa. Calculate the volume of CO2 at STP.

150mL

Explanation:

at stp, pressure = 1atmospheres, temperature 20°C

V=156mL

T=25°C

P=99.81kPa =99.81*0.00986923=0.9850atm

P

1

V

1

T

1

=

P

2

V

2

T

2

V

2

=

V

1

×

P

1

P

2

×

T

2

T

1

=

156 mL

×

1.053

bar

1

bar

×

273.15

K

298.15

K

=

150 mL

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2

c. 4.54 x 10–12 j happens to be correct