When fuel is burned in a cylinder equipped with a piston, the volume expands from 0.255 l to 1.45 l against an external pressure of 1.02 atm. in addition, 875 j is emitted as heat. what is the de for the burning of the fuel?

Answer : The value of for the burning of the fuel is, -998.5 joules.

Explanation :

First we have to calculate the work done.

Formula used :

where,

w = work done  = ?

= external pressure = 1.02 atm

= initial volume of gas = 0.255 L

= final volume of gas = 1.45 L

Now put all the given values in the above formula, we get :

conversion used : (1 L.atm = 101.3 J)

Now we have to calculate the change in internal energy of the system.

Therefore, the value of for the burning of the fuel is, -998.5 joules.

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