2
C
4
H
10
(
g
) + 13
O
2
(
g
) = 8
C
O
2
(
g
) + 10
H
2
O
(
g
)
Answer:
ΔE = 150 J
Explanation:
From first law of thermodynamics, we know that;
ΔE = q + w
Where;
ΔE is change in internal energy
q is total amount of heat energy going in or coming out
w is total amount of work expended or received
From the question, the system receives 575 J of heat. Thus, q = +575 J
Also, we are told that the system delivered 425 J of work. Thus, w = -425 J since work was expended.
Thus;
ΔE = 575 + (-425)
ΔE = 575 - 425
ΔE = 150 J
Answer:
Increasing the surface area of the reactants
Explanation:
An increase in surface area of the reactant will always cause an increase in the rate of reaction. This is so because, an increase in the surface area of the reactant will cause the reactant particles to collide effectively thereby bringing about an increase in the reaction rate.
Collision theory suggests that for a reaction to occur, the reactant particles must collide with the right orientation. As the surface area of the reactants are increased, the reactants particles collide more with the right orientation bringing about definite increase in the rate of reaction.
Answer : The standard enthalpy of formation of ethylene is, 52.4 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The formation reaction of 
will be,
The intermediate balanced chemical reaction will be,
(1) 
(2) 
(3) 
Now we will reverse the reaction 1, multiply reaction 2 and 3 by 2 then adding all the equation, we get :
(1) 
(2) 
(3) 
The expression for enthalpy of formation of will be,
Therefore, the standard enthalpy of formation of ethylene is, 52.4 kJ
Answer:
The total pressure would be 8, 93 atm
Explanation:
We apply Dalton's laws, where for a gaseous mixture, the total pressure (Pt) is the sum of the partial pressures (Px) of the gases that make up the mixture.
Pt= Pxa + Pxb+ Pxc....
Pt=2, 20 atm+ 6, 70 atm+ 0,03 atm= 8, 93 atm
