Answer:
The steps are outlined in the explanation below.
Explanation:
The average velocity is derived midpoint from the initial to the final velocity. Here is the proof:
Find the total displacement:
let the displacement be given by the letter s
Then since the average velocity is defined as:
where t = final time
t₀ = initial time
v = final speed
v₀ = initial time
where x denotes the position, then
where v = and dx = change in distance with respect to time.
Answer : The correct option is, (B) -5448 kJ/mol
Explanation :
First we have to calculate the heat required by water.
where,
q = heat required by water = ?
m = mass of water = 250 g
c = specific heat capacity of water =
= initial temperature of water = 293.0 K
= final temperature of water = 371.2 K
Now put all the given values in the above formula, we get:
Now we have to calculate the enthalpy of combustion of octane.
where,
= enthalpy of combustion of octane = ?
q = heat released = -81719 J
n = moles of octane = 0.015 moles
Now put all the given values in the above formula, we get:
Therefore, the enthalpy of combustion of octane is -5448 kJ/mol.