What is the change in internal energy (in J) of a system that absorbs 0.677 kJ of heat from its surroundings and has 0.438 kcal of work done on it?
To calculate the change in internal energy (ΔU) of a system, we need to take into account the heat absorbed (q) and the work done (w) on or by the system. The first step is to convert the given quantities to a common unit.
Given:
Heat absorbed (q) = 0.677 kJ
Work done (w) = 0.438 kcal
1 kJ = 1000 J
1 kcal = 4184 J
Converting the units:
Heat absorbed (q) = 0.677 kJ = 0.677 * 1000 J = 677 J
Work done (w) = 0.438 kcal = 0.438 * 4184 J = 1832.232 J
Now, we can calculate the change in internal energy (ΔU) using the equation:
ΔU = q + w
Substituting the given values:
ΔU = 677 J + 1832.232 J
ΔU = 2509.232 J
Therefore, the change in internal energy is 2509.232 J.