Answer:
-100 kJ
Explanation:
We can solve this problem by applying the first law of thermodynamics, which states that:

where:
is the change in internal energy of a system
Q is the heat absorbed/released by the system (it is positive if absorbed by the system, negative if released by the system)
W is the work done by the system (it is positive if done by the system, negative if done on the system)
For the system in this problem we have:
W = +147 kJ is the work done by the system
Q = +47 kJ is the heat absorbed by the system
So , its change in internal energy is:

Answer: The theoretical yield of aspirin is 4.14 g
Explanation:
To calculate the moles :
mass of acetic anhydride =
According to stoichiometry :
1 mole of salycylic acid require 1 mole of acetic anhydride
Thus 0.023 moles of salycylic acid require=
of acetic anhydride
Thus salycylic acid is the limiting reagent as it limits the formation of product and acetic anhydride is the excess reagent.
As 1 mole of salycylic give = 1 mole of aspirin
Thus 0.023 moles of salycylic acid give =
of aspirin
Mass of aspirin =
Thus theoretical yield of aspirin is 4.14 g
The answer is/6-(1-2)
Explain why it is not that because it shown
C = 4 mol/l
v = 0.5 l
n(NaCl)=cv
n(NaCl) = 4 mol/l · 0.5 l = 2 mol
2 moles of NaCl must be dissolved