Answer: 20.7 kJ
Explanation:
According to first law of thermodynamics:
=Change in internal energy
q = heat absorbed or released
w = work done or by the system
w = work done on the system=
{Work is done on the system is positive as the final volume is lesser than initial volume}
w = 4.51 kcal =
(1kcal = 4.184kJ)
q = +1.79 kJ {Heat absorbed by the system is positive}

Thus
for a system that receives 1.79 kJ of heat from surroundings and has 4.51 kcal of work done on it at the same time is 20.7 kJ
Answer:
<em>Answer Below</em>
Explanation:
Percent composition by element
<u>Element </u> <u>Symbol</u> <u>Mass Percent</u>
Aluminium <u>Al</u> 34.590%
Hydrogen <u>H</u> 3.877%
Oxygen <u>O</u> 61.533%