2.3 mols of Al*26.98 molar mass of Al=62.054g
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
That statement is true
it was easy to organize 'all' the elements in a group of threes because back then they only knew about 15 - 20 elements
hope this helps
the numbers are going to be small so like a power but its at the bottom
NH3, H2O2, NHO2