What is δe in kj 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. 1 cal = 4.184 j.

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

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.