Calculate the enthalpy for the following reaction. During the reaction, the temperature changes from 42.5 C to 37 C. The specific heat of HCl is 4.04J/g*C. Is the reaction endothermic or exothermic?

Kj/mol

Its an endothermic reaction

Explanation:

Enthalpy can be evaluated by using following formula -

where

q is the enthalpy or change in internal energy

m is the mass in kg

c is the specific heat

and is the change in temperature

Mass of HCl is equal to g/mol

or

Mass of HCl is equal to  Kg/mol

Substituting the given values in above equation, we get-

Kj/mol

Enthalpy is positive thus it is an endothermic reaction

first one is the correct answer