7.50 mL of 2.00 M sodium hydroxide was added to 13.8 mL of 1.20 M hydrochloric acid in a coffee-cup calorimeter. The
maximum temperature change was determined to be +9.05°C.
Determine the enthalpy of neutralization for one mole of water produced in an acid-base neutralization reaction.

Idon't see the pic?

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).