21 which mathematical expression represents the heat of reaction for a chemical reaction? (1) (the heat of fusion) – (the heat of vaporization)
(2) (the heat of vaporization) – (the heat of fusion)
(3) (the potential energy of the products) – (the potential energy of the reactants)
(4) (the potential energy of the reactants) – (the potential energy of the products)

C=59(f−32)the equation above shows how temperature f, measured in degrees fahrenheit, relates to a temperature c, measured in degrees celsius. based on the equation, which of the following must be true? a temperature increase of 1 degree fahrenheit is equivalent to a temperature increase of 59 degree celsius.a temperature increase of 1 degree celsius is equivalent to a temperature increase of 1.8 degrees fahrenheit.a temperature increase of 59 degree fahrenheit is equivalent to a temperature increase of 1 degree celsius.a) i onlyb) ii onlyc) iii onlyd) i and ii only