The heat of fusion for a substance is 122 joules per gram. how many joules of heat are need to melt 7.50 grams of this substance at its melting point?

915 Joules

1 g = 122 Joules

7.5 g = ?

       = 122 × 7.5

      = 915 Joules

Thus, 7.5 g of the substance at its melting point will require 915 Joules of heat to melt.

c, liquids evaporate, creating a gas

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.