Which of the changes are chemical changes? a. Candle wax is melted. b. A candle is burned. c. A silver teapot turns black. d. Two clear colorless salt solutions are mixed and a bright orange precipitate forms. e. Sugar crystals are ground to a fine powder.

• A candle is burned

• Your silver teapot turns black

• Two clear colorless salt solutions are mixed and a bright orange precipitate forms.

Explanation:

A chemical change results from a chemical reaction of the species involved. Examples of chemical changes are burning, cooking, rusting etc.

Physical change when matter changes forms but not chemical identity. Examples of physical changes are boiling, melting, freezing, evaporation etc.

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.