1. which of the following statements is not true about double-replacement reactions? a. the product may precipitate from solution. b. the product may be a gas. c. the product may be a molecular compound. d. the reactant may be a solid metal. 2. the complete combustion of which of the following substances produces carbon dioxide and water? a. c8h18 b. k2co3 c. cahco3 d. no 3. the equation mg(s) + 2hcl(aq) + h2(g) is an example of which type of reaction? a. combination reaction b. single-replacement reaction c. decomposition reaction d. double-replacement reaction

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.