I) distinguish a substance from a mixture. give 2 examples of each

Substance: matter with a specific composition and set of properties

Examples: Iron(Fe) and Gold (Au) all elements are considered a (pure) substance because they have the same uniform composition and properties throughout

Mixture: a combination of two or more substances which are physically combined

Examples: mixing oil and water, and dissolving salt in water

the product of the pressure and volume is also constant

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.