Sometimes people say that the air is thinner high up on a mountain is that true

Yes

Explanation:

As altitude increases, the amount of gas molecules in the air decreases—the air becomes less dense than air nearer to sea level. This is what is meant by "thin air".

Yes because the air becomes less compressed and is therefore thinner.

Explanation:

the temperature of the gas, in k, not celsius.

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.