What is the number of moles in 500l of he gas at stp

What pressure will be exerted by 0.675 moles of a gas at 25*c if it is in a 0.750-l container?

Seltzer water is created by placing water under pressure with carbon dioxide gas. which of the following statements best describe seltzer water: a. the solution will be slightly acidic b. the solution will be slightly basic. the solution will be strongly acidic. d. the solution will be strongly basic. e. the solution will be neutral

Avariable that is not being directly tested during an experiment should be changed varied experimented controlled