Please help me thanks so much??!!.:;))..I will mark you:))

If a gas has an initial pressure of 101kpa and a volume of 10l, then it expands to a volume of 20l, what is the new pressure?

When a chemist collects hydrogen gas over water, she ends up with a mixture of hydrogen and water vapor in her collecting bottle. if the pressure in the collecting bottle is 97.1 kilopascals and the vapor pressure of the water is 3.2 kilopascals, what is the partial pressure of the hydrogen?

Ireally need ! calcium metal reacts with a potassium chloride solution to form calcium chloride and potassium ions. balance this reaction. (s) + (aq) → cacl2(s) + +(aq) a) 1, 2, 1, 2 b) 1, 2, 1, 1 c) 1, 1, 1, 1 d) 2, 1, 2, 1