A cylinder with a movable piston contains 7.00 moles of helium. What is the final amount of moles in the cylinder if the volume was changed from 8.00 L to 12.7 L? this is on boyles , charles law , avogadros , and combined unit.

any helps is appreciated:))

How many liters of hydrogen gas will be produced at stp from the reaction of 7.179×10^23 atoms of magnesium with 54.219g of phosphoric acid (h3po4) the equation is 3mg + 2h3(> mg(po4)2+3h2

Using a value of ksp = 1.8 x 10-2 for the reaction pbcl2 pb+2(aq) + 2cl -(aq). if the value of ksp was determined to be only 1.2 x 10-2: too much solid has dissolved. additional precipitate is forming. the solution is unsaturated. the ions are now combining to reduce their concentrations.

How many moles of gas are present if p=11 atm, v=12l, t=185k?