Boyle's law states that pressure is inversely proportional to volume of gas at constant temperature
PV = k
where P - pressure , V - volume and k - constant
P1V1 = P2V2
where parameters for the first instance are on the left side and parameters for the second instance are on the right side of the equation
substituting these values in the equation
1.25 atm x 0.75 L = P x 1.1 L
P = 0.85 atm
final pressure is B) 0.85 atm
Protium - the most common isotope of hydrogen - has no neutrons in its nucleus.
moles = molarity * 1000/volume
7*1000/14.44= 484.76