Step-by-step explanation:
Partial pressure of a gas is the product of the mole fraction of that gas, which is the ratio of the no. of moles of the gas to the total no. of moles, and the total pressure.
total no. of moles=0.74+0.25=0.99 mol
mole fraction of N2=0.74/0.99=0.7475
mole fraction of O2=0.25/0.99=0.2525
total pressure=1.7+4.7=6.4 atm
partial pressure of N2=0.7475×6.4=4.784 atm
partial pressure of O2=0.2525×6.4=1.616 atm