Can anyone solve this 10TH GRADE CHEMISTRY question that has to do with PARTIAL PRESSURE

1) 2.5 g each of CH4, N2, and NH3 are contained in a 1.50 L flask at a temperature of 15ºC.
a. What is the partial pressure of NH3?
b. What is the total pressure?
c. What is the mole fraction of CH4?

2) Consider a mixture of 2 gases, A and B, confined to a closed vessel. A quantity of a third gas, C, is added to the vessel, at the same temperature.
a. does adding C affect the partial pressure of A?
b. does it affect the total pressure?
c. does it affect the mole fraction of B?

Thank you thank you thank you to all who answer :)

1) Ok, first you need to convert all of those gram values to moles. (Divide by molar mass.)
2.5 g CH4 = 0.156 mol CH4
2.5 g N2 = 0.089 mol N2
2.5 g NH3 = 0.147 mol NH3
Use these numbers to find the mole fraction.
0.156 / (0.156+0.089+0.147) = 39.8% (This is the answer to part c)
Use the ideal gas equation (PV=nRT) to find the total pressure (part b).
P(1.50)=(0.156+0.089+0.147)(0.0821)(15…
P=6.18 atm (This is the answer to b)
Use the mole fraction of NH3 to find the partial pressure.
Mole fraction = 37.5% (see work for part c)
Total pressure * mole fraction = partial pressure
6.18 atm * .375 = 2.32 atm (This is the answer to part a)
2) a. no, still same amount of A so pressure is the same
b. yes, more moles present so total pressure increased
c. yes, different total number of moles so mole fraction of B is different