Ok

So we have to use the formula PV = nRT

P is in atm and we must subtract the vapor pressure from the total pressure always because the pressure of the nitrogen gas does not include the pressure produced by vapor pressure

And so we convert the 17.5 torr to atm by dividing by 760... and we get .023 atm as water vapor pressure

So 1.18 - .023 is 1.157 atm = P

Now, V is 2.6 times 102 mL as you said so thats 265.2 mL... we have to convert that to liters by dividing by 1000 and we get .2652 L

R is the ideal gas constant 8.3145 J/mol K

T is 20 degrees C + 273.15 K to get 293.15 K

Now lets plug and chug

.023 atm (.2652 L) = n (8.3145 J/mol K)( 293.15 K)

n is in moles

n = 2.5025 * 10^-6

Now just convert that moles to grams of N and you have your answer!