Calculate partial pressure in dry air of NO given total pressure and temp?

Question

Use the data in Table 5.4 to calculate the partial pressure of NO in dry air assuming that the total pressure is 1.0 atm. Assuming a temperature of 0°C, calculate the number of molecules of NO per cubic centimeter. Component: NO Mole Fraction: 0.0000005

Answer 1

Calculate partial pressure in dry air of NO given total pressure and temp?

I don't know what table 5.4 is,...as long as this 1 atm is dry air:

the partial pressure is the same as the mole fraction

mole fraction of 0.0000005 , .... or 5e-7 moles NO per mole mix,  has a partial pressure of

5e-7 atm  out of the 1 atm

your answer is 5e-7 atm NO

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if table 5.4 is a vapor pressure table, then we need to decrease the total pressure of 1 atm by the water vapor pressure at 0 celsius, which is 0.006 atm = 0.994 atm

then the partial pressure of NO is (5e-7)(0.994) = 4.97e-7

but why bother, considering significant digits ... it is still rounds off to 5e-7atm

but  i still wish I knew what table 5.4 was all about

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assuming that the total pressure is 1.0 atm. Assuming a temperature of 0°C, calculate the number of molecules of NO per cubic centimeter.

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calculate the moles in one cubic centimetre, (1e-3 litres):

PV=nRT

(5e-7atm)(1e-3litres) = n (0.08206L-atm/mol-K)(273K)

n= 2.23e-11 moles of NO are in that 1 cc (aka 1e-3Litres)

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calc the molecules in that 1cc:

2.23e-11 mol NO @ 6.022e23 molecules / mole = 1.34e13

your answer is 1.3 e13 molecules per cc