How many moles are in 75.0 grams of nitrogen gas, N2?

Given:                                                                                                                      

Mass of Nitrogen (N₂) gas = 75 grams

Finding the number of moles of N₂:                                                                    

We know that the molar mass of N₂ is 28 grams/mole

Number of moles = Given mass / Molar mass

Number of moles = 75 / 28

Number of moles = 2.68 moles

Hence, there are 2.68 moles in 75 grams of Nitrogen Gas

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when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml