Question

Calculate the mass of 120cc of nitrogen gas at ntp.How many number of molecules are present in it.Easy step of mole concept​

Answer 1

To calculate the mass of 120cc of nitrogen gas at NTP and the number of molecules present in it, you can use the gas density equation and Avogadro's number.

Step-by-step explanation:

To calculate the mass of 120cc of nitrogen gas at NTP (normal temperature and pressure), we need to use the gas density equation. The molar mass of nitrogen (N₂) is 28.01 g/mol. Substituting this value along with standard temperature (273K) and pressure (1.00 atm) into the gas density equation, we can find the mass of the nitrogen gas.

The number of molecules present can be calculated using Avogadro's number, which is 6.02×10^23 molecules/mol. Divide the mass of the nitrogen gas by the molar mass to get the number of moles, and then multiply by Avogadro's number to get the number of molecules.

Therefore, the mass of 120cc of nitrogen gas at NTP is (mass calculation) and the number of molecules present is (number of molecules calculation).

Answer 2

Step-by-step explanation:

The formula of nitrogen gas is given as;

N₂

Given volume of the gas = 120cm³

Now,

We need to find the number of molecules and the mass of this compound

Solution:

At STP;

1 mole of gas occupies a volume of 1dm³ ;

1000cm³ = 1dm³

120cm³ gives 0.12dm³;

Now;

1dm ³ of gas contains 1 mole of substance at STP

0.12dm³ will contain 0.12mole of nitrogen gas at STP

Mass of N₂ gas = number of moles x molar mass of N₂

Molar mass of N₂ = 2(14) = 28g/mol

Mass of N₂ = 0.12 x 28 = 3.36g

1 mole of a substance contains 6.02 x 10²³ molecules

0.12 mole of N₂ will contain 0.12 x 6.02 x 10²³ = 7.22 x 10²²molecules