How many molecules are there in 14g of nitrogen gas at s.t.p? (n = 14, Avogadro Number = 6. 0 x \(10^{23 }\)mol-1)
1.2 x 10 23
3.0 x 1023
6.0 x1023
1.2 x 1024
30 x1023
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Molar mass of nitrogen molecule N2 is 28g.
Number of moles of nitrogen is given by:
No. of moles = Given mass/ molar mass
So, no. of moles = 14/28 = 0.5 moles
Now in 1 mole number of atoms is given by the
Avogadro number i.e 6.023exp(23).
No. of atoms in 14g of nitrogen
= 0.5*6.023exp(23)
=3.011exp(23) atoms
The selected answer is wrong.
Nitrogen is diatomic.
So, if 28g of Nitrogen contains 6.02×10²³ molecules
:• 14g of Nitrogen contains (14×6.02×10²³)/28
= 3.01×10²³ (B)
Myschool, please correct it!
To solve this problem, we can use the ideal gas law which relates the number of molecules, moles, pressure, volume, and temperature of a gas.
At STP (Standard Temperature and Pressure), the pressure is 1 atm and the temperature is 273 K. The molar volume of a gas at STP is 22.4 L/mol.
We can start by calculating the number of moles of nitrogen gas in 14g using its molar mass:
Molar mass of nitrogen gas = 28 g/mol
Number of moles of nitrogen gas = 14 g / 28 g/mol = 0.5 mol
Then, we can use Avogadro's number to convert from moles to number of molecules:
Number of molecules of nitrogen gas = 0.5 mol x 6.0 x 10^23 molecules/mol = 3.0 x 10^23 molecules
Therefore, the answer is B. 3.0 x 10^23 molecules.
In this question the molar mass to be used is 28 since nitrogen is a diatomic molecule. With that in mind the formulae to be used would be mass/molarmass = number of entities/Avogrado's number. If solved correctly the right answer will be B
