Respuesta :

To calculate the number of moles of a substance, divide the amount of substance with the molar mass. The molar mass of nitrogen is approximately 14 grams per mole. Divide the given 21.2 g of N with the molar mass. The division will give an answer of 1.514 moles. Thus, there are approximately 1.514 moles of nitrogen in the sample. 
dexteright02

Hello!

If a sample contains 21.2 g N, how many moles of N does it contain?

0.66 mol

1.51 mol

14.01 mol

297.01 mol

We have the following data:  

m (mass) = 21.2 g

MM (Molar mass of Nitrogen) = 14 g / mol

n (number of moles) = ?

Formula:  

[tex]n = \dfrac{m}{MM}[/tex]

Solving:  

[tex]n = \dfrac{m}{MM}[/tex]

[tex]n = \dfrac{21.2\:\diagup\!\!\!\!\!g}{14\:\diagup\!\!\!\!\!g/mol}[/tex]

[tex]\boxed{\boxed{n\approx 1.51\:mol}}\end{array}}\qquad\checkmark[/tex]

Answer:

1.51 mol

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I Hope this helps, greetings ... Dexteright02! =)

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