Question

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

Answer 1

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:  

$n = \dfrac{m}{MM}$

Solving:  

$n = \dfrac{m}{MM}$

$n = \dfrac{21.2\:\diagup\!\!\!\!\!g}{14\:\diagup\!\!\!\!\!g/mol}$

$\boxed{\boxed{n\approx 1.51\:mol}}\end{array}}\qquad\checkmark$

Answer:

1.51 mol

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

Answer 2

M(N)=21.2 g
M(N)=14.007 g/mol

n(N)=m(N)/M(N)

n(N)=21.2g/(14.007g/mol)=1.51 mol