Respuesta :
Answer: There are [tex]16.14 \times 10^{23}[/tex] atoms of hydrogen are present in 40g of urea, [tex](NH_{2})_{2}CO[/tex].
Explanation:
Given: Mass of urea = 40 g
Number of moles is the mass of substance divided by its molar mass.
First, moles of urea (molar mass = 60 g/mol) are calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{40 g}{60 g/mol}\\= 0.67 mol[/tex]
According to the mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] atoms.
So, the number of atoms present in 0.67 moles are as follows.
[tex]0.67 mol \times 6.022 \times 10^{23} atoms/mol\\= 4.035 \times 10^{23} atoms[/tex]
In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.
[tex]4 \times 4.035 \times 10^{23} atoms\\= 16.14 \times 10^{23} atoms[/tex]
Thus, we can conclude that there are [tex]16.14 \times 10^{23}[/tex] atoms of hydrogen are present in 40g of urea, [tex](NH_{2})_{2}CO[/tex].
