Question

0.001 gram of carbon is required to write a letter with a graphite pencil the total number of carbon atoms used in writing the letter is

Answer 1

Answer:

3.76*10^19 atoms

Explanation:

moles used= given mass/molar mass

=0.001/16 moles

=0.0000625 moles

1 mole substance contains 6.022*10^23 atoms

=> 0.0000625 moles have

0.0000625*6.022*10^23 atoms

=3.76*10^19 atoms

Answer 2

Answer: $48.18\times 10^{19}$  atoms

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

given mass of Carbon = 0.001 g

Molar mass of Carbon= 12 g/mol

Putting in the values we get:

$\text{Number of moles}=\frac{0.001g}{12g/mol}=8\times 10^{-5}moles$

1 mole of $C$ contains= $6.022\times 10^{23}$  atoms  

Thus $8\times 10^{-5}moles$  moles of carbon $C$ contains=$\frac{6.022\times 10^{23}}{1}\times 8\times 10^{-5}=48.18\times 10^{19}$  atoms  

Thus the  total number of carbon atoms used in writing the letter is $48.18\times 10^{19}$  atoms .