Carbon occurs in nature as a mixture of C-12 and C-13. The average atomic mass of carbon is 12.011 What is the percentage abundance of C-12 in nature.

Question

Carbon occurs in nature as a mixture of C-12 and C-13. The average atomic mass of carbon is 12.011 What is the percentage abundance of C-12 in nature. (A) 4% (B) 98.9% (C) 48% (D) 1.1%

Tardigrade Admin · Accepted Answer

Let x be the percentage abundance of C-12; then (100 - x) will be the percentage abundance of C-13. ∴ (12x/100) + (13(100 - x)/100) = 12.011 12x + 1300 - 13x = 1201 .1 ⇒ x = 98.9 ∴ Abundance of C-12 = 98.9 %

Q. Carbon occurs in nature as a mixture of $C - 12$ and $C - 13$ . The average atomic mass of carbon is $12.011$ What is the percentage abundance of $C - 12$ in nature.

4%

98.9%

48%

1.1%

Let $x$ be the percentage abundance of $C - 12$ ; then
$(100 - x)$ will be the percentage abundance of $C - 13$ .
$∴ \frac{12 x}{100} + \frac{13 ( 100 - x )}{100} = 12.011$
$12 x + 1300 - 13 x = 1201.1$
$\Rightarrow x = 98.9$
$∴$ Abundance of $C - 12 = 98.9%$

Q. Carbon occurs in nature as a mixture of C−12 and C−13. The average atomic mass of carbon is 12.011 What is the percentage abundance of C−12 in nature.

4%

98.9%

48%

1.1%

Let x be the percentage abundance of C−12; then (100−x) will be the percentage abundance of C−13. ∴10012x​+10013(100−x)​=12.011 12x+1300−13x=1201.1 ⇒x=98.9 ∴ Abundance of C−12=98.9%

Q. Carbon occurs in nature as a mixture of $C - 12$ and $C - 13$ . The average atomic mass of carbon is $12.011$ What is the percentage abundance of $C - 12$ in nature.

Let $x$ be the percentage abundance of $C - 12$ ; then
$(100 - x)$ will be the percentage abundance of $C - 13$ .
$∴ \frac{12 x}{100} + \frac{13 ( 100 - x )}{100} = 12.011$
$12 x + 1300 - 13 x = 1201.1$
$\Rightarrow x = 98.9$
$∴$ Abundance of $C - 12 = 98.9%$