Question

To eight significant figures, Avogadro's constant is 6.0221367×10^(23)mol−1. Which of the following choices demonstrates correct rounding?
Check all that apply.

a. 6.022×1023mol−1
b. 6.0×1023mol−1
c. 6.02214×1023mol−1

Answer 1

Answer with Explanation:

We are given Avogadro's constant =$6.0221367\times 10^{23}mol^{-1}$

There are eight significant figures.

We have to round off.

1.If we round off to four significant figures

The ten thousandth place of Avogadro's constant is less than five therefore, digits on left side of ten thousandth  place remains same and digits on right side of ten thousandth place and ten thousandth place  replace by zero.

 Then ,Avogadro's constant can be written as

$6.022\times 10^{23}mol^{-1}$

If we round off to 2 significant figures

Hundredth place of given number is less than 5 therefore, digits on left side of hundredth  place remains same and digits on right side of hundredth place and hundredth place replace by zero.

Then,Avogadro's constant can be written as

$6.0\times 10^{23}mol^{-1}$

If we round off six significant figures

6 is greater than 5 therefore, 1 will be added to 3 and digits on right side of 6 and 6 replace by zero and digits on left side of 6 remains same except 3.

Then, the Avogadro's constant can be written as

$6.02214\times 10^{23}mol^{-1}$