Answer to Question #168125 in General Chemistry for Jason Israel

Question

How many moles are in 4.1x10 to the 22nd power molecules of NaCl

Answer 1

Q168125

How many moles are in 4.1x10 to the 22nd power molecules of NaCl?

Solution:

We are given the number of molecules of NaCl and have to convert it to 'moles of NaCl'.

One mole of a substance contains Avagadro's number of molecules or atoms.

1 mol = 6.022 * 10²³ molecules.

Using this as a conversion factor, we can find the '# of moles of NaCl' in 4.1 * 10²² molecules of NaCl.

$No.\space of\space moles\space of\space NaCl = 4.1 * 10^{22} \space molecules\space of\space NaCl * \frac{1\space mol\space NaCl }{6.022 * 10^{23}\space molecules\space of\space NaCl }$

$= 0.0681\space mol\space of\space NaCl$

In the question, we are given 4.1 * 10²² molecules in 2 significant figures, so our final answer must also be in 2 significant figures.

Hence there are 0.068 moles of NaCl in 4.1 * 10²² molecules of NaCl.

Sometimes you may have to submit your answer in scientific notation.

Move the decimal point two times to the right to get 6.8 * 10^-2 moles of NaCl as the answer.

The power of 10 is decreased by 2 because we have moved the decimal point two times to the right side.

Also, refer to the image I have uploaded.

Thank you. :)