Question

How many moles are in 4.1 x10 22 molecules of NaCl?

Answer 1

It would be 12.46 I hope this helps

Answer 2

`\boxed {\boxed {\sf 0.068 \ mol \ NaCl}}`

Step-by-step explanation:

To convert from molecules to moles, Avogadro's Number must be used. This number is 6.022 *10²³. It tells us the number of particles (atoms, molecules, etc.) in 1 mole of a substance.

In this case, the particles are molecules of sodium chloride. We can make a ratio.

`\frac {6.022*10^(23) \ molecules \ NaCl}{ 1 \ mol \ NaCl}`

Multiply by the given number of molecules.

`4.1*10^(22) \ molecules \ NaCl *\frac {6.022*10^(23) \ molecules \ NaCl}{ 1 \ mol \ NaCl}`

Flip the fraction so the moles of sodium chloride cancel.

`4.1*10^(22) \ molecules \ NaCl *\frac {1 \ mol \ NaCl}{6.022*10^(23) \ molecules \ NaCl }`

`4.1*10^(22) *\frac {1 \ mol \ NaCl}{6.022*10^(23) }`

`\frac {4.1*10^(22) \ mol \ NaCl}{6.022*10^(23) }`

`0.06808369313 \ mol \ NaCl`

The original measurement of molecules has 2 significant figures, so our answer must have the same. For the number we calculated that is the thousandth place.

The 0 in the ten thousandth place tells us to leave the 8.

`0.068 \ mol \ NaCl`

There are 0.068 moles of sodium chloride.