Question

Calculate the moles in 3x10^22molecules of water

Answer 1

It is 0.05 moles of water

Step-by-step explanation:

From avogadro's number:

`{ \sf{6.02 * {10}^(23) \: mole cules= 1 \: mole }} \\ { \sf{3 * {10}^(22) \: molecules = ( \frac{3 * {10}^(22) }{6.02 * {10}^(23) }) \: moles }} \\ \\ { \sf{ = 0.05 \: moles}}`

Answer 2

`\boxed {\boxed {\sf 0.05 \ mol \ H_2O}}`

Step-by-step explanation:

We are asked to calculate the number of moles of water, given the molecules of water.

We will convert moles to molecules using Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. In this case, the particles are molecules of water or H₂O.

We will convert using dimensional analysis, so we must set up a ratio using Avogadro's Number.

`\frac {6.022 * 10^(23) \ molecules \ H_2O} { 1 \ mol \ H_2O}`

We are converting 3 × 10²² molecules of water to moles, so we must multiply the ratio by this value.

`3 * 10^(22) \ molecules \ H_2O*\frac {6.022 * 10^(23) \ molecules \ H_2O} { 1 \ mol \ H_2O}`

Flip the ratio so the units of molecules of water cancel.

`3 * 10^(22) \ molecules \ H_2O*\frac{ 1 \ mol \ H_2O} {6.022 * 10^(23) \ molecules \ H_2O}`

`3 * 10^(22) *\frac{ 1 \ mol \ H_2O} {6.022 * 10^(23)}`

`\frac {3 * 10^(22)} {6.022 * 10^(23)} \ mol \ H_2O`

`0.04981733643 \ mol \ H_2O`

The original value of molecules of water ( 3 × 10²² ) has 1 significant figure, so our answer must have the same number of sig figs. For our answer that is the hundredth place. The 9 in the thousandth place tells us to round the 4 in the hundredth place up to a 5.

`0.05 \ mol \ H_2O`

3×10²² molecules of water are equal to 0.05 moles of water.