Answer:
It is 0.05 moles of water
Explanation:
From avogadro's number:
[tex]{ \sf{6.02 \times {10}^{23} \: mole cules= 1 \: mole }} \\ { \sf{3 \times {10}^{22} \: molecules = ( \frac{3 \times {10}^{22} }{6.02 \times {10}^{23} }) \: moles }} \\ \\ { \sf{ = 0.05 \: moles}}[/tex]
Answer:
[tex]\boxed {\boxed {\sf 0.05 \ mol \ H_2O}}[/tex]
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.
[tex]\frac {6.022 \times 10^{23} \ molecules \ H_2O} { 1 \ mol \ H_2O}[/tex]
We are converting 3 × 10²² molecules of water to moles, so we must multiply the ratio by this value.
[tex]3 \times 10^{22} \ molecules \ H_2O*\frac {6.022 \times 10^{23} \ molecules \ H_2O} { 1 \ mol \ H_2O}[/tex]
Flip the ratio so the units of molecules of water cancel.
[tex]3 \times 10^{22} \ molecules \ H_2O*\frac{ 1 \ mol \ H_2O} {6.022 \times 10^{23} \ molecules \ H_2O}[/tex]
[tex]3 \times 10^{22} *\frac{ 1 \ mol \ H_2O} {6.022 \times 10^{23}}[/tex]
[tex]\frac {3 \times 10^{22}} {6.022 \times 10^{23}} \ mol \ H_2O[/tex]
[tex]0.04981733643 \ mol \ H_2O[/tex]
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.
[tex]0.05 \ mol \ H_2O[/tex]
3×10²² molecules of water are equal to 0.05 moles of water.
