Respuesta :
Answer:
[tex]\boxed {\boxed {\sf A. \ About \ 5.14 *10^{24} \ molecules \ H_2O}}[/tex]
Explanation:
To convert from moles to units, we must use Avogadro's Number: 6.022 * 10²³
This tells us the number of units (molecules of water in this problem) in 1 mole of a substance (water). We can use it as a ratio or fraction.
[tex]\frac{6.022 *10^{23} \ molecules \ H_2O}{1 \ mol \ H_2 O}[/tex]
Now, we can multiply this fraction by the moles of water (8.54) given.
[tex]8.54 \ mol \ H_2O*\frac{6.022 *10^{23}\ molecules \ H_2O}{1 \ mol \ H_2 O}[/tex]
When we multiply, the moles of water will cancel out.
[tex]8.54 *\frac{6.022 \ molecules \ H_2O}{1 \ }[/tex]
Since the fraction has a 1 as a denominator, we can remove it. The problem will be a simple multiplication problem.
[tex]8.54*6.022 \ molecules \ H_2O[/tex]
[tex]5.142788*10^{24} \ molecules \ H_2O[/tex]
The original measurement of 8.54 has 3 significant figures (8, 5, and 4). Therefore, we must round our answer to 3 sig figs, which is the hundredth place in this case.
The 2 in the thousandth place tells us to leave the 4 in the hundredth place.
[tex]5.14 *10^{24} \ molecules \ H_2 O[/tex]
There are about 5.14*10²⁴ molecules of water in 8.54 moles.
Answer:
5.14 x 10^24 molecules of H2O.
Explanation:
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