The biggest source of vitamin D is the sun.
Both "<span>Do high pressure systems prefer forming in Ecuador compared to in Springdale?" and </span>"<span>Are average yearly temperatures in Ecuador greater than in Springdale?" are acceptable questions. The others deal with subjectivity. </span>
The answer is 5.32 × 10²³ molecules
<span>Avogadro's number is the number of units (atoms, molecules) in 1 mole of substance:
</span>6.023 <span>× 10²³ units per 1 mole
We have 0.883 moles.
If 1 mole has </span>6.023 × 10²³ molecules, 0.883 moles will have x molecules:
1 mole : 6.023 × 10²³ molecules = 0.883 moles : x
x = 6.023 × 10²³ molecules * 0.883 moles : 1 mole = 5.32 × 10²³ molecules
First figure out how many grams must freeze and then convert the grams to moles.
<span>Hf = -334 J/g. Convert this to KJ/g by dividing by 1000. (There are 1000 Joules in a kJ). </span>
<span>Hf = -334 J/g ÷ 1000 J/kj = -0.334 kJ/g </span>
<span>Now, divide 100 kJ by -0.334 kJ/g (see how the units are lining up?) </span>
<span>100 kJ ÷ -0.334 kJ/g = 299 g </span>
<span>Now convert this to moles by dividing by the molecular weight of water (18.0g/mole). </span>
<span>299 ÷ 18.0 = 16.6 moles </span>
