The formula for mole fraction is:
-(1)
The solubility of oxygen gas = 1.0 mmol/L (given)
1.0 mmol/L means 1.0 mmol are present in 1 L.
Converting mmol to mol:

So, moles of oxygen = 0.001 mol
For moles of water:
1 L of water = 1000 mL of water
Since, the density of water is 1.0 g/mL.


So, the mass of water is 1000 g.
Molar mass of water = 18 g/mol.
Number of moles of water = 
Substituting the values in formula (1):


Hence, the mole fraction is
.
Explanation:
For example, Identify the number and type of ions formed in a reaction of calcium and carbon. Step 1: Determine the number of valence electrons for each element and whether the element loses or gains electrons. Calcium has 2 valence electrons and is a metal so it will give up two electrons.
The density of the rectangular block in g/mL is 7.0.
<u>Given the following data:</u>
- Mass of block = 22.8 gra1.94 kg
- Length of block = 3.21 cm
- Height of block = 1.84 in.
To find the density of the block in g/mL:
First of all, we would determine the volume of the rectangular block by using the following formula:
×
× 
<u>Conversion:</u>
1 in = 2.54 cm
5.83 in = X cm
Cross-multiplying, we have:

×
× 
Volume = 277.16 cubic centimeters.
<u>Note</u>: Milliliter (mL) is the same as cubic centimeters.
1000 grams = 1 kg
Y grams = 1.94 kg
Cross-multiplying, we have:
Y = 1940 grams
Now, we can find the density:

<em>Density </em><em>= 7</em><em>.0 g/mL</em>
Therefore, the density of the rectangular block in g/mL is 7.0.
Read more: brainly.com/question/18320053
Answer:
C.
Explanation:
The mass of the reactants should not change, in fact it would be equal because the only thing that changes is the form in which your products are in. The reactants will still have the same amount of mass from the products as no products were removed or added, the structure changed, the mass did not.