<span>The density of the solution =1.05 g/ml.
</span><span>The total mass of the resulting solution is = 398.7 g (CaCl2 + water)
</span>
Find moles of CaCl2 and water.
Molar mass of CaCl2 = 110 (approx.)
Moles of CaCl2 = 23.7 / 110 = 0.22
so, moles of Cl- ion = 2 x 0.22 = 0.44 (because each molecule of CaCl2 will give two Cl- ions)
Moles of water = 375 / 18 = 20.83
Now, Mole fraction of CaCl2 = (moles of CaCl2) / (total moles)
total moles = moles of Cl- ions + moles of Ca2+ ions + moles of water
= 0.44 + 0.22 + 20.83
=21.49
So, mole fraction = 0.44 / (21.49) = 0.02
Guess what !!! density is not used. No need
This question is asking for an element with 5 valence electrons. Just go to the row it is in (excluding transition metals) and count over.
The answer would be c. P
Taking into account the definition of molarity, the concentration of the solution is 0.855 
.
<h3>Definition of molarity</h3>
Molar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:
Molarity is expressed in units .
<h3>Molarity of NaCl</h3>
In this case, you have:
- number of moles of NaCl=
1.71 moles (being 58.45 g/mole the molar mass of NaCl) - volume 2 L
Replacing in the definition of molarity:
Solving:
Molarity= 0.855
Finally, the concentration of the solution is 0.855 .
Learn more about molarity:
<u>brainly.com/question/9324116</u>
<u>brainly.com/question/10608366</u>
<u>brainly.com/question/7429224</u>
Mixing water and sugar is a physical change. A physical change is just a change in the form of the substance, whereas a chemical change is when the substance itself changes… chemically. An easy way to figure out which is which is trying to "undo" the change. If it can be undone, it is physical.
20 grams of borax contains (20.0g) / (201 g mol -1) =0.10 mol of borax.
Therefore 0.40 mol of borax
