If the SPF rating is 20 then it means it would provide 20 times the protection instead of no sunscreen and 20 times longer someone would take before the person started to burn or in this case 200 minutes.
Answer:
B. 0.075 m (NH4)3PO4
Explanation:
Our strategy here is to recall the van´t Hoff factor, i, for the colligative properties of electrolyte solutions which appears as the consequence that electrolytes disociate completely in their solutions in water.
Thus in this problem we need to determine i and then realize the one with the lowest freezing point will have the biggest i ( all the concentrations are equal) since
ΔTf = i m Kf
Substance van´t Hoff factor
Li I 2
(NH4)3PO4 4
NaIO4 2
KCN 2
KNO2 2
The correct answer is B. 0.075 m (NH4)3PO4
Answer: Cl2
Explanation: ionic compounds forms cations and anions in water solution.
HI is a weak acid and forms H+ and I- ions. Cl2 is dissolved slightly in water
And stays in molecule form which can not transfer charge like cations and anions.
