Answer:
168°C is the melting point of your impure sample.
Explanation:
Melting point of pure camphor= T =179°C
Melting point of sample =
= ?
Depression in freezing point = 
Depression in freezing point is also given by formula:

= The freezing point depression constant
m = molality of the sample = 0.275 mol/kg
i = van't Hoff factor
We have:
= 40°C kg/mol
i = 1 ( non electrolyte)




168°C is the melting point of your impure sample.
<span>The ends of a bar magnet are called POLES</span>
-2 cuz 20 negative minus 18 positive is -2
Answer:
occur if two of the ions form an insoluble ionic compound, which precipitates out of solution
Explanation:
When two ionic compounds are dissolved in water, a double replacement reaction takes place if two of the ions form an insoluble ionic compound, which precipitates out of solution. In double displacement reaction ions switch partners. And hence, produce an insoluble precipitate.