Answer : The change in boiling point is, 
Explanation :
Formula used :

where,
= change in boiling point = ?
i = Van't Hoff factor = 3 (for MgI₂ electrolyte)
= boiling point constant for water = 
m = molality = 0.615 m
Now put all the given values in this formula, we get


Therefore, the change in boiling point is, 
He has to use a different colored light at a higher frequency.
Also water H2O is made of H+ and OH- ions. so when an acidic substance is added to water the concentration of H+ ions increase.