enthalpy change
posted by Mikky on .
a bunsen burner flame takes 8 minutes to raise 250g of water from 20 degrees to 100 degrees celcius, when the water is in a beaker of mass 100g (c=0.67J/g degrees celcuius). How long will i take to raise the temperature of 200g of glycerin (c=2.43J/g degrees celcius) contained in the same beaker from 20 to 80 degrees celcius?

The heat required to raise the beaker temperature will be 3/4 as much the second time, becasue of the deltaT rTIO. The heat required to heat the liquid will be higher by a factor (200/250)(2.43/0.67) = 2.90
Calculate the total heat required in the second case. The ratio (heat)2/(heat1) wilL be the ratio of the heating times required, assuming the heaT transfer rate of the burner is the same. 
i don't get this, could you explain in details or could u tell me the ans. so i could verify my answer. thanks