Question

1ml of corn syrup is fully combusted in a calorimeter containing 200 ml of water. the temp of the water changes from 20 C to 33.6 C.

a) if the density of corn syrup is .966 g/ml, what is the caloric content of corn syrup in kcal?

b) what type of solid is fructose and what interactions hold it together?

c) write balanced equation for the combustion of fructose.

Answer 1

Given that

Volume of the corn syrup = 1 mL

Density of corn syrup = 0.966 g/mL

Mass of 1 mL corn syrup = 0.966 g/mL * 1 mL

= 0.966 g

Volume of water = 200 mL

We know that density of water = 1g/mL

Mass of 200 mL of water = density* Volume

= 200 mL * 1 g/mL = 200 g

Amount of heat absorbed or evolved is given by

Q = mC∆T

Where m = mass of substance

C is the specific heat capacity of the substance

∆T = Change in temperature = T​​​​​​f - T​​​​​i​​​

For water C = 4.184 J/(g-°C)

m = 200 g

Given that temperature is increased from 20°C to 33.6°C,

∆T = 13.6°C

Amount of heat absorbed by 200 mL of water =

200 g * 4.184 J/(g-°C) * 13.6°C

= 11,380.5 J = 11.381 kJ

4.184 J = 1 Calorie

11,380.5 J = ? Calories

= 11380.5 J * 1 Cal/4.184 J

= 2720 Cal = 2.720 kCal

Calorific content of substance is the amount of heat liberated by burning of 1g of substance.

Amount of heat absorbed by water is equal to the amount of heat liberated by the corn syrup.

0.966 g of corn syrup releases 2.720 kCal of heat

1 g releases ? kCal of heat

= 1 g *2.720 kCal/0.966 g

= 2.82 kCal/g

Calorific content of corn syrup = 2.82 kCal/g

b)

Molecular formula of Fructose is C6H12O​6

It is a covalent solid. The bonds present in fructose are covalent bonds.

The vandewaal forces or London dispersion forces are molecular forces hold fructose together.

C) Combustion reaction is the reaction in which a compound is burnt in excess of air

Combustion of fructose is written as