How much energy is in a nut? Burn it and find out. The

Chapter 7, Problem 31TAD

(choose chapter or problem)

How much energy is in a nut? Burn it and find out. The heat from the flame is energy released when carbon and hydrogen in the nut combine with oxygen in the air (oxidation reactions) to produce \(\mathrm{CO}_{2}\) and \(\mathrm{H}_{2} \mathrm{O}\). Pierce a nut (pecan or walnut halves work best) with a bent paper clip that holds the nut above the table surface. Above this, secure a can of water so that you can measure its temperature change when the nut burns. Use about \(10^{3} \mathrm{~cm}\) (10 mL) of water and a Celsius thermometer. As soon as you ignite the nut with a match, place the can of water above it and record the increase in water temperature once the flame burns out. The number of calories released by the burning nut can be calculated by the formula \(Q=c m \Delta T\), where c is its specific heat \(\left(1 \mathrm{cal} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C}\right)\), m is the mass of water, and \(\Delta T\) is the change in temperature. The energy in food is expressed in terms of the Calorie, which is 1000 of the calories you’ll measure. So to find the number of Calories, divide your result by 1000. (See Think and Solve #36.)