Questions

1) If one assumes that the specific heat of water doesn't change with temperature, what result

would you expect for part C? Calculate your % error based on this value and comment on

possible sources of error.

[0.5]

9

2) At 100°C, the heat capacity of water is actually 4.2157 J/g °C. Calculate your % error based on this

value.

[0.5]/n3) Assume that the density of water is 0.998 g/mL. Calculate the amount of water lost to

evaporation when you heated the water in part C.

[1]

4) Would having some of the water splash out when the metal was dropped into the

calorimeter erroneously increase or erroneously decrease the reported specific heat? Explain. [1]

5) There are 4,184 joules in a food Calorie (note the capital "C"). A 70.-gram serving of

Kraft® Macaroni and Cheese contains 16 grams of carbohydrate (4.0 Cal/g), 3.0 grams of fat (9.0

Cal/g), and 9.0 grams of protein (4.0 Cal/g). Calculate the temperature increase of 2.0 kg of water if

all of the food energy in 150.0 grams of Kraft Macaroni and Cheese goes entirely into heating

the water.

10/n6) When 49.834 grams of a metal at 100.0°C is added to 46.497 grams of water at 23.2°C,

the temperature of the water increases to 25.6°C. If the metal comes from the list below, what is

the identity of the metal?

[1]

Metal specific heat

Be

0.436 cal/g °C

brass

0.092 cal/g °C

Au

0.030 cal/g °C

Ag

Mg

Fe

0.056 cal/g °C

0.243 cal/g °C

0.108 cal/g °C