3.5.2: Practice with Heat and Temperature Calculations

Exercise \(\PageIndex{1}\)

Convert each Celsius temperature to Fahrenheit and to Kelvin.  Use correct significant digits.

a)  62.7 °C

b)  4.8 °C

c)  – 51.7 °C

Answer a

145 °F,  335.9 K 

Answer b

40.6 °F, 278.0 K

Answer c

– 61.1 °F, 221.5 K

Convert each Fahrenheit temperature to Celsius and to Kelvin.  Use correct significant digits.

d)  – 46.7 °F

e)  6.3 °F

f)  65 °F

Answer d

– 43.7 °C, 229.4 K

Answer e

– 14.3 °C, 258.9 K

Answer f

18 °C, 291 K

Exercise \(\PageIndex{1}\)

Convert each energy below.  [1 cal = 4.184 J exactly] [1 Cal = 1 kcal = 10³ cal]

a)  4.83 cal to J and to Cal

b)  657 J to cal and to kcal

c)  54.0 Cal to cal and to J

Answer a

20.2 J, 0.00483 Cal

Answer b

157 cal, 0.157 kcal

Answer c

54000 cal (or 5.40 x 10⁴ cal), 226000 J. (3 sig dig in each)

Exercise \(\PageIndex{1}\)

You find that it takes 261 J to raise the temperature of a piece of metal from 18.6 °C to 42.2 °C.  The mass of your metal is 28.72 g.  What is the specific heat of the metal?

Answer

0.385 J/g °C

Exercise \(\PageIndex{1}\)

How much energy is needed to raise the temperature of 65.8 g of aluminum from 22.0 °C to 47.8 °C?  The specific heat of aluminum is 0.214 cal/g°C.

Answer

363 cal (which is 1520 J)