CHM 1025C/CHM 1032C/CHM 2045C Module 2 Name: __________

Part I: Heat and Specific Heat 10 points Sample Test

 

Find the specific heat of gold if 25.0 cal is required to heat 30.0 g of gold from 27.7 oC to 54.9 oC.

 

Specific heat is the amount of heat required to raise the temperature of one gram of a substance one degree Celsius.

 

Heat (cal)

 

 

(

cal

)

----------------------------------------------------

=

Specific Heat (C)

--------

Mass (g) ∙ Temperature Change (∆t)

 

 

g ∙ oC

q = C ∙ m ∙ ∆t

 

∆t = 54.9 oC 27.7 oC = 27.2 oC

 

 

 

25.0 cal

 

 

 

 

(

cal

)

-----------------------

=

Specific Heat

=

0.0306

--------

30.0 g ∙ 27.2 oC

 

 

 

 

g ∙ oC

 

 

 

Calculate the heat required to raise to raise 25.0 g of iron (sp Heat=0.108 cal/g ∙ oC) from 25.0 oC to 50.0 oC.

 

q = C ∙ m ∙ ∆t

 

q = (0.108 cal/g ∙ oC) (25.0 g) (50.0 oC 25.0 oC )

 

q = 0.108 ∙ 25.0 ∙ 25.0 cal

 

q = 67.5 cal

 

 

Text References:

 

McMurry 6th 1032C text: Chapter 2 Section 2.10 see woirked example 2.13 page 38, then try problems 2.20 and 2.21 page 39. End of Chapter page 46 Problems 2.64-2.71.

 

Corwin 5th CHM 1025C text Chapter 3 Section 3.9 see worked example 3.19 page 64; then try the practice exercise on page 64. Additional problems end of chapter page 69: #57-#64.