(c) NH 3 + HCl

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volume molarity

mass specific heat ∆∆T C T

'

''' '

rxn sol n

sol n sol n sol n calorimeter sol n

#

###

=

-+

q

^ h _ i ^^hh

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..../.

0 0500 2 0

100 4 18 33 1 23 0 13 6 10 1

L mole L

gsol n' J/g C C C J C C

#

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=

: % ``%%-+jjD % %

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00500 2 0

44 10 44

L mol L

(^3) J kJ mol

= - # =-

3. Write the net ionic equation, including the ∆H’s, for the first two reactions studied and
   rearrange the equation(s) where necessary to produce the third reaction and its ∆H.

HOH HO()+-aq+ ()aq" (^2) ]gl ∆H = −54 kJ ⋅mol–1
NH (^32) ]aqg++H O]lg"NH 4 +]aqg OH-]aqg ∆H = +5.2 kJ ⋅mol–1
NH (^3) ]gaq +H()++aq"NH 4 ()aq ∆H =−49 kJ ⋅mol–1

4. Calculate the percent error between the measured ∆H and the calculated ∆H.

%%%%exp

exp

error

obs

(^10049)
44 49
##= - 100 10

= =-

• ^h

Laboratory Experiments