QUESTION NOâ€‹ 22 22 When 1 g of anhydrous oxalic acid is burnt at 25 C, the amount - Chemistry - Thermodynamics and Thermochemistry

Question

QUESTION NOâ€‹ 22

22   W h e n   1   g   o f   a n h y d r o
u s   o x a l i c   a c i d   i s   b u r n t
  a t   25 ° C ,   t h e   a m o u n t
  o f   h e a t   l i b e r a t e d   i s
  2 835   k J   ∆ H   c o m b u s t i o n
  i s   ( o x a l i c   a c i d   :   C 2
H 2 O 4 )   ( 1 )   - 255 15   k J    
                 
                 
                 
                 
  ( 2 )   - 445 65   k J ( 3 )   - 295 24
  k J                
                 
                 
                 
        ( 4 )   - 155 16   k J

Vartika Jain · Accepted Answer

Dear Student,

As per definition, Heat of Combustion of a substance is the heat
liberated when 1 mole of the substance undergoes complete
combustion with oxygen at constant pressure

molar mass of H2C2O4 is 90 03 g
mol−1

1g of anhydrous oxalic acid is burnt at 25 °C , the amount of
heat liberated is 2 835 kJ

then when 90 03 g of anhydrous oxalic acid is burnt at 25 °C ,
the amount of heat liberated is 2 835 x 90 03= 255 23
kJ

So heat of Combustion is 255 23
kJ/moleâ€‹

Hence, correct answer is (1)