What would be causes of a lower experimentally calculated enthalpy compared to the accepted enthalpies in a Hess'

A . Naolt (s, - Naolt cag)
B. Na Olt cs + HCL cag)
Naclrags + 1,0 ( 1 )
C . Naolt cag) + HCC rags
-
Nacl lag ) + H, 0 10 )
Accepted
Value obtained from one - lab
Experimental value
Reaction
- 44 hJ/mol
- 40. 3 KJ / mol
Reaction B
- 100: 13 Ku / mol
- 82 . 3 KJ / mol
Reaction C
56. 13 KJ / mol
- 44. 3 KJ / mol
Reaction A
= - 40.3kJ/mol - (- 44 KJ / mol) x 100 = 3.7,100 = - 8.4 10
- 44 kJ / mol
- 44
Reaction B
= - 82 . 3 KJ /md - (- 100. 13 k / mo ) x 100 = 17. 83 x 100 - - 17. 81 %
- 100. 13 hJ / mol
- 100. 13
Reaction C
= - 44 . 3 kJ /mol - ( - 56. 13 k J / mol) x 100 = 11. 83,10 - 21. 08 /0
-56-13 hJ / mol
-56. 13