I think I've calculated the enthalpy right.. would anyone mind checking it?
(i) number of moles of HCL1000cm3 HCL solution contain 1mol of HCL
Number of moles of HCL= MV/1000
M= molarity of the solution (mol dm-3)
V= volume of the solution (cm3)
(2 x 100)/1000= 0.2 mol
(ii) number of moles of Na2CO3n= m/M
m= given mass (g)
M= molar mass(g mol-1)
M= (2 x 22.99) +(1 x 12.01) + (3 x 16.00)= 105.99 g mol-1
N= 8/105.99= 0.075 moles (3 s.f)
The ratio is 2 :1 so which means Na2CO3 is the limiting reactant.
(iii) Delta temperatureTFINAL-TINITIAL
25.0 ˚C - 20.0 ˚C= 5.0˚C (±1 ˚C)
(iv) Heat released during reactionQ= mc ΔT
m= 100 cm3= 100 ml
Density of water = 1g mol
So in 100ml, its 1g mol x100ml = 100g
(100g)(4.18 J/K.C)(5.0˚C)= 2090 Joules
Q= 2.09 kJ
ΔH= Q/mols
ΔH= 2.09/(0.075 )= 27.87 kJ/ mol Na2CO3
um is this also an endothermic reaction?