Question

A reaction of 100mL of 1.35 M HCl and 100mL of 1.76 M NaOH is monitored and the following

Answer 1

Answer:  $\Delta H$ for the reaction is 87935 J

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

$Molarity=\frac{moles}{\text {Volume in L}}$

$moles of HCl$=$Molarity\times {\text {Volume in L}}=1.35\times 0.01=0.135moles$

$moles of NaOH$= $Molarity\times {\text {Volume in L}}=1.76\times 0.01=0.176moles$

As 1 mole of HCl neutralizes 1 mole of NaOH

0.135 moles of HCl will neutralize = 0.135 mole of NaOH

Thus HCl is the limiting reagent.

$Q=m\times c\times \Delta T=m\times c\times (T_{final}-T_{initial})$

Q = Heat absorbed by water = ?

m = mass of water = 200 g    (volume of water=200ml, density of wtaer = 1 g/ml)

c = specific heat capacity = $4.18 J/g^0C$

Initial temperature of water = = 24.6°C

Final temperature of water=  = 38.8 °C

$Q=200\times 4.18\times (38.8-24.6)$

$Q=11871.2J$

Thus heat released by 0.135 moles is = -11871.2 J

heat released by 1 mole is =$\frac{-11871.2 J}{0.135}\times 1=-87935J$