Suppose 200.0 ml of 1.00 m hcl and 200.0 ml of 1.00 m naoh, both initially at 21.0°c, are mixed in a thermos flask. when the reaction is complete, the temperature is 27.8°c. assuming that the solutions have the same heat capacity as pure water, compute the heat released (in kj).

-11.4 kJ of heat are released

Explanation:

Balanced reaction-

According to balanced equation, 1 mol of HCl is neutralized by 1 mol of NaOH.

So, 200 mL of 1 M HCl will be completely neutralized by 200 mL of 1 M NaOH.

Let's assume both HCl and NaOH solutions have densities equal to density of pure water.

We know, density = (mass)/(volume)

Density of pure water = 1 g/mL

So mass of both solutions = = 200 g

So, mass of mixture = (200+200) g = 400 g

Hence, Amount of heat released =

Where, m represents mass, C represents heat capacity and represents change in temperature

Let's assume that heat capacity of mixture is also equal to heat capacity of water.

Heat capacity of water = 4.186 J/(g.)

So, amount of heat released = = J=11.4 kJ

As acid-base neutralization reactions are exothermic therefore-

Heat released = -11.4 kJ