contestada

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).

Respuesta :

Answer:

-11.4 kJ of heat are released

Explanation:

Balanced reaction- [tex]HCl+NaOH\rightarrow NaCl+H_{2}O[/tex]

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 = [tex](200\times 1)g[/tex] = 200 g

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

Hence, Amount of heat released = [tex](m_{mixture}\times C_{mixture}\times \Delta T_{mixture})[/tex]

Where, m represents mass, C represents heat capacity and [tex]\Delta T[/tex] 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.[tex]^{0}\textrm{C}[/tex])

So, amount of heat released = [tex][400g\times 4.186J.g^{-1}.^{0}\textrm{C}^{-1}\times(27.8-21.0)^{0}\textrm{C} ][/tex] = [tex]1.14\times 10^{4}[/tex]J=11.4 kJ

As acid-base neutralization reactions are exothermic therefore-

Heat released = -11.4 kJ

Otras preguntas