A 100.0 mL of 0.500 M HBr at 20.29 oC is added to 100.0 mL of 0.500 M KOH (also at 20.29 oC). After mixing, the temperature rises to 23.65 oC. Calculate the heat of this reaction. [assuming the density and specific heat of HBr and KOH is the same as water, 1.0 g/mL; 4.18 J/g oC, and the volume of the solution is additive].

Respuesta :

Answer : The heat of this reaction will be, 2.81 kJ

Explanation :

First we have to calculate the mass of water.

[tex]\text{Mass of water}=\text{Density of water}\times \text{Volume of water}[/tex]

Given:

Density of water = 1.0 g/mL

Volume of water = 100.0 mL + 100.0 mL = 200.0 mL

[tex]\text{Mass of water}=1.0g/mL\times 200.0mL[/tex]

[tex]\text{Mass of water}=200.0g[/tex]

Now we have to calculate the heat of this reaction.

Formula used :

[tex]q=m\times c\times (T_{final}-T_{initial})[/tex]

where,

q = heat = ?

m = mass of water = 200.0 g

c = specific heat of water = [tex]4.18J/g^oC[/tex]

[tex]T_{final}[/tex] = final temperature = [tex]23.65^oC[/tex]

[tex]T_{initial}[/tex] = initial temperature = [tex]20.29^oC[/tex]

Now put all the given values in the above formula, we get:

[tex]q=200.0g\times 4.18J/g^oC\times (23.65-20.29)^oC[/tex]

[tex]q=2808.96J=2.81kJ[/tex]

Thus, the heat of this reaction will be, 2.81 kJ