Question

4.The reaction of 0.25 g magnesium with 100.0 mL of 2 M hydrochloric acid (density d = 1.039 g/ml) raises the temperature of the solution from 20.0 °C to 35.0 °C. The specific heat for HCl is 3.98 J/(g.C). Mg(s) + 2HCl(aq) —> MgCl2(aq) + H2(g) Calculate the heat of the reaction. (Use the equation Q = s . m .ΔT where s is the specific heat, m is the mass of solution and ΔT is the change in temperature)

Answer 1

`Q=450.14J`

Step-by-step explanation:

Hello,

In this case, for the given equation to compute the heat, we should compute the mass of the solution of hydrochloric acid, thus, the first step is to compute its reacting mass:

`m_(HCl)^(reacting)=2(mol)/(L)*0.1000L *(36.45g)/(1mol)=7.29g`

Then, we obtain the total mass of the formed solution:

`m=0.25g+7.29g=7.54g`

In such a way, we can infer that the specific heat of the solution is mainly the specific heat of hydrochloric acid, therefore the heat turns out:

`Q=3.98(J)/(g\°C) *7.54g*(35.0\°C-20.0\°C)\\\\Q=450.14J`

Regards.