Answer :
Answer: The mass of magnesium carbonate that will be dissolved in the reaction is 6.99 g.
Explanation:
We are given:
Amount of heat released = 1950 J = 1.950 kJ (Conversion factor: 1 kJ = 1000 J)
The chemical equation for the reaction of magnesium carbonate and hydrochloric acid follows:
[tex]MgCO_3+2HCl\rightarrow MgCl_2+H_2O+CO_2;\Delta H_{rxn}=-23.4kJ[/tex]
By Stoichiometry of the reaction:
If 23.4 kJ of heat is released, then 1 mole of magnesium carbonate is dissolved
So, when 1.950 kJ of heat is released, then = [tex]\frac{1mol}{23.4kJ}\times 1.950kJ=0.083mol[/tex] of magnesium carbonate is dissolved
To calculate the mass of the substance by given number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Moles of magnesium carbonate = 0.083 moles
Molar mass of magnesium carbonate = 84.3 g/mol
Putting values in above equation, we get:
[tex]0.083mol=\frac{\text{Mass of magnesium carbonate}}{84.3g/mol}\\\\\text{Mass of magnesium carbonate}=0.083mol\times 84.3g/mol=6.99g[/tex]
Hence, the mass of magnesium carbonate that will be dissolved in the reaction is 6.99 g.