Magnesia (MgO(s)) is used for fire brick, crucibles and furnace linings because of its high melting point. It is produced by decomposing magnesite (MgCO3(s)) into at around 1200oC
Write a balanced equation for the magensite decomposition being sure to include states for the species.
I thought it was:
MgCO3(s) ...> MgO (s) + CO2(g)
but it was marked wrong.
help..thank you.•Chemistry - DrBob222, Monday, November 9, 2015 at 12:46am
Probably I would have marked it right; it may be that you omitted the heat sign over the arrow OR the word "heat" on the left side.
It said hint:
When MgCo3 decomposes, MgO is one of the products. What is the other product? what formula could you use to calculate the change in enthalpy for a reaction if you had access to the molar enthalpies for each of the reactants and products? How could you use a similar strategy to calculate the change in enthalpy for a reaction?
thank you, Dr, BOB
To write the balanced equation for the decomposition of magnesite (MgCO3(s)), you need to include the correct formula and state for the other product formed. The balanced equation is:
MgCO3(s) → MgO(s) + CO2(g)
Make sure to include the heat sign (Δ) above the arrow to indicate that the reaction is endothermic and requires heat to occur.
The balanced equation for the decomposition of magnesite (MgCO3) is:
MgCO3(s) → MgO(s) + CO2(g)
To balance the equation, you need to make sure that there are an equal number of atoms of each element on both sides of the equation. In this case, we have:
1 Mg on both sides
1 C on both sides
3 O on both sides
So the equation is already balanced. However, it is important to note that this reaction occurs with the application of heat. So the equation should include either the heat sign (Δ) or the word "heat" on the left side of the equation. The final equation should be:
Δ or heat:
MgCO3(s) → MgO(s) + CO2(g)
Make sure to include the state of matter (s for solid and g for gas) for each of the species in the equation.
Regarding the hint, the other product of the decomposition reaction is carbon dioxide (CO2). The formula that could be used to calculate the change in enthalpy for a reaction is ΔH = ΣΔH(products) - ΣΔH(reactants). This formula calculates the change in enthalpy (ΔH) by subtracting the sum of the enthalpies of the reactants (ΣΔH(reactants)) from the sum of the enthalpies of the products (ΣΔH(products)).
To calculate the change in enthalpy for a reaction, you would need to know the molar enthalpies (ΔH) for each of the reactants and products involved in the reaction. By substituting these values into the formula, you can determine the change in enthalpy for the reaction.
Similarly, to calculate the change in enthalpy for a different reaction, you would follow the same strategy. Determine the molar enthalpies for each reactant and product, substitute these values into the formula, and calculate the change in enthalpy.