A 22.709 g sample of impure magnesium carbonate was heated to complete decomposition
according to the equation
MgCO3(s) → MgO(s) + CO2(g).
After the reaction was complete, the solid
residue (consisting of MgO and the original
impurities) had a mass of 15.3018 g. Assuming that only the magnesium carbonate had
decomposed, how much magnesium carbonate was present in the original sample?
Answer in units of g
To find the amount of magnesium carbonate present in the original sample, we need to calculate the mass of MgCO3 that decomposed during the reaction. We can do this by subtracting the mass of the residue (MgO + impurities) from the mass of the original sample.
Given:
Mass of original sample (MgCO3 + impurities) = 22.709 g
Mass of residue (MgO + impurities) = 15.3018 g
Mass of MgCO3 that decomposed = Mass of original sample - Mass of residue
= 22.709 g - 15.3018 g
= 7.4072 g
Therefore, the amount of magnesium carbonate present in the original sample is 7.4072 g.
To calculate the amount of magnesium carbonate present in the original sample, we need to determine the mass of the magnesium carbonate that decomposed during the reaction.
The given information includes:
- Mass of the impure magnesium carbonate sample before decomposition: 22.709 g
- Mass of the solid residue after decomposition: 15.3018 g
To find the mass of the magnesium carbonate that decomposed, we need to subtract the mass of the solid residue from the initial mass of the sample:
Mass of magnesium carbonate decomposed = Mass of initial sample - Mass of solid residue
Substituting the values:
Mass of magnesium carbonate decomposed = 22.709 g - 15.3018 g
Calculating the difference:
Mass of magnesium carbonate decomposed = 7.4072 g
Therefore, the mass of magnesium carbonate present in the original sample was 7.4072 g.