A 2.446-g sample thought to contain only one volatile substance, MgCO3, was heated in a nitrogen atmosphere for 30 min. After cooling, the residue weighed 2.216 g. Calculate the percentage of magnesium carbonate in the sample.
MgCO3 ==> MgO + CO2
Wt loss on heating = mass CO2 = 2.446 - 2.216 = 0.230g CO2
Convert to moles. moles = grams/molar mass
moles CO2 = moles MgCO3 in the sample.
g MgCO3 in the sample = moles MgCO3 x molar mass MgCO3
%MgCO3 = (mass MgCO3/mass sample)*100 = ?
Thanks DrBob222 :)
The answer is 18.01% :))
Whoa, hold your magnesium horses! We're diving into some chemistry here. Let me calculate the percentage of magnesium carbonate, but fair warning, there might be a little bit of clowning around along the way.
First, we need to find the weight loss during the heating process. Okie-dokie, let's subtract the residue weight (2.216 g) from the initial sample weight (2.446 g):
2.446 g - 2.216 g = 0.23 g
Now, this weight loss is due to the evaporation of magnesium carbonate into thin air! How rude! But we can use this loss to determine the percentage.
Let's divide the weight loss by the initial sample weight and multiply by 100 to get the percentage, shall we?
(0.23 g / 2.446 g) * 100 = 9.4%
So, the percentage of magnesium carbonate in the sample is approximately 9.4%. That's quite a bit of carbonation!
Remember, though, my calculations might be funny, but the chemistry is real.
To calculate the percentage of magnesium carbonate in the sample, we need to determine the mass of the magnesium carbonate in the initial sample and then convert it to a percentage.
First, let's find the mass of the magnesium carbonate in the sample by subtracting the mass of the residue from the initial mass of the sample:
Mass of magnesium carbonate = Initial mass of the sample - Mass of the residue
= 2.446 g - 2.216 g
= 0.230 g
Now, we can calculate the percentage of magnesium carbonate in the sample using the following formula:
Percentage of magnesium carbonate = (Mass of magnesium carbonate / Initial mass of the sample) * 100
Percentage of magnesium carbonate = (0.230 g / 2.446 g) * 100
= 9.4%
Therefore, the percentage of magnesium carbonate in the sample is approximately 9.4%.