a) Molar mass of Calcium Carbonate:
CaCO3
Molar mass of:
Ca - 40 g/mol
C - 12 g/mol
O - 16 g/mol
We need to multiply the molar mass of each atom by the quantity of this element in the molecular formula, and then sum the results:
(1*40) + (1*12) + (3*16) = 100 g/mol
Answer a): 100 g/mol
b) To find the mass of 18.18 moles of a sample of CaCO3, we need to use the following formula: mass = moles * molar mass
mass = 18.18 * 100
mass = 1,818 g of CaCO3
We need to transform to Kg, so we just divide the result by 1000:
1.818 Kg
Answer b): 1.818 Kg of CaCO3
c) First, let's write the equation of dissociation of CaCO3:
CaCO3 -> Ca^2+ + CO3^2-
So 1 mol of CaCO3 produces 1 mol of CO3^2-
Now let's transform 18.18 g of CaCO3 into moles using the following formula: moles = mass/molar mass
moles = 18.18/100
moles = 0.1818
As we find before, 1 mole of CaCO3 produces 1 mole of CO3^2-
So 0.1818 moles of CaCO3 produces 0.1818 moles co CO3^2-
Let's find the mass of CO3^2- using the following formula:
mass = moles x molar mass
molar mass of CO3^2- = 60 g/mol
mass = 0.1818 x 60
mass = 10.908 g
Answer c): 10.908 g