When surface water dissolves carbon dioxide, carbonic acid (H2CO3) is formed. When the water moves underground through limestone formations, the limestone dissolves and caves are sometimes produced.
CaCO3(s) + H2CO3(aq) Ca(HCO3)2(aq)
What mass of limestone must have dissolved if 1.98 1010 kg of calcium hydrogen carbonate was produced?
!. Write and balance the equation. I note there is no arrow in your equation.
2. Convert grams calcium hydrogen carbonate to moles. moles. = grams/molar mass.
3. Using the coefficients in the balanced equation, convert moles in step 2 to moles of limestone.
4. Convert mols limestone to grams. grams = moles x molar mass.
Post your work if you get stuck.
To find the mass of limestone that must have dissolved, we need to convert the given mass of calcium hydrogen carbonate (Ca(HCO3)2) to the mass of limestone (CaCO3).
The balanced chemical equation tells us that 1 mole of calcium hydrogen carbonate (Ca(HCO3)2) is produced from 1 mole of limestone (CaCO3).
The molar mass of Ca(HCO3)2 is:
Ca = 40.08 g/mol
C = 12.01 g/mol
O = 16.00 g/mol
H = 1.01 g/mol
Adding up the molar masses:
Ca(HCO3)2 = 40.08 + (12.01 + 16.00 + (1.01 * 3)) * 2 = 162.11 g/mol
Now we can calculate the moles of calcium hydrogen carbonate:
Moles = Mass / Molar Mass
Moles of Ca(HCO3)2 = 1.98 * 10^10 kg / 162.11 g/mol
Moles of Ca(HCO3)2 = (1.98 * 10^10 * 10^3) / 162.11 mol
Assuming that each mole of Ca(HCO3)2 comes from one mole of CaCO3, we can conclude that the mass of limestone that must have dissolved is the same as the mass of calcium hydrogen carbonate.
Mass of limestone = Mass of Ca(HCO3)2
Mass of limestone = Moles of Ca(HCO3)2 * Molar Mass of CaCO3
Mass of limestone = [(1.98 * 10^10 * 10^3) / 162.11] * 100.09 g/mol
Calculating the result:
Mass of limestone = 1.219 * 10^11 kg
Therefore, approximately 1.219 * 10^11 kg of limestone must have dissolved to produce 1.98 * 10^10 kg of calcium hydrogen carbonate.
To find the mass of limestone that dissolved, we need to use the balanced chemical equation provided:
CaCO3(s) + H2CO3(aq) → Ca(HCO3)2(aq)
From the equation, we see that 1 mole of CaCO3 reacts with 1 mole of H2CO3 to form 1 mole of Ca(HCO3)2. Therefore, the molar ratio between CaCO3 and Ca(HCO3)2 is 1:1.
To determine the mass of limestone (CaCO3) that dissolved, we need to convert the given amount of calcium hydrogen carbonate produced (1.98 * 10^10 kg) to moles using its molar mass and then use the stoichiometry of the balanced equation.
The molar mass of Ca(HCO3)2 is:
(1 * atomic mass of Ca) + (2 * (atomic mass of H + atomic mass of C + 3 * atomic mass of O))
Calculating this gives us:
(1 * 40.08 g/mol) + (2 * (1.01 g/mol + 12.01 g/mol + 3 * 16.00 g/mol)) = 162.11 g/mol
Now we can calculate the number of moles of Ca(HCO3)2 using the given mass:
Number of moles = mass / molar mass
Number of moles = 1.98 * 10^10 kg / (162.11 g/mol)
To get the mass of CaCO3, we use the stoichiometric ratio of 1:1 between CaCO3 and Ca(HCO3)2. This means that the mass of CaCO3 is equal to the calculated mass of Ca(HCO3)2:
Mass of CaCO3 = mass of Ca(HCO3)2
Mass of CaCO3 = (1.98 * 10^10 kg / (162.11 g/mol)) g
You can now evaluate the above expression to find the mass of limestone (CaCO3) that dissolved.