If 0.1200g of sodium carbonate is dissolved in 50 mL of water and titrated with 0.1000 M HCl, how many mL of HCl will be required to reach the second endpoint?
CO3^-2 + H^+1 --> HCO3^-1
HCO3^-1,+ H^+1 --> H2CO3
Na2CO3 + 2HCl ==> 2NaCl + H2O + O2
Method A.
Convert 0.1200 g Na2CO3 to moles. moles = grams/molar mass.
Using the coefficients in the balanced equation, convert moles Na2CO3 to mols HCl. That will be 2x moles Na2CO3.
M HCl = moles HCl/L HCl, solve for L HCl and convert to mL.
Method B.
Convert 0.1200 g Na2CO3 to moles.
Using the equation to add the first H to Na2CO3, we have
Na2CO3 + HCl ==> NaCl + NaHCO3
Using the coefficients, convert moles Na2CO4 to moles HCl. In this case moles Na2CO3 are same as moles HCl.
Then M HCl = moles HCl/L HCl and convert to mL.
Finally, since this is the mL to add 1 H, then 2x that will be mL to add both H. Method A and method B will give the same answer.
To determine how many mL of HCl will be required to reach the second endpoint, we need to understand the reaction that takes place between sodium carbonate (Na2CO3) and HCl.
The balanced equation for the reaction is as follows:
Na2CO3 + 2HCl → 2NaCl + H2O + CO2
To calculate the number of moles of sodium carbonate (Na2CO3) used in the reaction, we need to convert the given mass (0.1200g) to moles.
The molar mass of Na2CO3 is:
(2 x atomic mass of Na) + atomic mass of C + (3 x atomic mass of O)
= (2 x 22.99 g/mol) + 12.01 g/mol + (3 x 16.00 g/mol)
= 105.99 g/mol
To convert grams to moles, we use the formula:
moles = mass / molar mass
moles of Na2CO3 = 0.1200g / 105.99 g/mol
Next, we need to determine the concentration of HCl (hydrochloric acid) in units of moles per liter (M). The given concentration is 0.1000 M, which means there are 0.1000 moles of HCl in 1 liter of solution.
Now, we can use stoichiometry to determine the mole ratio of HCl to Na2CO3 in the balanced equation. From the equation, we can see that 1 mole of Na2CO3 reacts with 2 moles of HCl.
Since we know the mole ratio and the moles of Na2CO3, we can calculate the moles of HCl required for the reaction.
moles of HCl = moles of Na2CO3 x (2 moles HCl / 1 mole Na2CO3)
Now that we know the moles of HCl required for the reaction, we can determine the volume in liters (L) by dividing the number of moles of HCl by the concentration of HCl (given as 0.1000 M).
volume of HCl (in L) = moles of HCl / concentration of HCl
Finally, we need to convert the volume of HCl from liters to milliliters (mL) because the given question asks for the volume in milliliters.
volume of HCl (in mL) = volume of HCl (in L) x 1000
By following these steps, you should be able to calculate the volume of HCl required to reach the second endpoint.