6.0g of impure and hydrous Na2SO4 were made up to 1dm^3 of solution neutralize 22.20cm^3 of 0.1mol/dm^3 of HCL.calculate:
a)concentration of Na2CO3 in mol/dm^3.
b)concentration of Na2CO3 in gram/dm^3.
c)percentage purity in carbon.
Please check your post. There is something wrong. First the wording is not clear; however,even if it were, there is no way to get Na2CO3 out of Na2SO4.xH2O
To calculate the concentration of Na2CO3 in mol/dm^3, concentration in gram/dm^3, and the percentage purity in carbon, we need to follow a series of steps:
Step 1: Determine the molar mass of Na2CO3
The molar mass of Na2CO3 can be calculated by summing up the atomic masses of each element in the compound:
Na: 22.99 g/mol (sodium)
C: 12.01 g/mol (carbon)
O: 16.00 g/mol (oxygen)
Molar mass of Na2CO3 = (2 × 22.99) + 12.01 + (3 × 16.00) = 105.99 g/mol
Step 2: Calculate the number of moles of Na2CO3 used to neutralize the HCl solution
Given that 22.20 cm^3 of 0.1 mol/dm^3 HCl were neutralized, we can convert the volume to dm^3:
22.20 cm^3 = 0.02220 dm^3
Since HCl and Na2CO3 react in a 1:1 stoichiometric ratio, this means that the number of moles of Na2CO3 is equal to the number of moles of HCl.
Number of moles of Na2CO3 = Number of moles of HCl = 0.1 mol/dm^3 × 0.02220 dm^3 = 0.00222 mol
Step 3: Calculate the concentration of Na2CO3 in mol/dm^3
The concentration of Na2CO3 in mol/dm^3 can be determined by dividing the number of moles of Na2CO3 by the volume of the solution (1 dm^3):
Concentration of Na2CO3 = 0.00222 mol / 1 dm^3 = 0.00222 mol/dm^3
Step 4: Calculate the concentration of Na2CO3 in gram/dm^3
To calculate the concentration in gram/dm^3, we need to consider the molar mass of Na2CO3:
Concentration of Na2CO3 in gram/dm^3 = Concentration of Na2CO3 in mol/dm^3 × Molar mass of Na2CO3
= 0.00222 mol/dm^3 × 105.99 g/mol
Step 5: Calculate the percentage purity in carbon
The percentage purity in carbon can be determined by comparing the amount of carbon in the impure sample to the amount of carbon in the pure Na2CO3. From the question, it is given that the impure sample contains Na2SO4, so we need to calculate the number of moles of carbon in Na2SO4.
The molar mass of Na2SO4 can be calculated as follows:
Na: 22.99 g/mol (sodium)
S: 32.07 g/mol (sulfur)
O: 16.00 g/mol (oxygen)
Molar mass of Na2SO4 = (2 × 22.99) + 32.07 + (4 × 16.00) = 142.04 g/mol
The molar mass of carbon is 12.01 g/mol.
Now, we calculate the percentage purity in carbon:
Percentage purity in carbon = (Molar mass of pure Na2CO3 / Molar mass of Na2SO4) × 100
Percentage purity in carbon = (12.01 g/mol / 142.04 g/mol) × 100