A chemistry student weighs out
0.0294g
of sulfurous acid
H2SO3
, a diprotic acid, into a
250.mL
volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with
0.2000M
NaOH
solution.
To find the molar mass of H2SO3, we need to determine the molar masses of the individual elements in the compound and add them up.
The molar mass of hydrogen (H) is approximately 1.01 g/mol.
The molar mass of sulfur (S) is approximately 32.07 g/mol.
The molar mass of oxygen (O) is approximately 16.00 g/mol.
Since H2SO3 has two hydrogen atoms, one sulfur atom, and three oxygen atoms, we can calculate the molar mass as follows:
(2 * 1.01 g/mol) + (1 * 32.07 g/mol) + (3 * 16.00 g/mol) = 62.09 g/mol
Therefore, the molar mass of H2SO3 is 62.09 g/mol.
Next, let's work on calculating the number of moles of H2SO3 in 0.0294g of the compound.
Number of moles (n) is calculated using the formula:
n = mass / molar mass
Substituting the values:
n = 0.0294g / 62.09 g/mol = 0.000473 mol
The student then plans to titrate the sulfurous acid with 0.2000M NaOH solution. The concentration of NaOH is given as 0.2000 moles per liter (Molarity = moles/liters).
Now, let's calculate the volume of the NaOH solution required for the titration.
Volume (V) is calculated using the formula:
V = n / C
Where n is the number of moles and C is the concentration.
Substituting the values:
V = 0.000473 mol / 0.2000 mol/L = 0.00237 L
Since the volume of the NaOH solution is given in liters, we can convert it to milliliters (mL) by multiplying by 1000:
V = 0.00237 L * 1000 mL/L = 2.37 mL
Therefore, the student will need approximately 2.37 mL of the 0.2000M NaOH solution to titrate the 0.0294g of sulfurous acid in the 250 mL volumetric flask.