20.0cm³ of a sodium hydroxide solution containing 8.0g/dm³ were required for complete neutralization of 0.18g of a dibasic acid.Calcualate the relative molecular mass of the acid

Answer 1

To calculate the relative molecular mass of the acid, we need to use the equation:

Moles of acid = Moles of sodium hydroxide

First, let's calculate the moles of sodium hydroxide:

Moles = concentration (g/dm³) x volume (dm³)
Moles = 8.0g/dm³ x 20.0cm³ / 1000cm³ = 0.16 moles of sodium hydroxide

Since the acid is dibasic, it will react with two moles of sodium hydroxide. Therefore, the moles of acid can be calculated as follows:

Moles of acid = 0.16 moles of sodium hydroxide / 2 = 0.08 moles of acid

Next, we calculate the molar mass of the acid using the equation:

Relative molecular mass (g/mol) = mass (g) / moles

Rearranging the equation, we have:

Relative molecular mass = mass (g) / moles

Relative molecular mass = 0.18g / 0.08 moles = 2.25 g/mol

Therefore, the relative molecular mass of the acid is 2.25 g/mol.