Respuesta :

The weight percent formaldehyde in the pesticide sample if 37.49 of 0.2664 were needed to titrate the liberated base 24.218% .

Given mass of  sample = 37.49 g

Moles of HCl = ?

Molarity of HCl = 0.2664 M = 0.2664 mol/L

Volume of HCl = 37.49 ml = 37.49*10^-3 L

Moles = Molarity * Volume

Moles of HCl = 0.2664 (mol/L) *37.49*10^-3 L

                    = 9.987*10^-3 mol .

Neutralization reaction : moles of acid = moles of Base

Moles of Base = 9.987*10^-3 mol .

Moles of Formaldehyde = 9.987*10^-3 mol .

Atomic mass of H = 1 u

                         O = 16 u

                         C = 12 u

Molar mass of HCHO = 1+12+1+16 = 30 g/mol .

Moles = mass/molar mass

Mass of Formaldehyde = 9.987*10^-3 mol * 30 g/mol

                                     = 299.6*10^-3 g = = 0.2996 g .

Mass or weight percentage = Mass of Formaldehyde *100/Total mass of sample

Mass % = 0.2664*100/1.10 = 26.64/1.10 = 24.218% .

Learn more about weight percent  here:-https://brainly.com/question/7152617

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