equivalent weight, molecular weight and formula for the unknown acid

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Dhamnekar Winod
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equivalent weight, molecular weight and formula for the unknown acid

Post by Dhamnekar Winod »

A solution of 3.15 g of an acid dissolved in 100 g of benzene boils at 80.985 ℃ ( the boiling point of pure benzene is 80.099 ℃). A 0.2145- g sample of the same acid requires 45.22 ml of a 0.1054 M of sodium hydroxide(NaOH) solution for complete neutralization. Complete combustion of 1.004 g of the acid produced 0.9817 g of CO2 and 0.2007 g of H2O.

(a) Calculate the equivalent weight of the acid.

(b)Calculate the molecular weight and molecular formula of the acid.

(c)Write an electron dot formula for the acid.

I am working on this question. Any chemistry help will be accepted.
Last edited by Dhamnekar Winod on Fri Mar 11, 2022 4:07 am, edited 1 time in total.
Any science consists of the following process. 1) See 2)Hear 3)Smell,if needed 4)Taste, if needed 5)Think 6)Understand 7)Inference 8)Take decision [Believe or disbelieve, useful or useless, true or false, cause or effect, any other criteria]
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ChenBeier
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Re: equivalent weight, molecular weight and formula for the unknown acid

Post by ChenBeier »

Answer is oxalic acid HOOC-COOH. Molar mass 90 g/ mol obtained by the boiling point difference of solution and solvent. Need ebullioscopic constant of Benzene 2,53 Kg K/mol for calculation

Combastion analysis gives ratio of C and H 1:1.

Neutralisation gives 4,766 mmol acid with the given mass it will be 45 g/ mol what means the acidity is the half of 90 g/ mol.
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Dhamnekar Winod
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Re: equivalent weight, molecular weight and formula for the unknown acid

Post by Dhamnekar Winod »

Correct answer.
Any science consists of the following process. 1) See 2)Hear 3)Smell,if needed 4)Taste, if needed 5)Think 6)Understand 7)Inference 8)Take decision [Believe or disbelieve, useful or useless, true or false, cause or effect, any other criteria]
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