Neco Model Questions Vol1 2020 Chemistry Question 4

Practice practical question 4 from the 2020 Neco Model Questions Vol1 Chemistry examination. This question covers Mole Concept .

Neco Model Questions Vol1 2020 Chemistry Practical

Topic: Mole Concept

Question 4 NECO_MODEL_QUESTIONS_VOL1 • 2020 • CHEMISTRY • practical

A 0.250 g sample of an unknown monoprotic solid acid (theoretical molar mass = 120 g·mol⁻¹) is dissolved in 250.0 mL of distilled water. The solution is titrated with 0.1000 M NaOH using phenolphthalein as the indicator. The endpoint is reached after 25.00 mL of the NaOH solution has been added.

Question Parts

( a )

Write the balanced chemical equation for the neutralisation reaction between the unknown acid (HA) and NaOH.

( b )

Calculate the number of moles of NaOH used and hence the number of moles of the unknown acid that reacted.

( c )

Determine the experimental molar mass of the unknown acid.

( d )

Calculate the percent purity of the sample, assuming the only impurity is inert.

( e )

Identify two possible sources of error in this titration and suggest a method to minimise each error.

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About This Question

This is Neco Model Questions Vol1 2020 Chemistry Question 4. It is one of the practical questions from the 2020 Neco Model Questions Vol1 Chemistry examination.

The question covers Mole Concept .

View More Neco Model Questions Vol1 2020 Chemistry Questions More Neco Model Questions Vol1 Practice Questions Back to Questions

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