Quiz 4 : Gravimetry and Volumetry Analysis

To prepare a solution of accurately known volume, a chemist should use a

• measuring cylinder

• beaker

• concial flask

• volumetric flask

A standard solution is a solution with accurately known concentration.

• True

• False

The point in an acid-alkali titration at which the reactants just react completely with each other is called the __________ point.

• end point

• equivalence point

__________ is a suitable indicator for the titration of a strong acid and a weak alkali.

• Methyl orange

• Phenolphthalein

• Litmus solution

• Universal indicator

During titration process, the end point and the equivalence point always occur at the same time.

• True

• False

20 cm³ of 1 mol dm^–3 CH₃COOH(aq) and 10 cm³ of 1 mol dm^–3 H₂SO₄(aq) require the same number of moles of NaOH for complete neutralization.

• True

• False

Solid sodium hydroxide CANNOT be weighed accurately for preparing a standard solution because

• it is corrosive.

• it decomposes easily.

• it is volatile.

• it absorbs moisture from the air.

25.0 cm³ of sodium hydroxide solution is tritrated against 0.2 mol dm^–3 hydrochloric acid until the indicator just changes colour. 27.5 cm³ of the acid are required to reach the end point.

Phenolphthalein is used as an indicator in the above experiment. What will be its colour change at the end point?

• From red to yellow

• From red to colourless

• From yellow to colourless

• From yellow to red

Whats a conjugate acid-base pair, according to Brønsted-Lowry theory.

• Differ by 1 proton

• A substance that is monobasic

• A substance that will dissociate easily

• A substance(S) that don't dissociate easily

Convert 0.37g/l to ppm (mg/l)

• 370 ppm

• 37 ppm

• 0.00037