While titrating dilute HCl solution with aqueous NaOH, which of the following will not be required?

Solution

Chemistry ma’am · 3 steps

Picture the bench for an acid-base titration: nothing gets heated, and every volume is measured precisely.

1. What the titration needs. A known volume of HCl goes into the flask, and NaOH is added from above until an indicator changes colour. The reaction HCl + NaOH → NaCl + H₂O is fast at room temperature.

   Item	Job in this titration	Needed?
   Pipette, distilled water	Pipette delivers an exact volume of HCl; water rinses the glassware	Yes
   Clamp, phenolphthalein	Clamp holds the burette upright; phenolphthalein shows the end point (colourless to pink)	Yes
   Burette, porcelain tile	Burette adds NaOH drop by drop; the white tile makes the faint pink easy to see	Yes
   Bunsen burner, measuring cylinder	No heating is needed, and a measuring cylinder is too rough for titration volumes	No

2. Why not heat. Heating is used only for slow reactions, such as KMnO₄ with oxalic acid at about 60 °C. Neutralisation of a strong acid by a strong base needs no burner.
3. So. The pair that is not required is the Bunsen burner and measuring cylinder, option (d).

The idea to keep. In a titration, volumes are read from a pipette and burette, never a measuring cylinder. A burner appears only when the reaction is slow, as in the KMnO₄ and oxalic acid titration.

Answer from the NTA final answer key. Solution by PrepWiser.