1What type of reaction is used in a titration to find the concentration of hydrochloric acid?
Neutralisation reaction
2Which base is used in the titration experiment to determine the concentration of HCl?
Sodium hydroxide
3What indicator is used in this titration?
Methyl orange
4What is the colour change of methyl orange in the titration?
Yellow to red
5Why is methyl orange used as the indicator in this titration?
It changes colour sharply at the pH of the equivalence point for a strong acid-strong base titration
6What apparatus is used to measure a fixed volume of sodium hydroxide?
Pipette
7Why is a pipette filler used when handling the pipette?
To avoid direct mouth contact and ensure safety
8What apparatus is used to deliver hydrochloric acid during the titration?
Burette
9Why is the conical flask used in a titration?
It allows easy swirling without spillage
10What should you do before starting the titration with the burette?
Rinse the burette with hydrochloric acid
11Why do you rinse the conical flask with distilled water and not hydrochloric acid or sodium hydroxide?
To avoid altering the concentration of the reactants
12What is the purpose of a rough titration?
To get an approximate value for the end point
13How do you improve accuracy in a titration?
Repeat until two concordant results are obtained
14What does "concordant results" mean in titration?
Two results within 0.1 cm³ of each other
15Why is a white tile placed under the conical flask?
To help observe the colour change clearly
16Why must the burette reading be taken at eye level?
To avoid parallax error
17What is the titre in a titration?
The volume of acid required to neutralise the alkali
18Why do you add hydrochloric acid from the burette slowly near the end point?
To avoid overshooting the end point
19What safety precaution is important when handling hydrochloric acid?
Wear eye protection and gloves
20What do you do with anomalous results in titration?
Exclude them from the mean titre calculation
21what is the method to find the concentration of a solution of hydrochloric acid (include steps)
1-Wash out a 250 cm³ volumetric flask with distilled water
2-Use the pipette to add 25 cm³ hydrochloric acid in to the volumetric flask and make the rest up with distilled water
3-Pour a 25 cm³ sample of the HCl solution in to the conical flask and add a few drops of phenolphthalein indicator
4-Prepare your apparatus for the titration – sodium hydroxide in the burette and the hydrochloric acid in the conical flask
5-Titrate the contents of the flask against the NaOH solution and record the titre to the nearest 0.05 cm³ (when a permanent pink colour appears)
6-Conduct additional titrations until you have concordant values