Chemistry lvl1 question
Peter's year 11 class is given the task of devising a method to find out when an acid has been neutralised by a base. Their experiment involves adding sodium hydroxide solution to hydrochloric acid solution.
Discuss how the students could tell when the hydrochloric acid has been neutralised and what effect adding the sodium hydroxide has on the pH of the solution.
In your answer you need to include the following information :
-An explanation of what neutralisation is in terms of acid-base reaction.
-What indicator would be sensible.
-What the studentys would observe as the sodium hydroxide is added to the acid.
-A word equation and a balanced symbol equation for the reaction.
Please help~!
thx
Peter's year 11 class is given the task of devising a method to find out when an acid has been neutralised by a base. Their experiment involves adding sodium hydroxide solution to hydrochloric acid solution.
Discuss how the students could tell when the hydrochloric acid has been neutralised and what effect adding the sodium hydroxide has on the pH of the solution.
In your answer you need to include the following information :
-An explanation of what neutralisation is in terms of acid-base reaction.
-What indicator would be sensible.
-What the studentys would observe as the sodium hydroxide is added to the acid.
-A word equation and a balanced symbol equation for the reaction.
Please help~!
thx
-
Well first, a neutralisation reaction is a reaction where by an acid is reacted with a base or alkaline to form salt and water. When the total proton H+ from the acid is consumed by the OH- from the base or alkaline, then neutralisation has taken place.
In your own case, it is a reaction between HCl and NaOH, so the best indicator will be methylorange, and this indicator is dropped into the NaOH solution. When the acid comes in contact with the NaOH, the neutralisation process begins and the colour changes completely from its initial yellow colour. At this point, all the hydrogen ions have been consumed and is thus called the endpoint of the reaction. The indicator only shows that the total +ve ions on the acid has been neutralised.
Equation of reaction:
HCl(acid) + NaOH(alkaline) = NaCl(salt) + H2O(water). It should be understood that what the alkaline NaOH does is to increase the pH of the acid solution to a become a neutral solution closer to pH 7.
In your own case, it is a reaction between HCl and NaOH, so the best indicator will be methylorange, and this indicator is dropped into the NaOH solution. When the acid comes in contact with the NaOH, the neutralisation process begins and the colour changes completely from its initial yellow colour. At this point, all the hydrogen ions have been consumed and is thus called the endpoint of the reaction. The indicator only shows that the total +ve ions on the acid has been neutralised.
Equation of reaction:
HCl(acid) + NaOH(alkaline) = NaCl(salt) + H2O(water). It should be understood that what the alkaline NaOH does is to increase the pH of the acid solution to a become a neutral solution closer to pH 7.