(a)(i) Define a standard solution
(ii) Give the reason why a standard solution of sodium hydroxide cannot be made by weighing out accurately a given mass of the solid and making it up to the required volume of solution
(b) Give two ways by which a solid solute can be made to dissolve more quickly in a liquid Solvent
(i) Draw a labelled diagram of the apparatus used for drying solids in the laboratory
(c) State what would be observed if a fresh precipitate of silver chloride was;
(i) Exposed to light.
(ii) Shaken will excess aqueous ammonia
Explanation
(a) A standard solution is one whose concentration is known.
(i) Sodium hydroxide is deliquescent ie. absorbs water or CO\(_2\), from the atmosphere and this would add to the weight hence cannot be used as a primary standard. 2NaOH\(_{(s)}\) + 9H\(_2\)O + CO\(^2\) \(\to\) Na\(_2\)CO\(_3\) + 10H\(_2\)O.
(b)(i)
-By grinding to powder
-Heating dnd shaking
-Stirring vigorously.
(ii)
(c) It will turn from white to grey
(ii) The precipitate will dissolve to give a colour solution.