In the following question, two statements and five

Solution

(a) The sentences are contrasting in nature since they present two contradictory ideas. 1-tells us that a mixture gives a precipitate of sulphur, while 2-tells us that another solution does not yield sulphur. WHEREAS is used to join parts of a sentence which talks about two contrasting subjects in a similar situation. "The mixture of potash alum and charcoal lead to the precipitation containing sulphur whereas the solution of blue vitriol on heating merely becomes turbid and does not yield sulphur in the precipitate." Thus, (a) is the right answer. WHENEVER, which means at any given time, can be used to join parts of a sentence where some event is occurring because another is occurring at the same time. WHEREBY, meaning by which, can be used to join sentences where an event occurs by virtue of some system or person SINCE and AS are used when joining parts of a sentence that share a cause and effect relationship