Four students A,B,C and D were asked by their teacher to arrange the set up I to IV as given below and identify the gas, if any evolved in each case:

After observations the students arrived at the inferences recorded in the following table:

The correct observations and inferences have been reported by the student:

Aluminium sulphate and copper sulphate solutions were taken in two test tubes I and II respectively. Iron filings were then addd to both the solutions. The four students A,B, C and D recorded their observations in the form of a table as given on the next page. The correct set of observations have been recorded by the student:

Aqeuous solutions of zinc sulphae and iron sulphate were taken in test tubes I and II by four students A,B, C and D. Metal pieces of iron and zinc were dropped in the two solutions and observations made after several hours and recorded in the form of a table as given below: The correct reporting has been made in observation reported by the student:

Four set ups a given below were arranged to identify the gas evolved when dilute hydrochloric acid was added to zinc granules. The most apropriate set up is:

Four students added a small amount of ethanoic acid to sodium hydrogencarbonate. The gas evolved was tested for its behaviour with burning splinter and lime water. They reported their observations as given on the next page. The correct observations have been reported by student: