help me guys

[captainhyderabad]

iron was added to H2SO4 AND IT WAS GENTLY WARMED..WHY THE MIXTURE WAS GENTLY WARMED?
q.2 IRON DISSAPEARED AND A PALE GREEN SOLUTION WAS FORMED TELL ME WHY THE REACTION STOPPED?
q.3 dISCUSS THE ADVANTAGES AND DISADVANTAGES OF MEASURING THE PH OF LEMON JUICE BY USING LITMUS PAPER OR BY USING PH INDICATOR SOLUTION OR BY PH METER
q.4 WHY DOES THE COLOR OF THE TEA CHANGE WHEN LEMON IS PUT IN THE TEA?
q.5 HOW WOULD YOU SHOW THAT A SAMPLE OF ORANGE JUICE CONTAINS TWO YELLOW DYES

 

[abcde]

AoA!
1. The mixture was gently warmed to speed up the chemical reaction b/w iron and sulphuric acid as iron is a moderately reactive metal.
2. All the iron had been used up.
5. Carry out paper chromatography. (The amount of detail you give here depends on the mark allocation).

 

[captainhyderabad]

what about Q.3 and Q.5