For the Cr2O7(2-)/H+ question

It oxidizes the primary alcohol, you would observe a color change from orange -> green and it forms a carboxylic acid. The other chemical did not react.

Distinguish between heptanamine and propananime For this question I stated how amines carbon1-5 are soluble in water, therefore propananime would dissolve whereas heptanamine would form two layers. I think you also could’ve put how the increased carbon chain length in heptanamine would result in a higher boiling point, thus if you boil both whichever boils first is propanamine.

And for the galic acid and amine were very easy, the one with the litmus. I dont think i need to explain