I don't do ocr but from what I've read for first question it's just the Mr of copper(2) divided by the Mr of the whole compound times by 100....so the Mr of copper is (63.5*2) divided by the Mr of the whole compound (63.5*2)+32 and times by 100 this gets you 79.9%..rounded. Is this correct?
It's copper with a little 2 so it wouldn't be the Ar, it would be the Mr?
i guess fro part aii you just multitply the percentage by 1kg, to give 0.798kg of cu ?
Well I got the question right....and Ar , mr is also right