Why is haemoglobin a pure substance

How many moles of al3+ ions are in 1.25 moles of al2o3

3. how much energy in joules is required to evaporate .0005 kg of liquid ammonia to vapor at the same temperature? 4. how much energy ( in megajoules ) is given up by .75 kg of water at 0c when it freezes to form ice at 0c? 5. explain how heat works between and at critical temperatures?

Which characteristics can be used to differentiate star systems? check all that apply.