It's probably due to the assumption that every hydrated MgSO4 contains 7 water molecules...when actually it's likely some are 7 and some are 8.
If you like a bit of simple maths, you can work out what the average number of water molecules are given the experimental data...I've put the calculations in a spoiler if you wanna have a go before you look at the answer
Mr of the waters = (7x18) Mr of the whole hydrated compound = 24.3+32.1+64+(7x18)=246.4
(7x18)/246.4 = 0.511... x100 = 51.1%
Notice how this is different to the experimental value of 2.2/4.2 x 100 = 52.3%
This is not really technically more accurate. The question gives you experimental data for a reason, and if in the exam you decided to ignore that data and use the Mr you could easily lose marks
This is not really technically more accurate. The question gives you experimental data for a reason, and if in the exam you decided to ignore that data and use the Mr you could easily lose marks
I was referring to the Mr calculation being more accurate, since it assumes a pure sample. Obviously the experimental data would be the one to use in the exam.
I was referring to the Mr calculation being more accurate, since it assumes a pure sample. Obviously the experimental data would be the one to use in the exam.
I understand what you're saying its just an over complication especially if you didn't know how to do it in the first place
please can someone help me with his question: when 0.1 mol of atoms of an element reacts with chlorine there is an increase in mass of 7.1g. the element could be a.carbon b.sodium c.magnesium d.aluminium
please can someone help me with his question: when 0.1 mol of atoms of an element reacts with chlorine there is an increase in mass of 7.1g. the element could be a.carbon b.sodium c.magnesium d.aluminium
thanks any help would be appreciated!!
Find the number of moles of chlorine in the compound. Now you can deduce the ratio of the element to chlorine Which of those element will form a compound with chlorine in that ratio?
Find the number of moles of chlorine in the compound. Now you can deduce the ratio of the element to chlorine Which of those element will form a compound with chlorine in that ratio?
how can i find the number of chlorine molecules of the compound? i don't know the mass of it?
The element had an increase in mass by 7.1g when reacted with chlorine. The only source of the increase is chlorine that has reacted with the element. You know the relative atomic mass of Chlorine from the periodic table.