On "q=mc(deltaT)" questions the unit for temperature in the mark-scheme is degrees Celsius. Surely if the units for specific heat capacity is JK^-1g^-1, then temperature should be measured in Kelvin?
No it's not "wrong" because it would get you the marks in an AS exam. Hey, look at the title of this thread, it says AS!! Not Advanced Highers!
sorry yeah I was thinking this was an A level thread for some reason. I still don't think simplifying it by making it wrong is helping anyone. It's not even any simpler really
On "q=mc(deltaT)" questions the unit for temperature in the mark-scheme is degrees Celsius. Surely if the units for specific heat capacity is JK^-1g^-1, then temperature should be measured in Kelvin?
if you think about it the difference between the temperatures in Kelvin is exactly the same as the difference in temperature in celsius, theoretically you are meant to work in Kelvin but this missed out step would not alter your answer
Hi can someone please explain these two questions for me? Thanks
1) How many unpaired electrons does a does a Nitrogen atom in its ground state have?
2) When 0.1mol of atoms of an element reacts with chlorine there is an increase in mass of 7.1g. A student is told the element could be Carbon, Sodium, Magnesium or Aluminium. What is the element?
Especially the second one I'm not sure about! Thanks
Hi can someone please explain these two questions for me? Thanks
1) How many unpaired electrons does a does a Nitrogen atom in its ground state have?
2) When 0.1mol of atoms of an element reacts with chlorine there is an increase in mass of 7.1g. A student is told the element could be Carbon, Sodium, Magnesium or Aluminium. What is the element?
Especially the second one I'm not sure about! Thanks
N has electronic configuration of 1s2 2s2 2p3 and in p orbital the three electrons are unpaired
Where can the increase in mass come from? Only chlorine. So calculate the number of moles of chlorine atoms (well they are ions but molar mass is the same anyway) in that compound See the ratio of 0.1mol and the amount of chlorine and you will see
N has electronic configuration of 1s2 2s2 2p3 and in p orbital the three electrons are unpaired
Where can the increase in mass come from? Only chlorine. So calculate the number of moles of chlorine atoms (well they are ions but molar mass is the same anyway) in that compound See the ratio of 0.1mol and the amount of chlorine and you will see
Ah lovely!! How did you know the mass increase is solely down to the chlorine. That is what didn't occur to me when doing the question...
its saying the INCREASE in mass, not what the final mass of the atoms and chlorine is combined. The INCREASE in mass after the two have REACTED is due to the ADDITION of Cl because that's the only thing that can cause the increase in mass because the ATOMS stay the SAME. so you do 7.1/35.5 = 0.2 moles of cl. ratio of atoms to Cl is: 1:2, so atom has to be +2!
I was also stuck on this Q, but I literally only JUST got it by reading your post!!
Thing i don't understand, is why you divide 7.1g by 35.5 and not by 71 since Cl2 is diatomic O.o maybe Cobalt can explain