In a (i) Look for the peak with the highest value for m/z, and that value is the relative formula mass of the compound. a(ii) we add O and H molar mass (16+1) and then deduct it from 88 =71 so the CH3 group at one end has Mr 15. Deduct it from 71=56,now divide 56 by 14 (as -CH2 has Mr 14) and you get 4. So the x=5 (4+1 in methyl group at the terminal end) and y=11 as (4*2+3 in the methyl group) b. In three as it doesn't oxidise so its a tertiary alcohol with formula CH3-CH2-CH2-CH2-CH2-OH. Hope you understood. Better see the markscheme!
Good evening i am having some serious bother with this question-describe the significance of enthalpy during iron production in the blast furnace whilst explaining how heat exchange can be put to good use. Any help would be great, thank you
I've got methyl orange and phenolpthalein, but I can't figure out how you work out the number of moles of each substance.
I understand that the first end point = half of na2co3 and naoh Second end-point = 2nd half of na2co3, but where does CO2 come into it?
Eqn: 2NaOH + CO2 --> Na2CO3 + H2O
To work out the concentration of the analyte you need to work out the concentration of what you're titrating it against, so use the concentration of your standard solutions to do it.
The moles would be with this equation: No. moles = (concentration x volume (cm3))/1000 or N = C x V (dm3).
To work out the concentration of the analyte you need to work out the concentration of what you're titrating it against, so use the concentration of your standard solutions to do it.
The moles would be with this equation: No. moles = (concentration x volume (cm3))/1000 or N = C x V (dm3).
It's being titrated with HCL and i've got the volumes for both end-points. i know that the second end-point minus the first-end point gives you the volume needed to react with half of the na2co3. Times it by two to give the volume needed for all the Na2CO3. Right?
What i dont understand is the HCl titre --> how do i calculate the number of moles of HCL and would i use the following equation to calculate the moles of CO2?
Question is one of simple maths really. The formula mass of the alcohol is 88. So subtract the mass of the OH functional group from the formula mass of the alcohol. This leaves you with 71. This must be the formula mass of the alkyl group represented by carbon and hydrogen in their relative quantities. Now it is simply a question of finding how many carbon atoms will make up as much of the 71 as possible. As carbon has a relative atomic mass of 12, this means there are 5(12×5=60). This means the remaining 11 must be all hydrogens. Hence the alkyl group must have the formula C5H11
1. First I calculated both the moles of HCl and NaOH.. moles of NaOH: 2.54 X 10-3 moles of HCl: 5 X 10-3
because we titrated the acid with the alkali we can take the number of mole of HCl from NaOH. so (5X10-3)- (2.54X10-3)= to get us 2.46 X 10-3 moles used.
Because it is a 2:1 ratio we divide the number of moles by 2 to get us 1.23 X10-3 in 25cm3. We can then multiply the number of moles by 10 (to get it in 250cm3): 0.0123
Now we can calculate the mass: Mass= moles x Mr: 0.0123 x 132.1= 1.62483g
1. First I calculated both the moles of HCl and NaOH.. moles of NaOH: 2.54 X 10-3 moles of HCl: 5 X 10-3
because we titrated the acid with the alkali we can take the number of mole of HCl from NaOH. so (5X10-3)- (2.54X10-3)= to get us 2.46 X 10-3 moles used.
Because it is a 2:1 ratio we divide the number of moles by 2 to get us 1.23 X10-3 in 25cm3. We can then multiply the number of moles by 10 (to get it in 250cm3): 0.0123
Now we can calculate the mass: Mass= moles x Mr: 0.0123 x 132.1= 1.62483g
% by mass: 1.62483/3 multipied by 100: 54.12%
Heey
I have solved it exactly as you said and I keep getting 54.16% which is really annoying and then on my calculator, I have put your numbers and it keeps giving me 54.16 so how you're getting 54.12% ?
I have solved it exactly as you said and I keep getting 54.16% which is really annoying and then on my calculator, I have put your numbers and it keeps giving me 54.16 so how you're getting 54.12% ?
Lool thank you so much!! I've been stuck on it for ages!
Hey so sorry for late reply it was bugging me for ages!😂 Hope this is right: I calculated original moles of ammonium sulphate which is 0.0227 and the moles we have already calculated which was 1.23x10-2 so then I divided 1.23x10-2 by original moles 0.0227 to get me 54.12%
Hey so sorry for late reply it was bugging me for ages!😂 Hope this is right: I calculated original moles of ammonium sulphate which is 0.0227 and the moles we have already calculated which was 1.23x10-2 so then I divided 1.23x10-2 by original moles 0.0227 to get me 54.12%
Thank you so much for your effort and I guess that's right!!