OCR Gateway Chemistry C4C5C6 - 13/06/13

when you increase the temprature, equilibrium tries to oppose it, thus favours the side of the reaction which is endothermic, to reduce the amount of heat,to rreduce the temprature

when you decrease the temprature, equilibrium tries to oppose it, thus favours the side of the reaction which is exothermic,to produce more heat and even it out

With presure you need to look at the number of moles, of each Gas on both sides of the equation

If you increase the pressure, you increase the rate of the side of the equation that has more moles of gas .... so equilibrium shifts to the other side,where there are less moles,and also more of that reactant/product


Since it is a reversible reaction.... it can go both ways - so you want more product and so you change the conditions (temprature,pressure,concentration) to make more product!

In weak acids why does the equilibrium lie to the left?? Not sure if I've got this confused.

Woo Geography over! Time to spend my whole day on Chemistry.

How was it ?

BEcause there are less H+ protons produced

so the higher concentration is on the left, so equilibrium also lies on the left

Ryan

You should know them, just look at the periodic table and check which group.

For instance because Br is in group 7 it has a charge of -?

Therefore:
H+
Li+
Be2+
B3+
C4-
N3-
O2-
F-
N.....?

How do you work out the percentage by mass?

Surprisingly good, even though I didn't revise that much for it.

I'm so looking forward to it, I hope I get an A* in it especially since i got 139 in c1c2c3 and 45/48 in coursework.

C wouldn't lose electrons, too much energy. That's why it bonds covalently.

It'll be group 1,2,6,7 but yeah, that's the gist.

N is group ? So it is N ??

what?

How would you calculate the percentage by mass of nitrogen in ammonium sulfate (NH4)2 SO4

nice

are you starting with C4 first...or diving into the deep-end with C6 ? :P

ryan

Oh ,, that makes a bit more sense

you need to work out the mass of nitrogen ,,,then of ammonium sulfate..or its given

then : (nitrogen/ammonium sufate) x 100 = your % ....

i think that is it..

Ryan

N is group 0 so i guess it doesn't have a charge because it...bonds covalently...?