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ty for the help..i had that in mind but the whole density and heat capacity through me off

the heat of neutralisation of sodium hydroxide acid is measured in a calorimeter. 5.75kJ of energy is released when 100mL of 1.0molL-1 HCl and 100ml of 1.0molL-1 NaOH are mixed. (density of solution 1 g mL-1 ; specific heat capacity of solution if 4.18) calculate the heat of neutralisation per...

was in mai test the other day, a sim question...couldnt do it then but now its a synch :(

50mL 0.20mol/L lead Nitrate solution is added to excess potassium iodide contained in 30mL of solution. Both solutions are initiallly at 19.6 degrees. After mixing, the temperature rose to 22.2 degrees. Calculate the enthalpy change (per mole of Pb2+) for the reaction? Answer is : -87kJ/mol...

yeah i understand now. Just dont know how to do one last question. 50mL 0.20mol/L lead Nitrate solution is added to excess potassium iodide contained in 30mL of solution. Both solutions are initiallly at 19.6 degrees. After mixing, the temperature rose to 22.2 degrees. Calculate the enthalpy...

why do you multiply the delta H of .52 by 0.05 instead of dividing it? Im confused on that part.

I got these questions and im totally stuck. Help would be much appreciated! Calculate the amount of heat released or absorbed when: a) 5g sulfur dixoide reacts with excess oxygen (delta H = -198 kJ/mol) b) 25 mL 0.20 mol/L HCl is added to 50mL if a solution containing excess ammonia (delta H...

we just had our speeches recently and the one liner i remember was this one guy who went, "the principal told us to not make a speech about how cool we are so i had to rewrite my speech!" we all cracked up :D good luck!

Use the fact that the derivative of root x is 1 over (2rootx) differentiate root (7x) answer says root 7 over 2 root x and I am wondering how to get there...i can get upto 1 over 2 root 7x

Anyone got any notes on portrait of a lady (the film) in regard to the values and attitudes present at the time and also the context in which these are portrayed in victorian society and that of today? I have an essay to write about this and two Browning poems which i got covered. Stuff like...

1)how many moles of sodium are there in a 175g packet of table salt, NaCl? 2)one litre of chlorine gas weighs 3.214g when measured at STP. use this info to calculate the atomic mass of the element chlorine. is this result the same as is quoted on the periodic table? suggest a reason for any...

thanks!

There are ten points in a plane, five of which are collinear. No other set of three of these points is collinear. How many triangles can be formed using the ten points as vertices.

was it a math exam? howd you go?

yeah i see all that now..s many mediocre mistakes in this...and its not even remotely challenging or hard to get my head around..maybe i dont feel like doing this or something anyways guys thanks heaps for the help..clarified a few things for me which i didnt actually realise and yeah =]

i got the LHS alright but with the rhs do you sub in 2t/1-t^2 for tan1/2@? edit: nevermind i am realy acting stupid today not seeing simple things like that tan1/2@ becomes t omgg...this is like the only trig i dont like LOLL..its in my way of a perfect score grrr!

i got proving ones coming up but like how hard could they be? this is my very last question i gotta do. just steps to guide me through it will be enough i think?

oh that makes a lot of sense now! does that mean for like 4f) it resembles tan and 3b,d) sine again?

what im still not getting is why did you choose to sub the angle in sin @...why not cos? how did that come about?