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CHEM AND BIO HELP AND TIPS HERE

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nid404:
to ur 1st question

The heat given out would be distributed in a larger volume of acid....so temp rise will be less...
H=mcdt  (h=heat given out/absorbed, c=sp heat capacity, dt=change in temp)
H will be the same
m will increase.....c is constant....so dt will decrease

ya?

nid404:

--- Quote from: Ari Ben Canaan on April 09, 2010, 04:37:57 pm ---
Another example.

 
If 50 cm3 of HCl 1 mol/dm3 conc. are added to 1 g of CaCO3. We get a max. CO2 volume of 60 cm3

 If 50 cm3 of HCl 0.5 mol/dm3 conc. are added to 1 g of CaCO3. We get a max CO2 volume of 30 cm3 BUT WHY ???



--- End quote ---

ok let's write down the equation

CaCO3 + 2HCl---> CaCl2 + H2O+ CO2
look at the ratio
HCl : CO2
2 :1

no of moles of HCl in case 1= 0.05---> 0.025 moles of CO2=60cm3
no of moles of HCl in case 2= 0.025--->0.0125 moles of CO2= 30cm3

got it?

holtadit:
Got it Nid.

Thanks for taking the time out to help me... again XD


+rep

nid404:
no prob...
I like it :)

holtadit:

--- Quote from: nid404 on April 09, 2010, 05:47:54 pm ---no prob...
I like it :)

--- End quote ---

Chemistry rocks....

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