Kimms (jamour_ma_vie) wrote in _homeworkhelp_,
Kimms
jamour_ma_vie
_homeworkhelp_

Please please please help

I am in so much trouble and I've never come down to this but I am BEGGING someone to help me with these two problems that I have for my chemistry homework.

A student mixes 0.400 L of 0.5M HCl with 0.250 L of 1.00 M NaOH. What would the Molar concentration of NaCl of the new solution be? What would the pH of the new solution be? If the solution were diluted 10-fold (to 5.75 L) what would the pH be?                
             
         I did this: 
           

Moles HCl = (Moles of HCl/Liter of HCl solution) X Volume HCl solution

      (0.5moles of HCl/1 liter of HCl) X 0.400 L HCl solution

      1.25 moles of HCl
But I have no idea if I'm evenon the right track....


The other problem that I have is:
 

Calculate the energy released (using bond energies) from 155 g of hexenoic acid

 

C-C     345 kJ/mol

C=C    615 kJ/mol

C-H     415 kJ/mol

C-O     360 kJ/mol

C=O    805 kJ/mol   (For carbon dioxide)

C=O    750 kJ/mol   (For everything else)

O-H     460 kJ/mol

O=O    494 kJ/mol


I found that 155g of Hexenoic Acid is equal to 2.418 moles, but I don't know where to go from here? Do I just put kJ/2.418 and then divide?
Tags: chemistry
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