June 21, 2024, 10:13:35 PM
Forum Rules: Read This Before Posting


Topic: Enthalpy of reaction  (Read 1657 times)

0 Members and 1 Guest are viewing this topic.

Offline purplemonkey123

  • Regular Member
  • ***
  • Posts: 13
  • Mole Snacks: +0/-0
Enthalpy of reaction
« on: December 06, 2015, 11:55:22 AM »
Hellooo!

I'm doing an lab with my online class (http://ksykang.tripod.com/chem/CHEM_HES.HTM)
I'm having trouble calculating the enthalpy of the neutralizaiton of solid sodium hydroxide

NaOH(s) + HCl(aq) H2O(l) + NaCl(aq)
my data
volume of hcl = 25ml of 2M
mass of naoh = 2g of 2M
temperature change: 30C
heat capacity = 4.184

I calculated qcal = 4326.67J
which would be qrxn = -4326.67J

I know i have to find dH by dividing q by moles but do i divide it by the moles of HCl or NaOH?

I'm assuming it'd be NaOH because for the other reaction in my lab (NaOH(s) --> NaOH (aq))
I found q then divided it by the moles of NaOH instead of water
... but im not even sure if that part is right...


« Last Edit: December 06, 2015, 12:10:46 PM by purplemonkey123 »

Offline Vidya

  • Full Member
  • ****
  • Posts: 839
  • Mole Snacks: +46/-62
  • Gender: Female
  • Online Chemistry and Organic Chemistry tutor
    • Online Chemistry Tutor
Re: Enthalpy of reaction
« Reply #1 on: December 07, 2015, 06:26:18 AM »
Check the limiting reactant ...divide it by moles of the limiting reactant or mole of water formed

Sponsored Links