November 25, 2024, 04:25:18 PM
Forum Rules: Read This Before Posting


« previous next »
Pages: [1]   Go Down

Topic: old fart trying to understand chemistry :-)  (Read 3536 times)

0 Members and 1 Guest are viewing this topic.

Offline Craig65

  • New Member
  • **
  • Posts: 3
  • Mole Snacks: +0/-0
old fart trying to understand chemistry :-)
« on: March 17, 2019, 12:03:10 PM »
How would I work this out? I want to know how to do the calc not just get an answer.. with thanks Craig

If the Heat of Combustion of Benzene (C6H6) is 4.25MJ per mole; How  much heat can I expect to be released if I burn 100g of Benzene knowing that the Combustion Efficiency is only 80%.
Logged

Offline Mitch

  • General Chemist
  • Administrator
  • Sr. Member
  • *
  • Posts: 5298
  • Mole Snacks: +376/-3
  • Gender: Male
  • "I bring you peace." -Mr. Burns
    • Chemistry Blog
Re: old fart trying to understand chemistry :-)
« Reply #1 on: March 17, 2019, 12:22:29 PM »
The first step will be converting grams of benzene to the units of moles of benzene. Can you do that? Hint, you'll need to know benzene's molar mass to figure it out.
Logged
Most Common Suggestions I Make on the Forums.
1. Start by writing a balanced chemical equation.
2. Don't confuse thermodynamic stability with chemical reactivity.
3. Forum Supports LaTex

Offline Craig65

  • New Member
  • **
  • Posts: 3
  • Mole Snacks: +0/-0
Re: old fart trying to understand chemistry :-)
« Reply #2 on: March 18, 2019, 05:51:19 AM »
1 mole of Benzene = 0.012802156497658 *100g = 1.2802156497658 mol
Logged

Offline Craig65

  • New Member
  • **
  • Posts: 3
  • Mole Snacks: +0/-0
Re: old fart trying to understand chemistry :-)
« Reply #3 on: March 18, 2019, 05:55:47 AM »
therefore 100grams of Benzene = 1.2802156497658 * 4.25mj * .8 = 4.35273320920372 mj ?
Thanks
Logged

Offline AWK

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7976
  • Mole Snacks: +555/-93
  • Gender: Male
Re: old fart trying to understand chemistry :-)
« Reply #4 on: March 18, 2019, 06:56:46 AM »
4.25, 100, 80
4.35273320920372
How many significant digits you should use in the final result (remember about rounding rules)?
Logged
AWK
Pages: [1]   Go Up
« previous next »
Sponsored Links