1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: - Mole and Avogadro's Number -

  1. Nov 19, 2005 #1
    2.95 mol Ba(OH)4 to atoms. (I think I wrote this problem wrong. It might be (OH)2 instead).
    I'm confused >.< Do I:
    1) multiply 2.95 mol by 6.02 x 10^23 atoms or
    or
    2) multiply 2.95 mol x 6.02 x 10^23 molcules x 9 atoms.
    or is it something else?

    Also, how do I do these?
    Calculate the mass of 3.01 x 10^23 formula units (ions) of Strontium hydroxide.
    Find the number of atoms in 16.0g of sulfur

    Please help if you can. ~____~
     
    Last edited: Nov 19, 2005
  2. jcsd
  3. Nov 19, 2005 #2

    eax

    User Avatar

    moles is amount of particals. When this compound is broken down it is split into 1Ba and 4(OH) [according to you].

    moles * 6.02E23= number of particals
    (Number of particles)*(Number of particles the molecule can decompose to)=number of ions of that particular particle.
     
  4. Nov 20, 2005 #3
    hence no. of molecules=2.95*6.023*10^23
    hence no. of atoms= no. of molecules*no. of atoms per molecule(9 in your case, though it is Ba (OH)2, i.e. 5):smile:
    Strontium hydroxide is Sr (OH)2
    hence no. of formula units= no. of atoms
    hence mass = (molarmass/avogadro's no.)*no. of units
    same for next.
    refer University Chemistry by Bruce Mahan for details.
     
  5. Nov 20, 2005 #4

    GCT

    User Avatar
    Science Advisor
    Homework Helper

    if they're asking for the atoms of Ba(OH)2 and not its constituent ions, then you would simply solve this by factor labeling

    2.95mol Ba(OH)2(6.022x10^23 molecules Ba(OH)2/1mol Ba(OH)2) =?, you should verify that the units cancel out during such processes
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook




Loading...
Similar Threads for Mole Avogadro's Number Date
How to find moles of O in CO molecule? Apr 12, 2018
Moles question Feb 11, 2018
Thermodynamics mole ratio question Jan 27, 2018
AvLaw - Which is the correct method of finding moles of gases? Dec 17, 2017
Estimating Avogadro's Number Jan 18, 2015