chemistry

posted by Raina

1.)Calculate the number of moles in
3.50 x 10^21 atoms of silver. Show all work.


2.) Calculate the number of atoms in 2.58 mol antimony. Show all work


3.) Determine the mass of 1.45 mol FePO4. Show all work.


4.) Calculate the number of mol in 6.75 g of NaCl. Show all work.


5.) What is the volume, in liters, of 2.54 mol methane (CH4) gas? Show all work.


6.) What is the empirical formula of a compound that is 36.2% aluminum and 63.8% sulfur. Show all work.


Thanks so much!!! :)

  1. Damon

    A mol is 6*10^23 of anything, sort of like a dozen is 12 of anything
    so
    3.50 x 10^21 atoms (1 mol of atoms/6*10^23 atoms)

    = (3.5/6) 10^(-2) = .58*10^-2 mol = 5.8 *10^-3 = .0058 moles

  2. Damon

    Now with that information and knowing that a mole of any chemical weighs its gram molecular mass I think you can do the rest
    for example a mol of water, H2O has mass
    2 H + O = 2(1) + 16 = 18 grams
    so for water
    18 grams is 6*10^23 molecules is one mole

  3. DrBob222

    4. mols = grams/molar mass

    5. At what pressure? If you mean standard pressure of 760 mm Hg then you need to remember that 1 mol of gas occupies 22.4 L at STP

    6. Take a 100 g sample which will be
    36.2g Al
    63.8g S.
    Convert these to mols by mols = g/atomic mass.

    36.2/27 = about 1.34
    63.8/32 = about 2

    Find the ratio. The easy way to do that is to divide both numbers by the smaller number. This makes the smaller number of the two exactly 1.0.
    Al = 1.24/1.24--This is to get qet 1.00
    S = 2/1.34 = 1.49
    Obviously, the answer is NOT Al1S1.5 because we want whole numbers. But a 1:1.5 ratio also is 2:3 in whole numbers so the empirical formula is Al2S3.

Respond to this Question

First Name

Your Answer

Similar Questions

  1. Chem

    Superscript 15 How many moles of Pb is 9.3 X 1015 atoms of pb?
  2. Science - Chemistry

    How many atoms are in 12g of Zinc? There are 6.02 x 10^23 atoms in 1 mol of anything. 1 mol of Zn has a mass of 65.38 g so 12 g is what part of a mol of Zn?
  3. science

    I need some help with my science homework. Well it is not really my homework it is my study guide but the actual test is the same as the study guide almost. They just switch around the words and stuff around to mess with your mind. …
  4. science

    I need some help with my science homework. Well it is not really my homework it is my study guide but the actual test is the same as the study guide almost. They just switch around the words and stuff around to mess with your mind. …
  5. chemistry

    calculate number of atoms in 4.67 mol of Ca(NO3)2 I got: 2.81 X 10^24 C atoms or should it be 28.11 x 10^23 C atoms?
  6. Chemistry

    I have realized I don't understand Avagado's number at all My book shows me this diagram instead of just providing a simple formulas that makes no sense at all here is what I have made sense of so far (6.022 x 10^23 atoms/mol)(mass …
  7. chem

    calculate the number of oxygen atoms in 0.25 mol fluoroacetic acid (C2H3O2F) show work if possible
  8. chemistry

    Calculate the following quantities. (See the periodic table.) (a) mass, in grams, of 2.54 10-2 mol of CdS g (b) number of moles of NH4Cl in 90.0 g of this substance mol (c) number of molecules in 5.081 10-2 mol C6H6 molecules (d) number …
  9. Chemistry Help

    1.) Calculate the number of atoms in 2.58 mol antimony. 2.) Determine the mass of 1.45 mol FePO4. 3.) Calculate the number of mol in 6.75 g of NaCl. 4.) What is the volume, in liters, of 2.54 mol methane (CH4) gas?
  10. Chemistry

    Calculate the number of atoms in 2.58 mol antimony. Its an example problem, I need help!

More Similar Questions