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# Careers: Chemistry/Stoichiometry Problem

Question
2 CaSO4 + 6 CaS + 8 Hg ----> 8 HgS + 8 CaO

when 5.20 g of calcium sulfide is reacted with 2.21 g of calcium sulfate, what is the maximum amount of CaO produced? (assume excess Hg)

please please tell me how to get it. i've been working on this for the past 30 minutes :<

Normally I do not help with homework, but I would be happy to give you the method:

1.  find out which is the limiting reagent (LR) - convert both the calcium sulfide and the calcium sulfate to moles and look at the ratios.

2.  using the limiting reagent moles, calculate the number of moles of CaO made from that - so 4 moles of CaO for every one mole of CaSO4 if CaSO4 the LR, or 4 moles of CaO for every 3 moles of CaS if CaS is the LR.

3.  convert the moles of CaO into mass, and you should be done.

Best regards and good luck.

Careers: Chemistry

Volunteer

#### Dr. Jeffery Raymond

##### Expertise

Materials chemistry. Materials science. Spectroscopy. Polymer science. Physical Chemistry. General Physics. Technical writing. General Applied Mathematics. Nanomaterials. Optoelectronic Behavior. Science Policy.

##### Experience

Teaching: General Inorganic Chemistry I & II, Organic Chemistry I & II, Physical Chemistry I, Polymeric Materials, General Physics I, Calculus I & II
My prior experience includes the United States Army and three years as a development chemist in industry. Currently I am the Assistant Director of the Laboratory for Synthetic Biological Interactions. All told, 13 years of experience in research, development and science education.

Organizations
Texas A&M University, American Chemical Society, POLY-ACS, SPIE

Publications
Journal of the American Chemical Society, Nanoletters, Journal of Physical Chemistry C, Journal of Physical Chemistry Letters, Ultramicroscopy Proceedings of SPIE, Proceedings of MRS, Polymer News, Chemical and Engineering News, Nano Letters, Small, Chemistry.org, Angewandte

Education/Credentials
PhD Macromolecular Science and Engineering (Photophysics/Nanomaterials Concentration), MS Materials Science, BS Chemistry and Physics, Graduate Certificate in Science Policy, AAS Chemical Technology, AAS Engineering Technology