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What is the frequency of a photon of light with a wavelength of 615 nm?  Answer in the correct number of significant figures.  You must show all your work and submit an image of your work to receive credit. Work must be in your own writing. 

Based on the balanced equation, how many moles of H2O can form from the reaction of 6 moles of CH4? CH4 (g) + 2 O2 (g)  –> CO2 (g)  + 2 H2O (g)

A chemist carries out this reaction in the laboratory, using 4.31 grams of zinc and an excess of sulfur: Zn + S –> ZnS From the balanced equation, she calculates that she should obtain 6.41 grams of zinc sulfide.  However, she isolates only 5.01 g of product.  What is her percent yield for this reaction?

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Water has the formula H2O.  Water can be made from the reaction of hydrogen and oxygen.  If [x] g of hydrogen react fully with [y] g of oxygen, then ____ of water is made.

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In the SI system of measurement, the unit of mass is the 

What is your favorite subject? Hint: This is a HISTORY class.

Students’ comments from the Fall 2023 course evaluation on grading in the course: 

Rust has the formula Fe2O3 and it’s made from iron metal reacting with oxygen over time.  Assume you had a [x] g block of pure iron metal than fully oxidized to rust and the mass of that product was [y] g.  What must have been the mass of oxygen that initially reaction with pure iron?