The balanced equation below represents the reaction between carbon and hydrogen to produce ethane.
2C(s) + 3H2(g) → C2H6(g) + energy
Determine the number of moles of O2(g) needed to completely react with 8.0 moles of CO(g).

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Different isotopes indicate that an element will have different numbers of

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

Light waves travel than sound waves.