1) you are asked to make 10 miles of iron (fe) from iron oxide (fe2o3) and excess carbon monoxide (co). fe2o3(s) + 3co(g)—> 2fe(l) + 3o2(g). how many moles of iron oxide must you use.

a) 3 moles
b) 2 moles
c) 10 moles
d) 5 moles

2) 2c4h10 + 13o2–> 8co2 + 10h2o. if i want to produce 50g of h2o using the above combustion reaction, how many mol of c4h10 should i use?

a) 0.55 mol c4h10
b) 10 mol c4h10
c) 2.77 mol c4h10
d) 3.79 mol c4h10

Look at the spectrums of a star moving towards earth and a motionless star. which of these is a correct inference that can be draw from the observation of the two spectrums? (2 points) the spectrum of a motionless star is difficult to be viewed separately using oridinary telescopes. the spectrum of a motionless star is identical to the spectrum of a star which moves towards earth. the spectrum of a star shifts towards the red region when the star moves towards earth. the spectrum of a star shifts towards the blue region when the star moves towards earth.