Explaination on vitamin B1

How do you find a theoretical mass? is there a difference between theoretical mass and theoretical yield?

If you have 5.25 grams of methane (ch4), how many grams of co2 will you produce ?

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line