Assuming that the reaction is complete, all of the potassium sulfate is consumed. We relate the substances using the chemical reaction. We calculate as follows:
7.20 g K2SO4 ( 1 mol / 174.26 g) ( 1 mol O2 / 1 mol K2SO4 ) ( 32 g / 1 mol ) = 1.32 g O2 consumed in the reaction.
The correct answer is C. The weight downward and the friction moving forward creates thermal energy through kinetics and melts a tiny bit of the ice making it slick enough for the skate to slide.
