The total pressure of an 02-Ar-He gas mixture is 755 mmHg. If the partial pressure of Ar is 174 mmHg and the partial pressure of He is 389 mmHg,
then the partial pressure of 02 is what?

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.)

Answer asap need it by wednesday morning calculate the ph of 0.02m hcl best answer will be brainliest

What happens to the temperature of a substance when the average kinetic energy of its particles increases?