Small quantities of hydrogen and helium gas at the same temperature are released simultaneously at one end of a laboratory. State with reason which gas is more likely to be detected at the other end.

Which of these describes the rate of this chemical reaction? h2 + cl2 → 2 hcl a. an increase in the concentration of hcl and h2 with time b. an increase in the concentration of hcl with time c. an increase in h2 and cl2 with time d. a decrease in hcl and cl2 with time