How many moles of oxygen gas are produced from the decomposition of six moles of potassium

From the equation, 32 equiv dixoygen gas evolve from 1 equiv chlorate.

You started with 6 equiv chlorate, and thus 9 equiv dioxygen gas are evolved. This is a common undergrad experiment. I think you need to add some sort of manganese oxide catalyst.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.