What role could energy have played in forming the black sand on the beach?

You are performing an experiment in a lab to attempt a new method of producing pure elements from compounds. the only problem is that you do not know what element will form. by your previous calculations you know that you will have 6.3 moles of product. when it is complete, you weigh it and determine you have 604.4 grams. what element have you produced?

Can someone me with questions 12 and 13 plz.

Under which circumstances are kp and kc equal for the reaction aa(g)+bb(g)⇌cc(g)+dd(g)?