Show a correct numerical setup for calculating the density of NH3(g) at STP?

Consider the following reaction at equilibrium. 2co2 (g) 2co (g) + o2 (g) h° = -514 kj le châtelier's principle predicts that the equilibrium partial pressure of co (g) can be maximized by carrying out the reaction a. at high temperature and high pressure b. at high temperature and low pressure c. at low temperature and low pressure d. at low temperature and high pressure e. in the presence of solid carbon

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

Stoichiometry- i need with 14 and 15! an explanation would be appreciated!