Can anyone help PLEASE, its for a test!

Harvey mixes two liquids. which observation of the new mixture most likely indicates a precipitate is forming?

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 molecules are in 6.0 moles of methane