How many moles of NiCl_2 can be formed in the reaction of 6.00 mol of Ni and 12.0 mol of HCl?

The oxidation of chromium solid is represented by the following equation: 

How many moles of chromium (III) oxide are produced when 34.69 g Cr reacts with excess oxygen gas? 

The reaction of potassium chlorate and sucrose is given below: 

If 2.33 x 10^-7 formula units of potassium chlorate are reacted, how many grams of carbon dioxide will be produced? 

If the density of ethanol, CH₃CH₂OH, is 0.789 g/mL, how many milliliters of ethanol are needed to produce 4.8 g of H₂O in the following reaction?