Ionic bonding review sheet for chemistry

How many moles of oxygen react with 12 moles of aluminum

To prevent the presence of air, noble gases are placed over highly reactive chemicals to act as inert "blanketing" gases. a chemical engineer places a mixture of noble gases consisting of 4.37 g of he, 13.36 g of ne, and 36.65 g of kr in a piston-cylinder assembly at stp. calculate the partial pressure in torr of kr.

How many moles of potassium are needed to react completely with 12.8 moles of magnessium bromide?