1 g of hydrogen is found to combine with 80 g of bromine. 1 g of calcium combines with 4 g of bromine. The equivalent mass of calcium is:
KBr contains 32.9% by weight of potassium. If 6.40 g of bromine reacts with 3.60 g of potassium, calculate the number of moles of potassium which combine with bromine to form KBr.