heeey can someone explain to me how to do my hw :(
A. calculate the relative molecular mass of sodium sulfate, Na2SO4.
B. if 12 grams of Na2SO4 is dissolved in water and made up to a total volume of 500 cm3, calculate the concentration of the solution (as molarity i.e. mol dm^-3).
C. how many moles of sodium, Na, would be in 1 dm3 of the solution (b) above?