Calculate the mass of potassium bromide needed to react completely with 5.89 L of a 1.64 M Pb(NO3)2 solution. Please specify as to how to do it.

Seawater contains approximately 3.5%nacl by mass and has a density of 1.02 g/ml. what volume of seawater contains 7.5 g of sodium?

Me i dont know what to do! the table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.

Ablock of aluminum is dropped into a graduated cylinder with an initial volume of water at 75ml and the volumes rises to 90ml. if the block has a mass of 40.5 g what is its density ?