The total hardness is due to one or a combination of Ca2 , Mg2 , and Fe2 in your sample. It is convenient to express this hardness as though it was entirely due to Ca2 . Making this assumption, determine the number of moles of Ca2 present in the bottled water sample titrated.

Two people each hold the end of a rope and create waves by moving their arms up and down. this wave is best classified as a transverse wave because a) both the rope particles and the wave are moving in the same direction. b) the wave is moving up and down as the particles of the rope move horizontally. c) the wave is moving horizontally as the particles of the rope move up and down. eliminate d) the wave is moving in a parallel direction with the motion of the person's arms.