The diagram provided here shows the reactants and the products of a common chemical reaction. The line on the graph behind them represents the energy of a system as the reaction progresses. Which of the following conclusions is best supported by the information provided? O Because there was a change in energy, the equation must not be balanced
O the overall mass of the system increased when the reaction occurred
O This reaction required the addition of energy from the surroundings
O During the reaction the energy was converted to mass, and, therefore, was lost

A0.10 m aqueous solution of sodium sulfate is a better conductor of electricity than a 0.10 m aqueous solution of sodium chloride. which of the following best explains this observation? (a) sodium sulfate is more soluble in water than sodium chloride. (b) sodium sulfate has a higher molar mass than sodium chloride. (c) to prepare a given volume of 0.10 m solution, the mass of sodium sulfate needed is more than twice the mass of sodium chloride needed. (d) more moles of ions are present in a given volume of 0.10 m sodium sulfate than in the same volume of 0.10 m sodium chloride. (e) the degree of dissociation of sodium sulfate in solution is significantly greater than that of sodium chloride.