Help asap please. A solution contains an unknown mass of dissolved barium ions. When sodium sulfate is added to the solution, a white precipitate forms. The precipitate is filtered and dried and then found to have a mass of 217 mg. What mass of barium was in the original solution? (Assume that all of the barium was precipitated out of solution by the reaction.)

Which statement describes the appearance of a temperature-vs.-time graph? a horizontal line shows that the temperature increases at a constant rate over time. a vertical line shows that the temperature decreases at a constant rate over time. horizontal lines where the temperature is constant during phase changes connect upward-sloping lines where the temperature increases. horizontal lines where the temperature increases are connected by upward-sloping lines where the temperature is constant for each phase.

Consider the following reaction at equilibrium. 2co2 (g) 2co (g) + o2 (g) h° = -514 kj le châtelier's principle predicts that the equilibrium partial pressure of co (g) can be maximized by carrying out the reaction a. at high temperature and high pressure b. at high temperature and low pressure c. at low temperature and low pressure d. at low temperature and high pressure e. in the presence of solid carbon

Glucose (c6h12o6) is an important biological molecule. (round the answer to nearest hundredth.) what is the percent by mass of carbon in glucose?