For a solution containing 6.38% para-diclorobenzene by mass in benzene, the density of the solution as a function of temperature (t) in the temperature range 15 to 65°c is given by the equation, rho(g/ml) = 1.5794 – 1.836x10-3 (t-15). at what temperature will the solution have a density of 1.543 g/ml?

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)

Which would freeze at a higher temperature: the great salt lake or lake tahoe? a. lake tahoe would freeze at a higher temperature. b. the great salt lake would freeze at a higher temperature. c. both lakes would freeze at the same temperature.