5.20 kJ of heat is required to convert a 9.00 g sample of aldehyde from the liquid to gas phase. The heat that is
required to convert an 18.0 g sample of aldehyde from the
liquid to gas phase is required to convert 26.4 g sample of
benzene from the liquid to gas phase. What is the heat of
vaporization of benzene in J/g?
J/g

Asolution at 25 degrees celsius is 1.0 × 10–5 m h3o+. what is the concentration of oh– in this solution?

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.)

Seltzer water is created by placing water under pressure with carbon dioxide gas. which of the following statements best describe seltzer water: a. the solution will be slightly acidic b. the solution will be slightly basic. the solution will be strongly acidic. d. the solution will be strongly basic. e. the solution will be neutral