Which of the following is not an observable clue that a chemical reaction has occurred? a. release of a gas
b. color change
c. formation of a precipitate
d. mixing of the reactants

Aluminum–lithium (al-li) alloys have been developed by the aircraft industry to reduce the weight and improve the performance of its aircraft. a commercial aircraft skin material having a density of 2.47 g/cm3 is desired. compute the concentration of li (in wt%) that is required.

Asolution of sodium hydroxide was titrated against a solution of sulfuric acid. how many moles of sodium hydroxide would react with 1 mole of sulfuric acid?

In a laboratory, 1.55mg of an organic compound containing carbon, hydrogen, and oxygen is burned for analysis. this combustion resulted in the formation of 1.45mg of carbon dioxide and .89 mg of water. what is the empirical formula for this compound?