What is the pH of the solution is 7.9, what is the [OH-]?

show work please.

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure

Ageochemist examines a piece of metal that he found in the soil. he performs tests to identify the metal from its density, electrical conductivity, and melting point. which statement best describes his investigation? a. he is determining physical properties that are sufficient to identify the metal.b. he is determining chemical properties that are sufficient to identify the metal.c. he is determining physical properties that are insufficient to identify the metal.d. he is determining chemical properties that are insufficient to identify the metal.

How is the way a mixture is combined different from how a compound is combined?