Express the equilibrium constant expression for the following reaction:                  4 Al(s) + 3 O2(g)   ⇌  2 Al2O3(s)  

Nitrous acid, HNO2, is a weak acid in water (pKa = 3.35). If an aqueous solution of nitrous acid with pH 2.69 is required, what concentration, in M, of the acid is needed? Enter your numerical answer to 4 decimal places and without units.

A chemical engineer is studying the following reaction: CH4(g) + 2H2S(g) → CS2(g) + 4H2(g) At the temperature the engineer picks, the equilibrium constant, Kp, for this reaction is 31. The engineer fills the reaction vessel with methane and hydrogen sulfide, and lets the reaction begin. He then measures the composition of the mixture inside each vessel from time to time. His first set of measurements show that there are 9.59 atm CH4, 6.70 atm H2S, 7.54 atm CS2, and 8.52 atm H2. Predict the changes in the compositions the engineer should expect next time he measures the compositions. Select all that apply.

The equilibrium constant, Kc, for the reaction PCl3(g) + Cl2(g) ⇌ PCl5 (g) is 49 at 230 ˚C. If 0.70 mol of PCl3 is added to 0.70 mol of Cl2 in a 1.00-L reaction vessel at 230 ˚C, what is the concentration, in mol/L, of PCl3 when equilibrium has been established? Enter a number, to 3 significant figures, and without units.

Phosphoric acid has Ka1 = 7.1 × 10−3; Ka2 = 6.3 × 10−8; Ka3 = 4.2 × 10−13 . For a 3.0 M H3PO4 solution, the [PO4−3] is closest to

Select the correct definition of the word: hypercapnia

When trying to create a new term, where should you start first?

A combining form for “cartilage” is:

What is the term for the discharge of pus?

What does the transverse plane divide the body into?