Is PBr5 a lewis acid or base?

Classify each of the following substances as an acid, a base, or a salt. a. HBr b. NaI c. NH4NO3 d. Ba(OH)2

Which acid has the strongest conjugate base? (a) HNO2 (b) C6H5CO2H (c) HCN (d) HCl

. In each of the following chemical equations, identify the conjugate acid-base pairs. a. NH3(aq)+H2O(l)NH4+(aq)+OH(aq) b. PO43(aq)+H2O(1)HPO42(aq)+OH(aq) c. C2H3O2(aq)+H2O(l)HC2H3O2(aq)+OH(aq)

Which of the following conditions indicate an acidic solution? pH = 3.04 (H+| > 1.0 X IO’7 A/ pOH = 4.51 |OH-J = 3.21 X 10"12 M

The pH of a 0.10-M solution of propanoic acid, CH3CH2COOH, a weak organic acid, is measured at equilibrium and found to be 2.93 at 25 °C. Calculate the Ka of propanoic acid.

Classify each of the following as a strong acid, weak acid, strong base, or weak base in aqueous solution. a. HNO2 b. HNO3 c. CH3NH2 d. NaOH e. NH3 f. HF g. h. Ca(OH)2 i. H2SO4

Which of each pair of acids is stronger? Why? (a) HClO3, HClO4 (b) H2S, H2Se

Write chemical equations showing the individual proton-transfer steps that occur in aqueous solution for each of the following acids. a. H2CO3 (carbonic acid) b. H2C3H2O4 (malonic acid)

Hydrazine, N2H4 (having the structure H2NNH2), and its derivatives have been used as rocket fuels. Draw the Lewis electron-dot formula for the hydrazine molecule. Describe the geometries expected about the nitrogen atoms in this molecule. Why would you expect hydrazine to be basic? Which substance, NH3 or N2H4, would you expect to be more basic? Why? Write the chemical equation in which hydrazine reacts with hydrochloric acids to form the salt N2H5Cl. Consider the positive ion of this salt. How does its basic character compare with that of NH3 and N2H4? Explain.