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Which one of the following is the weakest acid?

HNO2 (Ka = 4.5 × 10-4) HCN (Ka = 4.9 × 10-10)*** HF (Ka = 6.8 × 10-4) HClO (Ka = 3.0 × 10-8)

At 25°C, the value of Kw is

1.00 × 10-14.

Write balanced equation for proton-transfer reaction between HCl and PO43−.

HCl(aq)+PO43−(aq)⇌HPO42−(aq)+Cl−(aq)

Consider the following reaction: NO2 - + HCO3 - ⇌ CO3 2- + HNO2 Identify the acid, base, conjugate acid and conjugate base.

Acid: HCO3 -; base: NO2 -; conjugate acid: CO3 2-; conjugate base: HNO2

Choose a balanced equation for the transfer of a proton between dihydrogen phosphate ion and the hydroxide ion.Identify the conjugate acid-base pairs. Refer to the textbook (or E-book) for the definition of a conjugate acid-base pair.Determine which side of the reaction is favored

H2PO4 -(aq) + OH-(aq) ⇌ HPO4 2-(aq) + H2O(l) OH- and H2O H2PO4 - and HPO4 2- products

Which one of the following weak acids is the strongest?

HCN (Ka = 4.9 × 10-10) HF (Ka = 6.8 × 10-4) HNO2 (Ka = 4.5 × 10-4)**** HClO (Ka = 3.0 × 10-8)

Write balanced equation for proton-transfer reaction between HCN and SO42−. See note below in bold on how to enter the reaction equation - the aqueous phase (aq) must be indicated for all components in the balanced equation. Indicate the conjugate pairs for reaction between HCN and SO42−. Refer to the textbook (or E-book) for the definition of a conjugate acid-base pair.

HCN(aq)+SO42−(aq)⇌HSO4−(aq)+CN−(aq) HCN(aq) weaker acid** SO42−(aq) weaker base** CN−(aq) stronger acid HSO4−(aq) stronger base HCN(aq) weaker base SO42−(aq) weaker acid CN−(aq) stronger base** HSO4−(aq) stronger acid**

Use the hydrogen carbonate ion, HCO3 - to illustrate amphoteric behavior.

HCO3 -(aq) + H3O+(l) ⇌ 2 H2O(aq) + CO3 2-(aq) HCO3 -(aq) + H2O2(aq) ⇌ H2O(l) + HCO4 -(aq) HCO3 -(aq) + H2O(l) ⇌ H3O+(aq) + CO3 2-(aq)**** HCO3 -(aq) + H2O(l) ⇌ OH-(aq) + H2CO3(aq)*****

ndicate the conjugate pairs for reaction between HCl and PO43−. Refer to Chapter 10 in the textbook (or E-book) for the definition of a conjugate acid-base pair. Determine the favored direction for the equilibrium

HCl(aq) stronger base PO43−(aq) stronger acid HCl(aq) stronger acid** PO43−(aq) stronger base** HPO42−(aq) weaker base Cl−(aq) weaker acid HPO42−(aq) weaker acid** Cl−(aq) weaker base** forward

Which of the following is the strongest acid?

HNO3* HCO3- NH4+ H3PO4 H2O

H3PO4(aq)+NH3(aq)→H2PO−4(aq)+NH+4(aq)

NH3(aq) acid NH+4(aq) conjugate acid* NH3(aq) base* H2PO−4(aq) conjugate acid H2PO−4(aq) conjugate base* H3PO4(aq) base H3PO4(aq) acid* NH+4(aq) conjugate base

Which of the following is the weakest acid?

OH- H3PO4*** HCl HNO3 NH3

Sulfuric acid (H2SO4) is a strong acid. Which of the following statements correctly describes its conjugate base?

The conjugate base, H3O+, is a weak base. The conjugate base, SO4 2−, is a weak base. The conjugate base, HSO4 −, is a strong base. The conjugate base, HSO4 −, will have little to no reaction as a base, but it can react as an acid.****

The classification of an acid or a base as weak or strong is determined by

the extent of dissociation of the dissolved acid or base.