Question

1. Write a balanced equation for the neutralization of stomach acid by NaHCO3.

Express your answer as a chemical equation. Identify all of the phases in your answer

2. Based on the Ka values in the table, rank the following solutions in order of decreasing pH: 0.10 M HCOOH, 0.10 M HF, 0.10 M H2CO3, 0.10 M HSO4−, and 0.10 M NH4+.

Rank from highest to lowest. To rank items as equivalent, overlap them.

HCOOH

HF

H2CO3

HSO4−

NH4

Acid	Ka
Hydrofluoric acid (HF)	3.5×10−4
Hydrocyanic acid (HCN)	4.9×10−10
Ammonium ion (NH4+)	5.6×10−10
Organic acids
Formic acid (HCOOH)	1.8×10−4
Acetic acid (CH3COOH)	1.8×10−5
Propanoic acid (CH3CH2COOH)	1.3×10−5
Ascorbic acid (vitamin C)	7.9×10−5
Polyprotic acids
Sulfuric acid
H2SO4	Large
HSO4−	1.2×10−2
Phosphoric acid
H3PO4	7.5×10−3
H2PO4−	6.2×10−8
HPO42−	2.2×10−13
Carbonic acid
H2CO3	4.3×10−7
HCO3−	5.6×10−11

Answer 1