Elements of Chemistry: Acids & Bases
1. Water molecules are covalently bonded molecules that are constantly in motion.
2. Water has a tendency to dissociate.
3. COMPLETE THE EQUATION:
2H2O  H3O+ + OH4. Neutral water has the same concentration of [H3O+ ] and [OH-], which is 1 x 10-7mol/L
5. Both are electrolytes, which means that they improve water’s ability to conduct electricity
6. COMPLETE THE EQUATIONS:
HCl + H2O  H3O+ + ClNaOH  Na+ + OH7. Arrhenius defined an acid as any substance that forms hydronium ions in solution.
8. Arrhenius defined a base as any substance that forms hydroxide ions in solution.
9. Bronsted-Lowry defined an acid as any substance that donates a Hydrogen ion, H+(proton)
10. Bronsted-Lowry defined a base as any substance that accepts a Hydrogen ion, H+(proton)
11. Strong acids ionize completely, while weak acids barely ionize at all.
12. What is the difference in the ARROW in the equations for a strong and weak acid? A strong acid only
goes in one direction, a weak acid goes in both directions
13. The pH scale is a logarithmic scale based on hydronium ion concentrations.
14. What are the pH values of the following hydronium ion concentrations?
a. 10-7 = 7
b. 10-2 = 2
c. 10-12 = 12
15. Adding an acid to a pure water solution increases the concentration of hydronium ions, thus lowering
the pH.
16. Adding a base to a pure water solution, the base will bind up hydronium ions, lowering the overall
concentration and raising the pH.
17. Fill in the neutralization equation:
acid + base  water + salt
18. To maintain a healthy pH, many organisms employ a chemical system called a buffer
19. The buffer system in our bodies includes both H2CO3 and HCO3-