1. Chapter 8 Acids and Bases
8.6
Reactions of Acids and Bases
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Publishing as Benjamin Cummings

2. Acids and Metals Acids react with metals
such as K, Na, Ca, Mg, Al, Zn, Fe, and Sn.
to produce hydrogen gas and the salt of the metal.
Molecular equations:
2K(s) HCl(aq) 2KCl(aq) + H2(g)
Zn(s) HCl(aq) ZnCl2(aq) + H2(g)

3. Acids and Carbonates Acids react
with carbonates and hydrogen carbonates.
to produce carbon dioxide gas, a salt, and water.
2HCl(aq) + CaCO3(s) CO2(g) + CaCl2(aq) + H2O(l)
HCl(aq) + NaHCO3(s) CO2(g) + NaCl (aq) + H2O(l)

4. Learning Check A. Zn(s) + 2 HCl(aq) B. MgCO3(s) + 2HCl(aq)
Write the products of the following reactions of acids.
A. Zn(s) + 2 HCl(aq)
B. MgCO3(s) + 2HCl(aq)

5. Solution Write the products of the following reactions of acids.
A. Zn(s) + 2 HCl(aq) ZnCl2(aq) + H2(g)
B. MgCO3(s) + 2 HCl(aq) MgCl2(aq) + CO2(g) + H2O(l)

6. Neutralization Reactions
In a neutralization reaction
an acid such as HCl reacts with a base such as NaOH.
HCl + H2O H3O+ + Cl−
NaOH Na OH−
the H3O+ from the acid and the OH− from the base form water.
H3O OH− H2O

7. Neutralization Equations
In the equation for neutralization, an acid and a base produce a salt and water.
acid base salt water
HCl + NaOH NaCl H2O
2HCl + Ca(OH) CaCl H2O

8. Balancing Neutralization Reactions

9. Balancing Neutralization Reactions
Write the balanced equation for the neutralization of
magnesium hydroxide and nitric acid.
STEP 1 Write the acid and base.
Mg(OH)2 + HNO3
STEP 2 Balance H+ in acid with OH- in base.
Mg(OH)2+ 2HNO3
STEP 3 Balance with H2O.
Mg(OH)2 + 2HNO salt + 2H2O
STEP 4 Write the salt from remaining ions.
Mg(OH)2 + 2HNO Mg(NO3)2 + 2H2O

10. Learning Check
Select the correct group of coefficients for each of the
following neutralization equations
A. HCl (aq) + Al(OH)3(aq) AlCl3(aq) + H2O(l)
1) 1, 3, 3, ) 3, 1, 1, ) 3, 1, 1 3
B. Ba(OH)2(aq) + H3PO4(aq) Ba3(PO4)2(s) + H2O(l)
1) 3, 2, 2, ) 3, 2, 1, ) 2, 3, 1, 6

11. Solution A. 3) 3, 1, 1 3 3HCl(aq + Al(OH)3(aq) AlCl3(aq) + 3H2O(l)
B. 2) 3, 2, 1, 6
3Ba(OH)2 (aq) + 2H3PO4(aq) Ba3(PO4)2(s)+ 6H2O(l)

12. Basic Compounds in Some Antacids
Antacids are used to neutralize stomach acid (HCl).

13. Learning Check Write the neutralization reactions for stomach acid
HCl and Mylanta.

14. Solution Write the neutralization reactions for stomach acid
HCl and Mylanta.
Mylanta: Al(OH)3 and Mg(OH)2
3HCl(aq) + Al(OH)3(aq) AlCl3(aq) H2O(l)
2HCl(aq) + Mg(OH)2(aq) MgCl2(aq) + 2H2O(l)

15. Acid-Base Titration Titration Base (NaOH)
is a laboratory procedure used to determine the molarity of an acid.
uses a base such as NaOH to neutralize a measured volume of an acid.
Base (NaOH)
Acid
solution
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Publishing as Benjamin Cummings

16. Indicator An indicator is added to the acid in the flask.
causes the solution to change color when the acid is neutralized.
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Publishing as Benjamin Cummings

17. End Point of Titration At the end point,
the indicator gives the solution a permanent pink color.
the volume of the base used to reach the end point is measured.
the molarity of the acid is calculated using the neutralization equation for the reaction.
Copyright © by Pearson Education, Inc.
Publishing as Benjamin Cummings

18. Calculating Molarity
What is the molarity of an HCl solution if 18.5 mL of a
0.225 M NaOH are required to neutralize 10.0 mL HCl?
HCl(aq) + NaOH(aq) NaCl(aq) + H2O(l)
STEP 1 Given: 18.5 mL of M NaOH; 10.0 mL HCl
Need: Molarity of HCl
STEP mL L moles NaOH moles HCl M HCl
L HCl
STEP 3 1 L = 1000 mL mole NaOH/1 L NaOH
1 mole HCl/1 mole NaOH

19. Calculating Molarity (continued)
STEP 4 Calculate the molarity of HCl.
18.5 mL NaOH x 1 L NaOH x mole NaOH
1000 mL NaOH L NaOH
L moles NaOH
x 1 mole HCl = mole HCl
1 mole NaOH
MHCl = mole HCl = M HCl
L HCl

20. Learning Check H2SO4(aq) + 2KOH(aq) K2SO4(aq) + 2H2O(l) 1) 12.5 mL
Calculate the mL of 2.00 M H2SO4 required to neutralize 50.0 mL of 1.00 M KOH.
H2SO4(aq) + 2KOH(aq) K2SO4(aq) + 2H2O(l)
1) mL
2) mL
3) mL

21. Solution 0.0500 L KOH x 1.00 mole KOH x 1 mole H2SO4 x
1) 12.5 mL
L KOH x 1.00 mole KOH x 1 mole H2SO4 x
1 L KOH mole KOH
1 L H2SO4 x mL = mL
2.00 mole H2SO L H2SO4

22. Learning Check
A 25.0 mL sample of phosphoric acid is neutralized by 42.6 mL of 1.45 M NaOH. What is the molarity of the phosphoric acid solution?
3NaOH(aq) + H3PO4 (aq) Na3PO4(aq) + 3H2O(l)
1) M
2) M
3) M

23. Solution 2) 0.824 M 0.0426 L x 1.45 mole NaOH x 1 mole H3PO4
1 L mole NaOH
= mole H3PO4
mole H3PO4 = mole/L = M L