Chapter 18 Review Sheet Acids and Bases
- How do acids usually taste? sour
- Name five properties that aqueous acids share.
Electrolytes * react with metals to form H2
Sour taste * react with bases to neutralize
React with indicators
- Give the formula or name for each of the following:
H2SO4 _Sulfuric acid
Nitric Acid _HNO3
H2S _Hydrosulfuric acid
Phosphoric Acid _H3PO4_
- What are the five properties of a base?
Electrolytes * react with acids to neutralize
Bitter taste * slippery feel
React with indicators
- What is the definition of an Arrhenius acid? Give an example of one.
Any compound that contains a hydrogen and ionizes into a hydrogen ion in water-HCl
6. What is an Arrhenius base? Give an example of one?
Any compound that contains a hydroxide and dissociates into a hydroxide ion in water
7.What makes an acid or base strong or weak? An acid or base is strong if it ionizes 100% in water- weak acids and bases do not and you can use % dissociation or KA or KB values to determine their relative strength ( larger the KA or KB value the stronger it is)
8.List the three strong acids that you need to memorize. Hydrochloric acid(HCl), Sulfuric acid (H2SO4) and Nitric acid (HNO3)
9.Explain a weak acid or base. Weak acids and bases have KA and KB values are a % dissociation will accompany them because they do not completely ionizes in water. If you have a strong acid it will produce a weak conjugate base, thus if you have a weak acid it will produce a strong conjugate base; the same holds true for strong and weak bases
10.What is the definition of a Bronsted-Lowry acid? Any compound that donates a hydrogen
11.What is the definition of a Bronsted-Lowry base? Any compound that accepts a hydrogen
12.What is the difference between a monoprotic and a polyprotic acid?
Monoprotic has one hydrogen, while polyprotic has more than one.
13.Label the conjugate acid-base pairs:
a)H3PO4(aq) + NO2-(aq)---- HNO2(aq) + H2PO4-(aq)
acid base c. acid c. base
b) CN-(aq) + HCO3-(aq) --HCN(aq) + CO32-(aq)
base acid c. acid c. base
c)HCN(aq) + SO32-(aq) HSO3-(aq)+ CN-(aq)
acidbase c. acidc. base
d) H2O(l) + HF(aq) F-(aq)+ H3O+(aq)
base acid c. base c. acid
14.Explain why water is considered amphoteric. Water can act as either a weak acid or a weak base
16.Base + Acid ----Salt + Water
17.What occurs during a neutralization reaction? When a strong acid and a strong base react then the solution of salt in water is neutral.
18.Complete and balance the following reactions, and label which resulting solutions would be acidic, basic or neutral.
2HBr +Ba(OH)2 ------à2H2O + BaBr2 Basic
2NaHCO3 +H2SO4 ----à2H2O + 2CO2 + Na2SO4 acidic
HCl +NaOH -----àH2O +NaCl Neutral
Hydrofluoric acid + potassium hydroxide --à water + potassium fluoride-HF + KOH --à H2O + KFBasic
Magnesium + hydrochloric acid ---à Hydrogen gas + magnesium chlorideMg + 2HCl --à H2 + MgCl2
Barium carbonate + nitric acid ---à carbon dioxide + water + barium nitrateBaCO3 + 2HNO3 --à H2O + CO2 + Ba(NO3)2
19.Which of the following solutions would be neutral, acidic or basic?
a)[H+] = 1 x 10 -3- pH = 3 acidic
b)[OH-] = 1 x 10-4 pH = 10 basic
c)pH of 5 - acidic
d)pH of 8- basic
20.A solution contains 4.5 x 10-3 hydrochloric acid. Determine the following:
a) [H3O+] = 4.5 x 10 -3 M
b) [OH] = 1 x 10 -14 / 4.5 x 10 -3 = 2.22 x 10 -12 M
c) pH = -log(4.5 x 10 -3) = 2.35
21.A solution contains 0.025M sulfuric acid. Determine the following:
a)[H3O+]= 2 * 0.025 = 0.05 M
b)[OH-] = 1 x 10 -14 / 0.05 = 2 x 10 -13 M
c)pH = -log ( .05) =1.30
22. A solution contains 0.067 M of sodium hydroxide. Determine the following
a)[H3O+]= 1 x 10-14/ .067 = 1.49 x 10 -13 M
b)[OH-]= 0.067M
c)pOH = 1.17
d)pH= 14 – 1.17 = 12.8
- Ammonia will dissociate at a rate of 20%. What would be the pH, given a 0.78 M solution? Ammonia is a base*
20% = 0.20 * 0.78 = .156 M of [OH-] thus pOH = -log(.156) =.807
pH= 14 - .807 = 13.2
- What is the molarity of a solution of sulfuric acid with a pH of 4.56?
Antilog (-4.56) = 2.75 x 10 -5 but then you have to divide by 2 because sulfuric acid has 2 hydrogens thus 1.38 x 10-5 M
- What is the molarity of a solution of sodium hydroxide with a pH of 11.3? First find the pOH = 14 -11.3 = 2.7 then take the antilog(-2.7)=
2.00 x 10 -3 M
26.What is the molarity of a solution if 45.8 g of sodium hydroxide is added to 750 mL of water? What is its pH?
45.8 g of NaOH / 40g = 1.14 moles/ .750L =1.52 M
thus the –log(1.52) = -.182pOH
14- (-.182) = 14.182 pH
Extra Credit: How many grams of calcium carbonate can be produced, when 235 mL of a 0.444M solution of sodium carbonate reacts with excess calcium nitrate?
Na2CO3 + Ca(NO3)2 --à 2NaNO3 + CaCO3
235 mL ?g
.444M
(.235L) (.444M)= .104 moles of Na2CO3 * the ratio of 1 mole of Na2CO3 to 1 mole of CaCO3 = .104 moles of CaCO3 * 100.g = 10.4 g