The Acidic Environment Flashcards
What did Davy propose?
Acids were substances that contained hydrogen atoms that could partially or completely be replaced by a metal. Fault: there were some already acidic metal compounds.
What did Lavoisier’s propose?
Acids were substances that contained oxygen. Fault: many bases had oxygen as well, and some acidic substances contained no oxygen.
What did Arrhenius propose?
Acids ionised to produce hydrogen ions, and bases ionised to produce hydroxide ions. Strong acids ionised completely, and weak acids ionised partially. Fault: some bases did not produce hydroxide ions, didn’t explain basic metallic oxides, or the role of solvents. Acid/base reactions didn’t always produce ions.
What is the Bronsted-Lowry theory?
An acid is a proton donor, and a base is a proton acceptor. (Recognising that a proton is the same as a hydrogen ion). Strong acids had a greater tendency to donate protons, and weak acids had a less tendency. Every acid has a conjugate base, and every base has a conjugate acid. Amphiprotic substances can act as both an acid and a base. Fault: does not explain metallic oxides that have acidic/basic properties.
If a weak acid and a strong base react, is the salt acidic or basic?
Basic, pH > 7.0
If a strong acid and a weak base react, is the salt acidic or basic?
Acidic, pH < 7.0
If a strong base and a strong acid react, what is pH of the salt?
About 7.0, it is neutral
If a weak acid and a weak base react, what is pH of the salt?
About 7.0, it is neutral
What is the molar volume of all gases at 273 K and 100 kPa?
22.71 L
What is the molar volume of all gases at 298 K and 100 kPa?
24.79 L
Why are acids added to food?
To improve taste and preserve the food. Common acids in food are acetic acids (vinegar), citric acid, and ascorbic acid (vitamin C).
How do you calculate pH?
pH equals negative log to the base ten, of the hydronium ion concentration.
pH = -log[H3O+]
How do you calculate the hydronium ion concentration?
Hydronium ion concentration equals ten to the negative pH.
[H3O+] = 10^(-pH)
Calculating pH of basic substances?
The hydronium ion concentration is equal to 10^(-14) divided by the hydroxide ion concentration. pH is then equal to -log to the base 10 of the hydronium ion concentration.
What is a neutral solution in terms of (H3O+)?
[H3O+] = 1.00 x 10^(-7)
