Acids and Bases Flashcards
What are Brønsted–Lowry acids?
proton donors
What are Brønsted–Lowry bases?
proton acceptors
What are strong acids?
What are strong bases?
Bases that completely ionise in water.
What are weak acids?
What is the ionic product of water?
Why do we consider the concentration of the water a constant?
There is so much water compared to hydrogen and hydroxide ions that the water can be considered to have a constant concentration.
What equation do you use to find the hydrogen concentration of pure water?
1.00 × 10–14
What are the equations that link pH and hydrogen ion concentration?
Calculate the pH of 0.10 mol dm–3 hydrochloric acid.
Calculate the pH of 0.100 mol dm–3 sulfuric acid.
The value of Kw at 298 K is 1.0 × 10–14 mol2 dm–6. Find the pH of 0.100 mol dm–3 NaOH at 298 K
What is the acid dissociation constant?
Find the pH of a 0.020 mol dm–3 solution of propanoic acid (CH3CH2COOH) at 298K. Ka
for propanoic acid at this temperature is 1.30 × 10–5 mol dm–3
How do you find pKa?
How do you find Ka using pKa?
How do you find pH using Ka?
pH = pKa
How to identify which indicator to use?
The pH range must lie entirely on the vertical point of the titration curve.
What is a buffer?
A solution that resists changes in pH when a small amount of acid or alkali is added.
What are acidic buffers made out of?
- A weak acid and a strong base.
- A weak acid and one of its salts.
What effect does adding an acid have on an acidic buffer?
- The H+ concentration increases.
- The excess H+ ions combine with the A- ions and the equilibrium shifts to the left.
- This causes the H+ concentration to decrease.
What effect does adding an alkali have on an acidic buffer?
- The OH- concentration increases and H+ decreases.
- The excess OH- ions react with the H+ ions to form water.
- The equilibrium shifts to the right so that the acid dissociates to release more H+ ions.
What are basic buffers made out of?
A weak base and one of its salts.
What effect does adding an acid have on an acidic buffer?
- The H+ concentration increases and OH- decreases.
- The excess H+ ions react with the OH- ions to form water.
- The equilibrium shifts to the right so more of the base dissociates to release OH- ions.
What effect does adding an alkali have on an acidic buffer?
- The H+ concentration decreases and the OH- concentration increases.
- The excess OH- ions will react with the positive ion to make H2O and the equilibrium shifts to the left to remove the OH- ions.
