C6 Flashcards
What does the pH scale show?
It shows how acidic or alkaline a solution is
- An acid has a pH less than 6
- An alkali has a pH more than 8
- pH 7 is neutral
What do acids produce in water?
They produce hydrogen atoms, H+
When the concentration of H+ ions increases by 10, what happens to the pH level?
Decreases by 1
What makes an acid a ‘strong’ acid?
Strong acids ionise completely in water
What makes an acid a ‘weak’ acid?
Weak acids do not fully ionise in water.
What does an acid and a metal hydroxide form?
Salt + Water
What does an acid and a metal form?
Salt + Hydrogen
What does an acid and a metal carbonate form?
Salt + Water + Carbon Dioxide
How can you make a soluble salt?
Reacting an acid with an alkali.
How can you make an insoluble salt using precipitation?
Reacting 2 soluble salts which produce a precipitate
-e.g. to make lead chloride you mix lead nitrate and sodium chloride which are both soluble
What is the rate of reaction?
How fast the reaction happens
What is the collision theory?
- How often particles collide
- The more frequent the collisions are, the faster the reaction rate is.
- Particles must collide with enough energy for the reaction to take place.
- The more successful collisions, the higher the rate of reaction.
What effect does increasing the temperature have on the rate?
- Particles move faster and have more frequent collisions
- Higher temperatures increase the energy in the reaction, so reactions will be more successful
- Therefore increasing the temperature will increase the rate.
What effect does increasing the concentration/pressure have on the rate?
-There are more particles in the same volume, so collisions are more likely, so the reaction rate increases.
What effect does increasing the surface area have on the rate?
-Particles have more area to react upon (collisions only occur on the surface) so collisions are more likely, so the rate increases.
