EL.9 Flashcards
Reacting masses, acids and bases, neutralisation, and concentration of solutions
What are group 2 oxides and hydroxides?
Bases, meaning they can react with acids to form salts.
What are some key properties of acids?
- They turn litmus red.
- They react with carbonates to give off carbon dioxide.
- They can be neutralized by bases.
What causes acids to have the properties they have on an atomic level?
Their ability to transfer H+ ions to something else.
An acid is said to be a proton what?
Proton donor.
A base is said to be a proton what?
Proton acceptor.
What is a reaction called when it involves a substance donating H+ to a substance which accepts it?
An acid-base reaction.
What is a hydrochloric acid?
A solution of hydrogen chloride (gas) dissolved in water, forming an acidic solution.
What is the oxonium ion?
H3O+
What is the reaction where the acid donates H+ to water (which behaves as a base), to form H3O+?
H+(aq) + H2O(l) → H3O+(aq)
What is the ion that actually acts as an acid and makes solutions acidic?
The oxonium ion, H3O+, it donates H+ to become H2O, it is the ion that cause the properties of acidic solutions. However it is typically just shorten and simplified to H+.
What is the reaction for the dissociation of HCl solution into its ions?
HCl(aq) → H+(aq) + Cl-(aq)
What is an alkali?
An alkali is a base that dissolves in water to produce hydroxide ions, OH-.
Where do hydroxide ions come from in an alkaline solution?
Some alkalis, such as the metal hydroxides already contain hydroxide ions, whereas other alkalis, form hydroxide ions when they react with water.
What is the ionic equation for a neutralization reaction which produces water? Using sodium hydroxide and hydrochloric acid as an example.
H+(aq) + OH-(aq) → H2O(l)
What is the ionic equation for a neutralization reaction which produces salt? Using sodium hydroxide and hydrochloric acid as an example.
Na+(aq) + Cl-(aq) → NaCl(aq)
What type of salt is formed in a precipitation reaction?
Insoluble salt.
What do you have to do to be able to find out the concentration of acid or base in a reaction, when know only the concentration of one of the reactants?
- Dilute a solution.
- Make up a standard solution.
- Carry out an acid-base titration.
What is concentration normally measured?
g/dm3, or gdm-3.
What information do you also need if you want to convert a concentration in moldm-3 to gdm-3 or vice versa?
The molar mass of the substance involved.
What is the equation for converting concentration units?
concentration (moldm-3) = concentration (gdm-3) / molar mass (gmol-1)
When making a solution, what are the two things the concentration of the solution will depend on?
- The amount of solute used.
2. The final volume of the solution.
How do you work out the amount of solute used in a solution?
amount of solute (g or mol) = concentration (gdm-3 or moldm-3) x volume of solution (dm3)
What equations link concentration, amount of solute and volume of solution?
concentration c = amount n / volume V
volume V = amount n / concentration c
amount n = concentration c x volume V
