Chapter 4 acid and redox Flashcards
What is the formula for phosphoric acid?
H3PO4
What is the formula for nitric acid?
HNO3
What is the formula of sulfuric acid ?
H2SO4
What is the formula of hydrochloric acid?
HCl
What happens to acids when dissolved in water?
They have free moving H+ ions
Define acids
A compound that releases hydrogen ions (H+ protons) in aqueous solution
A strong acid fully …….. in aqueous solution to release ……. ions
Disassociates
H+
A weak acid will ……. dissociate in aqueous solution
Partially
What are bases?
Metal carbonate Metal hydroxides Metal oxides Ammonia Amine
A substance that accepts hydrogen ions from an acid
What is an alkali ?
A soluble base. A compound that gives a solution with a pH greater than 7 when dissolved in water. It releases OH- in aqueous solutions
A strong alkali will
Undergo complete dissociation
What is the ionic equation for neutralisation?
H+ + OH- ——> H20
What are spectator ions in a neutralisation reaction?
Any ions that are not H+ or OH-
Acid + base——>
Salt and water
Acid+alkali ——->
Salt + water
Acid + metal carbonate ———>
Salt + water + carbon dioxide
Acid + metal ——>
Salt + hydrogen
Define concordant results
Results within 0.1cm3 of each other
What is the importance of rinsing a conical flask with distilled water while using it for a titration ?
Ensures all acid/alkali/ reactants are in the solution as it couldve been in the sides of the flask
Why does adding distilled water to the conical flask not change the concentration value?
The added water doesnt change the number of moles of acid/alkali in the solution so the concentration doesnt change
State why it is important to fill the space below the tap in the Burrett with solution before beginning an accurate titration?
The space will fill during the titration so the volumes added are too low
Suggest why a 250cm3 conical flask is preferred to a 250cm3 beaker for titrations
Less chance of loosing liquid on swirling
State the calculation to work out the concentration of a solution in moldm-3
Moles/volume (dm3)
What is the equation for working out the concentration of a solution in gdm-3?
Mass/volume (dm3)
How do you convert from moldm-3 to gdm-3?
Multiply by Mr
State the percentage uncertainty equation
Maximum uncertainty/value of measurement
X100
State the method for preparing a standard solution
Weight the solid accurately in a weighing boat on scales and pour into a beaker.
Wash the boat with distilled water and add rhe washings to the beaker
Get a 250cm3 volumetric flask and place a funnel in it
Transfer solution to flask
Wash beaker, funnel and glass rod and add washings to flask
Fill flask with distilled water until the bottom of the miniscus reaches the graduation mark
Invert several times
