acids and bases

are acids proton donors or proton acceptors?

proton donors

are alkalis proton donors or proton acceptors?

proton acceptors

what are bases which are soluble in water known as?

alkalis

what ions do acids produce in aqueous solution?

H+ ions in aqueous solution

what ions do alkali’s produce in aqueous solution?

OH- ions in aqueous solution

state 4 common acids?

• HCL-hydrochloric acid

• H2SO4- sulfuric acid

• HNO3-nitric acid

• CH3COOH- ethanoic acid

state 3 common bases?

• NaOH- sodium hydroxide

• KOH- potassium hydroxide

• NH3- ammonia

what type of reaction is between acids and water or bases and water?

reversible

what happens when strong acids react with water?

• forward reaction is favoured

• nearly all of the acid will dissociate in water

• nearly all the H+ are released

example of a strong acid?

hydrochloric acid

what happens when strong bases react with water?

• forward reaction is favoured

• nearly all the base dissociates in water

• lots of OH- ions are released

example of strong bases?

sodium hydroxide

what happens when weak acids react with water?

• the backwards reaction is favoured

• small amount of the acid dissociates in water

• few H+ ions are released

example of weak acid?

ethanoic acid

what happens when weak bases react with water?

• backwards reaction is favoured

• small amount of the bases dissociates

• few OH- ions are released

state the name of the reaction where acids and bases neutralise each other to form neutral salts?

• neutralisation reaction

what does an acid + alkali produce?

salt + water

what does a metal + acid produce?

metal salt + Hydrogen

what does a metal oxide + acid produce?

salt + water

what does a metal hydroxide + acid produce?

salt + water

what does a metal carbonate + acid produce?

metal salt + carbon dioxide + water

what does ammonia + acid produce?

ammonium salt

what do titrations allow you to find out?

exactly how much acid is needed to neutralise a quantity of an alkali

what titration should be carried out first?

a rough titration to get an idea of where the end point is

what does a pipette measure?

only one volume of solution

what does a burette measure?

different volumes of solution

define the end point?

where the alkali is exactly neutralised and the indicator changes colour

where should readings of the burette be taken from?

from the bottom of the meniscus

state the main 2 indicators used for acid alkali reactions?

• methyl orange- turns yellow to red when adding acid to alkali

• phenolphthalein- turns pink to colourless when adding acid to alkali

what should a titration be carried over by to clearly see the end point/ colour change?

• a white tile

what is the name given to the solution you precisely know the concentration of?

• the standard solution

steps to create standard solution?

• use a precise balance to weigh the mass of solid

• transfer solid to a beaker and use water to wash away any excess solid

• add water to the beaker to completely dissolve the solid

• use a glass rod to stir the solution to help dissolve

• once the solid has dissolved, transfer the solution into a volumetric flask

• rinse the beaker and glass rod transferring this water into the volumetric flask

• use water to fill the volumetric flask up to the graduation line

• put a lid on the flask and turn the flask over a few times to mix the solution

define concentration?

how many moles are dissolved per 1dm3 of solution

conversion of 1dm3 to cm3?

1dm3 = 1000cm3

define the theoretical yeild?

the maximum mass of a product

what difficulties can affect acheiving theoretical yield?

• the reaction may not have been complete

• side reactions may have taken place

define actual yield?

what is obtained by the reaction

what is the actual yield always less than?

less than the theoretical yield

percentage yield equation?

actual yield/ theoretical yield times 100

define limiting reagent?

a reactant that is totally consumed when the chemical reaction is completed

what is atom economy a measure of?

efficiency, how well atoms have been utilised

atom economy equation?

(molar mass of desired product/ molar masses of all products) times 100

define key points on why it is important to develop sustainable reactions?

• low atom economies produce many waste products

• costly to dispose of waste products safely so that they don’t harm the environment

• reactant products are expensive so waste of money if high proportion ends up as useless product

• lower temps and pressures are cheaper to run and better for the environment

what do oxidation numbers in neutral compounds add up to?

• oxidation numbers in neutral compounds must add up to 0

what is the oxidaton number of oxygen?

oxygen has an oxidation number of -2

how to calculate oxidation number of an ion?

in an ion, all the oxidation numbers must add up to the charge of the ion

what is the oxidation number of free elements

free elements have an oxidation number of 0

what is the oxidation number of fluorine?

the oxidation number of fluorine is -1

what does the oxidising agent accept?

the oxidation agent accepts electrons and gets reduced

what does the reducing agent donate?

the reducing agent donates electrons and gets oxidised