Reactions of Acids Flashcards
what does a reaction between a metal and an acid produce
metal + acid = salt + hydrogen
what is the condition that has to be met in order for a metal + acid reaction to take place
- the metal has to be sufficiently reactive
- such as Mg being able to react
- but Cu not being able to
what is the salt that is formed and what does this property imply about its state
- it is soluble
- so it is in an aqueous state when produced
what would always be visually seen during this reaction
bubbles of hydrogen gas escaping from the solution
what would the equation for Mg and 2HCl reacting together
Mg + 2HCl = MgCl2 + H2
why can these reactions be called neutralisation reactions
- because the H+ ions are removed from the water
- apart from the very small numbers present in water
what type of reactions are these, also, and why
- redox reactions
- because there is a transfer of electrons from the Mg to the H+ ions
- or in general terms, from the metal to the H+ ions
what is the general equation for the reaction between a metal oxide and an acid
metal oxide + acid = salt + water
what is the general equation for the reaction between a metal hydroxide and an acid
metal hydroxide + acid = salt + water
why does the reactivity of the metal not matter in these reactions
- because the metal in the reactant is present as metal ions, not atoms
- this is due to it being in a solution, making it aqueous
what would you visually observe from these reactions
usually just the formation of the product / solution
what would be the equation for the reaction between CuO and H2SO4
CuO + H2SO4 = CuSO4 + H2O
what would be the equation for the reaction between Zn(OH)2 and H2SO4
Zn(OH)2 + H2SO4 = ZnSO4 + 2H2O
what type of reactions are these and why
- neutralisation reactions
- because the H+ ions react with the O2- ions or the OH- ions
- producing water
why arent these reactions redox reactions
because there isnt a change in the oxidation number of any of the species
what is the general equation for the reactions between acids and alkalis
metal hydroxide + acid = salt + water
if there are no visible changes during these reactions, what could you do to see whether a reaction is occurring
- put a thermometer in the solution
- a rise in temperature should be detected
what are the three typical equations for the reaction between NaOH and H3PO4, phosphoric acid
- NaOH + H3PO4 = NaH2PO4 + H2O
- 2NaOH + H3PO4 = NaHPO4 + 2H2O
- 3NaOH + H3PO4 = NaPO4 + 3H2O
what does the type of reaction between sodium hydroxide and phosphoric acid that occurs depend on
the relative amounts of them used
what is the ionic equation for this reaction
H+ + OH- = H20
what does that ionic equation imply about the reaction
- it is a neutralisation reaction
- as the H+ ions and OH- ions react and neutralise each other
- but it is not a redox reaction
what is the general equation for the reaction between acids and metal carbonates
metal carbonate + acid = salt + water + carbon dioxide
what are the two things that are practically formed
- bubbles of carbon dioxide gas
- and a solution if the salt is soluble
what is the equation for the reaction between LiCO3 and 2HCl
LiCO3 + 2HCl = LiCl2 + CO2 + H2O
what types reactions are these
- neutralisation reactions
- because the H+ ions react with the CO2- ions
- to form CO2 and H2O
- but they are not redox reactions as there is no change in the oxidation number of any species
what are hydrogencarbonates
compounds containing the hydrogencarbonate ion HCO3-
what general equation is the reaction between H-carbonates and acids identical to in terms of products
the equation for a metal carbonate + acid
what is the most common H-carbonate
- sodium hydrogencarbonate
- NaHCO3
- also known as baking soda or bicarbonate of soda
why is baking soda used in baking and why does it cause the effect it does
- because it causes the food to rise and become light
- this is due to the formation of bubbles of carbon dioxide in the bake mixture
what does the baking soda react with in the food generally
citric acid
what is the general equation for the reaction between sodium hydrogencarbonate and citric acid
sodium hydrogencarbonate + citric acid = sodium citrate + water + carbon dioxide
what is the test for the presence of carbonate or hydrogencarbonate ions in a solid or solution
- add an aqueous acid
- and test the gas given off with limewater
- if it turns cloudy it is CO2
- meaning the ions are present
