2.1.4 acids Flashcards
What do acids and alkalis release in aqueous solutions?
In aqueous solutions, acids will release H+ ions and alkalis will release OH- ions.
What is the difference between a strong and a weak acid?
Strong acids will completely dissociate all it’s H+ ions in an aqueous solution, whereas a weak acid will only partially dissociate.
What is a base?
A base neutralises an acid to form a salt.
What three common bases?
NaOH-Sodium hydroxide
KOH-Potassium hydroxide
NH3-Ammonia
What are four common acids?
HCI-Hydrochloric acid
H2SO4-Sulfuric acid
HNO3-Nitric acid
CH3COOH-Ethanoic acid
What is the reaction between an acid and a metal oxide/hydroxide?
Acid + metal oxide/hydroxide —> salt + water.
What is the reaction between an acid and a carbonate?
Acid + carbonate —> salt + water + CO2.
What is a titration?
A titration is a method used to measure the volume of one solution that reacts exactly with another solution.
What is a standard solution?
A standard solution is a solution of known concentration.
How do you prepare a standard solution?
1) solid is weighed accurately
2) solid is dissolved in a beaker using distilled water
3) solution transferred to volumetric flask-last traces are rinsed using distilled water.
4) flask filled to graduation line by adding distilled water by the drop.
5) volumetric flask is inverted several times to mix the solution thoroughly.
How do you carry out an acid-base titration?
1) add measured volume of one solution to a conical flask using a pipette
2) add the other solution to a burette, record the initial burette reading to nearest 0.05cm3
3) add a few drops of indicator to the conical flask solution.
4) run the solution in the burette into the conical flask, swirling the conical flask.
5) indicator colour change to indicate end point
6) record the final burette reading
7) repeated more accurately than the trial titre.
How do you work out an unknown concentration (titration) ?
1) work out the amount, in mol, of the solute in the solution which the concentration and volume is known for.
2) use the equation to work out amount, in mol, of the solute in the other solution.
3) work out the unknown information about the solute in the other solution.
What is the practical for identifying a carbonate?
1.prepare unknown solution of X2CO3.
2.measure 25cm^3 of solution.
3.titrate solution with 0.1 mol dm^-3 HCl.
4.analyse results.
What is the calculation for the practical for identifying an unknown carbonate?
1.n(HCl)=c x v/1000
2.use equation to determine amount of X2CO3 reacted.
3.scale up (x10) to find amount of X2CO3 in 250cm^3 solution.
4.find molar mass of X2CO3 in 250cm^3 solution- M(X2CO3)=m/n
5.use M(X2CO3) to identify formula of X2CO3.
