SC8: Acids & Alkalis Flashcards
SC8a Acids, Alkalis & Indicators
State the formula for;
A) Hydrochloric, Sulfuric & Nitric Acid
B) Sodium, Potassium & Calcium Hydroxide
A) Acid Formulas
1. Hydrochloric Acid -> HCl
2. Sulfure Acid -> H2SO4
3. Nitric Acid -> HNO3
B) Alkalis Formulas
1. Sodium Hydroxide -> NaOH
2. Potassium Hydroxide -> KOH
3. Calcium Hydroxide -> Ca(OH)2
SC8a Acids, Alkalis & Indicators
Describe the effects of Acids & Alkalines on the following;
A) Litmus Paper
B) Methynl Orange
C) Phenolpthaine
A) Litmus Paper Effects are;
- Acid - Red
- Alkaline - Blue
B) Methyl Orange Effects are;
- Acid - Red
- Alkaline - Yellow
C) Phenolpthaine Effects are;
- Acid - Colourless
- Alkaline - Purple
SC8b Looking at Acids
Describe what is ment by;
A) Concentrated Solution
B) Diliute Solution
A) A Concentrated solution is one that contains a high amount if dissolved solute per unit volume.
B) A Dilute solution contains only a small amount of solute per unit volume.
SC8b Looking at Acids
Describe what is ment by;
A) Strong Acid
B) Weak Acid
A) Their molecules fully dissociate ( break up ) into ions when dissolved in water.
- Producing high concentrations of hydrogen ions.
B) Their molecules do not fully dissociate into ions when dissolved in water.
- Resulting in a lower concentration of hydrogen ions.
SC8c Bases and salts
Describe what is formed when an acid reacts with;
A) Metal
B) Metal Oxide
C) Metal Hydroxides
D) Metal Carbonates
A) Acid + Metal -> Salt + Hydrogen
B) Acid + Metal oxide → Salt + Water
C) Acid + Metal hydroxide → Salt + Water
D) Acid + Carbonate → Salt + Water + Carbon dioxide
SC8c Bases and salts
Describe the test for;
A) Hydrogen
B) Oxygen
C) Carbon Dioxide
A) Squeaky Pop Test - Place a burning splint in a test tube with the gas being tested, if a squeaky pop can be heard, it’s hydrogen.
B) Glowing Splint Test - Place a glowing splint inside of a test tube with the gas, if it relights and bursts into flames it’s oxygen.
C) Lime Water Test - Bubble the gas through limewater, if it turns the limewater milky or cloudy white it’s Carbon dioxide.
SC8e Alkalis and neutralisation
Describe;
A) Why Titration is used when obtaining a neutral solution.
B) How Titration is carried out.
A) If there is to much Acid or Alkaline it could end up contaminating the salt, so using Titration allows us to add them in correct proportions.
B) Method;
1. Acid is added from a burette to a fixed volume of alkali in a conical flask.
- By controlling the flow with the tap, 1 drop can be added at a time.
2. A Pipette is then used to provide an accurate measurement of the alkali.
3. A few drops of indicator are added to the alkali so the neutralisation reaction can be tracked.
- The end-point is when the indicator changes colour.
4. Single indicators ( E.g Methyl Orange ) are used as they provide a single sharp end-point.
SC8g Solubility
A) What is a precipatation reaction?
B) State the solubility rules for common substances.
A) This is a reaction where soluble substances react to form an insolube product.
B1) Soluble in water;
- All common sodium, potassium and ammonium salts
- All nitrates
- Most common chlorides
- Most common sulfates
- Sodium carbonate, potassium carbonate, ammonium carbonate
- Sodium hydroxide, potassium hydroxide, ammonium hydroxide
B2) Insoluble in water;
- Silver chloride, lead chloride
- Lead sulfate, barium sulfate, calcium sulfate
- Most common carbonates
- Most common hydroxides
SC8g Solubility
Describe the method to obtain pure, dry sample of insoluble salts.
1. Mix the 2 solutions containing the soluble salts together in a beaker, then filter the mixture.
2. Rinse the beaker with a little distilled water and pour this through the funnel.
3. Pour a little distilled water over the precipitate in the funnel.
4. Carefully remove the filter paper containing the precipitate and dry it in a warm oven.
