Acids, Alkalis And Salts Flashcards
use the pH scale to identify acidic, alkaline and neutral substances.
Acidic - ph < 7
Neutral - ph = 7
Alkaline - ph > 7
use universal indicator and a pH probe to measure the approximate pH of a solution.
Universal Indicator: A mixture of dyes that changes color across the pH scale. Colors: Red (strong acid), orange/yellow (weak acid), green (neutral), blue (weak alkali), purple (strong alkali).
pH Probe - An electronic device that measures the exact pH of a solution.
describe how to use universal indicator, litmus,
phenolphthalein and methyl orange to distinguish between acidic and alkaline solutions.
Universal Indicator: Full pH range with different colors.
Red Litmus: Turns blue in alkaline solutions.
Blue Litmus: Turns red in acidic solutions.
Phenolphthalein: Colorless in acidic solutions, pink in alkaline solutions.
Methyl Orange: Red in acidic solutions, yellow in alkaline solutions.
define neutralisation.
A chemical reaction in which an acid and a base react to form a salt and water.
describe the difference between alkalis and bases.
Bases - Substances that can neutralize acids to form a salt and water. Examples include metal oxides, hydroxides, and carbonates.
Alkalis - Bases that dissolve in water to release hydroxide ions (OH^-). Examples include sodium hydroxide (NaOH) and potassium hydroxide (KOH).
recognise metal oxides, metal hydroxides and ammonia as bases.
Metal Oxides: Examples include MgO, CaO.
Metal Hydroxides: Examples include NaOH, KOH.
Ammonia: NH_3, which in water forms NH_4OH.
explain how filtration can be used to separate mixtures containing an insoluble solid.
Separates an insoluble solid from a liquid. Example: Separating sand from water.
explain how crystallisation can be used to separate mixtures containing a soluble solid.
Separates a soluble solid from a solution by evaporating the solvent. Example: Crystallizing salt from saltwater.
define the terms solvent, solute, solution and saturated solution.
Solvent - The substance that dissolves the solute. E.g. water
Solute - The substance that is dissolved in the solvent. E.g. salt
Solution - A homogeneous mixture of solute and solvent. E.g. salt water
Saturated Solution - A solution in which no more solute can dissolve at a given temperature
describe an experiment to prepare a pure, dry sample of a soluble salt, starting from an insoluble reactant.
Preparing copper(II) sulfate from copper(II) oxide and sulfuric acid.
Add copper(II) oxide to sulfuric acid and warm the mixture until no more reacts. Filter out the unreacted copper(II) oxide. Evaporate the filtrate to obtain copper(II) sulfate crystals.
prepare a sample of pure, dry hydrated copper(Il) sulfate crystals using copper(Il) oxide.
Warm sulfuric acid in a beaker. Add copper(II) oxide gradually, stirring until no more dissolves. Filter the mixture to remove excess copper(II) oxide. Evaporate the filtrate to concentrate the solution. Leave the solution to cool and crystallize. Filter the crystals and dry them.
Neutralisation word equations
Acid + metal > metal salt + hydrogen
Acid + metal oxide > metal salt + water
Acid + metal hydroxide > metal salt + water
Acid + metal carbonate > metal salt + water + co2
Amount of carbon atoms for hydrocarbons
Methane - 1
Ethane - 2
Propane - 3
Butane - 4
Pentane - 5
