Chemical Changes
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Describe how metals react with oxygen and state the compound they form, define oxidation and reduction
Metal + oxygen = metal oxide Oxidation - addition of oxygen (loss of electron) Reduction - removal of oxygen (gain of electrons)
Describe the arrangement of metals in the reactivity series, including carbon and hydrogen, and use the reactivity series to predict the outcome of displacement reactions
Potassium Sodium Lithium Calcium Magnesium Carbon Zinc Iron Hydrogen Copper
Recall and describe the reactions, if any, of potassium with water or dilute acids
Potassium + dilute acid = explosive reaction Potassium + water = a reaction
Recall and describe the reactions, if any, of sodium with water or dilute acids
Sodium + dilute acid = explosive reaction Sodium + water = reaction
Recall and describe the reactions, if any, of lithium with water or dilute acids
Lithium + dilute acid = explosive reaction Lithium + water = reaction
Recall and describe the reactions, if any, of calcium with water or dilute acids
Calcium + dilute acid = explosive reaction Calcium + water = reaction
Recall and describe the reactions, if any, of magnesium with water or dilute acids
Magnesium + dilute acid = moderate reaction Magnesium + water = no reaction
Recall and describe the reactions, if any, of zinc with water or dilute acids
Zinc + dilute acid = moderate reaction Zinc + water = no reaction
Recall and describe the reactions, if any, of iron with water or dilute acids
Iron + dilute acid = moderate reaction Iron + water = no reaction
Recall and describe the reactions, if any, of copper with water or dilute acids
Copper + dilute acid = no reaction Copper + water = no reaction
Relate the reactivity of metals to its tendency to form positive ions and be able to deduce an order of reactivity of metals based on experimental results
The more reactive metals form positive ions more easily, this also means they react with water and acid easily
Recall what native metals are and explain how metals can be extracted from the compounds in which they are found in nature by reduction with carbon
Native metals - a pure metal in its metallic form in nature Potassium, sodium, lithium, calcium and magnesium can be extracted from compounds using electrolysis. Zinc, iron and copper can be extracted from their oxides using carbon.
HT ONLY: Describe oxidation and reduction in terms of loss and gain of electrons
Oxidation - loss of electrons Reduction - gain of electrons
HT ONLY: Write ionic equations for displacement reactions, and identify which species are oxidised and reduced from a symbol or half equation
Mg(s) + Zn2+(aq) = Mg2+(aq) + Zn(s) Oxidation - Mg = Mg2+ + 2e- Reduction - Zn2+ + 2e- = Zn
Explain that acids can be neutralised by alkalis, bases and metal carbonates and list the products of each of these reactions
H+ + 0H- = H20 Acid + alkali = water (neutral) Acid + metal carbonate = salt + water + carbon dioxide Acid + metal oxide = salt + water Acid + metal hydroxide = salt + water
Predict the salt produced in a neutralisation reaction based on the acid used and the positive ions in the base, alkali or carbonate and use the formulae of common ions to deduce the formulae of the salt
HCl - chloride H2SO4 - sulfate HNO3 - nitrate
Describe how soluble salts can be made from acids and how pure, dry samples of salts can be obtained
Soluble salts are made from adding metals and insoluble metal compounds to acids. The excess solid is filtered and remaining salt solution if crystallised.
Recall what the pH scale measures and describe the scale used to identify acidic, neutral or alkaline solutions
The pH scale measures what pH the substance is in terms of how acidic or alkaline it is or if it’s neutral.
Define the terms acid and alkali in terms of production of hydrogen ions or hydroxide ions (in solution), define the term base
Acid - pH less than 7, produces H+ ions in water Alkali - pH more than 7. produces OH- ions in water Base - a substance with a pH higher than 7
Describe the use of universal indicator to measure the approximate pH of a solution and use the pH scale to identify acidic or alkaline solutions
The universal indicator changes colour depending on the pH - it gives an approximate value. You can use the pH scale to use the colour the universal indicator provides to identify the exact pH.
HT ONLY: Use and explain the terms dilute and concentrated (in terms of amount of substance) and weak and strong (in terms of the degree of ionisation) in relation to acids
Dilute - low concentration (low amount of particles) Concentrate - high concentartion (high number of particles) Weak acid - partially ionises in water to produce hydrogen ions. Strong acid - completely ionises in water to produce hydrogen ions
HT ONLY: Explain how the concentration of an aqueous solution and the strength of an acid affects the pH of the solution and how pH is related to the hydrogen ion concentration of a solution
The pH will be lower if there is a higher concentration.
Describe how ionic compounds can conduct electricity when dissolved in water and describe these solutions as electrolytes
Ionic compounds can conduct electricity when in electrolytes due to the electrons being free to move and carry charge.
Describe the process of electrolysis
Electrolysis - the process in which a ionic compound is broken down into its elements using a electrical current