Metals and apparatus Flashcards
Criterion B: 6 questions.
Research questions, hypothesis(with scientific reason), Variables, safety measures (and hazards), materials, procedures.
Weighing machine
Measure the mass of any object, apparatus or chemical in the laboratory.
Stirrer
Magnetic, motor, glass rod, used to mix or to reduce adhesion between sides of the glassware and the contents within.
Electrode
An electric conductor which passes electricity to a non-metallic substance.
Electrochemical cell electrodes
Cathode (entering of electrical charge), Anode (leaving of electrical charge)
Spirit lamp/ Alcohol burner
Used to produce an open flame, made of metals.
Battery
A device consisting of one or more electrochemical cells. Used for powering electrical devices.
When connected to an electric load, a redox reaction converts high energy reactants to low energy products while the energy produced is supplied to the external load or circuit as electrical energy.
Wire clips
Made of plastic. Use to create experimental circuits in the laboratory. The wires with clips are used for solutions only and thus a physical entity can be dissolved in water to check electrical conductivity.
Beakers
A cylindrical glassware/plastic container with a flat bottom with capacities ranging from 1 millimeter to several litres.
Test tube
Also known culture tube or sample tube. A glassware consisting of a finger-like length of glass or clear plastic tube open on one side and rounded and closed on the other.
Usually placed in all-purpose stands.
Multimeter
Also known as multitester/ VOM. Usually can measure voltage, current and resistance.
Conical flask
A titration flask consisting of a conical body, flat bottom and cylindrical neck. Ideal for heating and mixing.
Crucible
A small cup like apparatus about the size of a shot glass made of porcelain or non-reactive material. Used to to contain chemical compounds when heated to extremely high temperature.
Spatula
Small stainless steel apparatus, spoon like curved on one end while flat like rectangular on the other end.
Used for scraping, transferring or applying powders and paste like chemicals or treatments.
Bunsen burner
A small gas burner used in the laboratory for heating combustion and sterilization.
Made up of a metal tube gas intel at the bottom of the tube.
Tripod
Three-legged platform used to support flasks and beakers. Usually made of stainless steel or aluminum for portability in the laboratory.
Wire gauze
Placed over a tripod stand to provide a flat base for glassware. The edges of the wire gauze are often turned inward.
Led bulb
Used in a circuit as a tester for electrical conductivity.
Hand gloves
To prevent burns or rashes on the skin from coming into contact with any of the chemicals.
Cork
Partially inserted in a container to form a seal.
Often made of rubber or wood.
Corks may have holes to allow for thermometers, tubes and other devices without the chemicals leaking out.
Condenser
Used to condense vapours. Used for distillation, reflux and extraction.
Apparatus parts of electrochemical cell.
2 beakers, electrodes, electrolyte, wires, Salt bridge, lamp
Apparatus set up of electrolytic cell
Battery, 1 beaker, electrodes, electrolyte, wires.
Conversion of energy in an electrolytic cell.
Electrical to chemical
Conversion of energy in an voltaic/galvanic cell.
Chemical to electrical.
Reaction in electrolytic cell
A non-spontaneous redox reaction occurs with provision of electrical energy as a catalyst.
Reaction in a voltaic or galvanic cell
Spontaneous reaction where the energy produced in the redox reaction is used to electrical energy.
Physical properties of metals (9)
Low melting point, high density, thermal and electrical conductivity, malleability, high tensile strength, solid/liquid state only, lustrous, ductile
Metal chemical properties (4)
Tendency to donate electrons
Displace hydrogen gas from dilute acids.
React with oxygen to produce ‘basic’ oxides.
React with hydrogen to produce hydrides.
Sodium and chlorine reaction setup
Rounded flask with chlorine gas and sand(to prevent apparatus breaking due to excess heat). A small tube through which a small piece of sodium and a drop of water is added to produce an orange flame and salt.
Potassium and water reaction
When the potassium is placed in water, it floats because it is less dense than the water. The hydrogen gas given off in the reaction pushes the potassium around on the surface of the water.
Potassium reacts violently with water. Enough heat is produced in the reaction to ignite the hydrogen gas given off. The hydrogen gas is contaminated with potassium which results in the lilac (bluish pink) flame.
Sodium and water reaction
Sodium and water also react vigorously. Sodium has a low melting point so the heat given off in the reaction is enough to melt the sodium and cause it to form a ball. As hydrogen is produced, it pushes the ball of sodium around on the surface of the water. Sometimes, the hydrogen can ignite and produce an orange flame due to the sodium impurities it contains.
Lithium and water reaction
When lithium reacts with water it does not produce heat quickly enough to ignite the hydrogen given off or melt the lithium, which has a higher melting point than potassium and sodium. (Colourless)
Calcium and water reaction
The calcium metal begins to bubble vigorously as it reacts with the water, producing hydrogen gas, and a cloudy white precipitate of calcium hydroxide.
Magnesium and water reaction
It is possible to create a weak reaction between very clean magnesium ribbon and cold water. However, it is likely to only result in a few bubbles of hydrogen gas as the magnesium hydroxide produced is insoluble and forms a barrier on the surface of the magnesium. This barrier prevents further reaction.
Potassium, Calcium, Sodium or Lithium reaction with steam.
If reacted potassium, sodium, lithium or calcium with steam, the resulting reaction would be so violent that the metal would explode, igniting the hydrogen in a fiery ball.
Can metals below magnesium in the reactivity series reacted with water at room temperature?
No, it requires extra energy in form of heat to react.
Reaction of metals with acids.
Group 1 metals (potassium, sodium and lithium) react violently even with dilute acids. The reaction will often produce enough heat to ignite the hydrogen gas given off.
Other metals produce less violent reactions with acids. The speed of these reactions and quantity of hydrogen produced can be used to arrange the metals in order of their reactivity, with aluminium being a notable exception.
Reaction observations of aluminum and acid.
The initial reaction seems very slow, but visibly speeds up later on.
Flame colour in Potassium salt + Oxygen, product colour
Light-purple colour. Potassium oxide is light-yellow coloured.
Flame colour in Sodium salt + Oxygen, product colour
Bright-yellow flame, Sodium oxide is white coloured.
Flame colour in Lithium salt + Oxygen, product colour
Red coloured flame, Lithium oxide is white coloured.
Flame colour in Calcium salt + Oxygen
Intense orange colour
Flame colour in Magnesium salt+ Oxygen
Exceptionally bright white flame, requires sunglasses or welding glasses as protection for eyes.
Flame colour in Aluminium salt+ Oxygen, product properties
Bright white flame, less bright than magnesium+oxygen flame. Product is white and insoluble in water.
Flame colour in Zinc salt+ Oxygen, product properties
Light blue flame, white product insoluble in water.
Flame colour in Iron + Oxygen, product properties
When iron burns it produces a bright orange flame. The iron (III) oxide produced has an orangey brown colour, while tri-iron tetroxide is dark grey or black. Iron oxide is insoluble in water.