9F — Reactivity Flashcards
What are the properties of physical changes?
— Do not make new substances.
— Are often easy to reverse.
— The substances may change state or just be mixed together.
— Examples include: melting, boiling, condensing, freezing.
What are the properties of chemical reactions?
— Always make one or more new substances. Are usually difficult to reverse.
— The new substances have different properties from the original substances.
— Examples include: combustion, neutralisation, thermal decomposition.
What is gas pressure?
Gas pressure is caused by the force of the particles hitting the walls of the container.
What is the reactivity series?
The reactivity series is a list of metals in order of reactivity, with the most reactive at the top.
How can rusting be prevented?
● a physical barrier to stop the air and water being in contact with the iron
● sacrificial protection, in which blocks of a more reactive metal, such as zinc or magnesium, are attached to the iron. They then corrode instead of the iron.
1) What is steel?
2) What is needed for iron to rust?
3) How can rusting be sped up?
1) Steel is an alloy containing iron mixed with small amounts of carbon and sometimes other metals.
2) Iron needs air and water to rust.
3) Rusting can be sped up with salt.
1) What is an exothermic reaction?
2) What is an endothermic reaction?
1) Exothermic reactions transfer energy from the reactants to the surroundings. The temperature of the surroundings increases.
2) Endothermic reactions use energy transferred from the surroundings to the reactants. The temperature of the surroundings decreases.
What is a displacement reaction?
In a displacement reaction, a more reactive metal takes the place of a less reactive metal in a compound.
1) How are metals from zinc downwards extracted from their ores?
2) How are metals above zinc extracted from their ores?
1) Metals from zinc downwards in the reactivity series can be extracted from their ores by heating with carbon.
2) Metals above zinc in the reactivity series need electrolysis to extract them from their ores.
1) Is reduction the gain or loss of oxygen?
2) Is oxidation the gain of loss of oxygen?
1) Reduction is the loss of oxygen.
2) Oxidation is the gain of oxygen.
What is the formula for percentage loss or gain?
Actual change/ Original amount x 100
What is the reactivity series acronym?
Please — Potassium Stop — Sodium Calling — Calcium Me — Magnesium A — Aluminium Careless — (Carbon) Zebra — Zinc Instead — Iron Try — Tin Learning — Lead How — (Hydrogen) Copper — Copper Saves — Silver Gold — Gold
