Chemistry Flashcards
A bee sting contains acids. Explain why some people use an alkali such as baking soda on bee stings.
You do this because adding an alkali will neutralize the acidity of the bee sting.
What is the difference between corrosion and rusting?
Corrosion refers to any reaction with oxygen at the surface of a metal. Rusting refers to the corrosion of iron.
What is the word equation for the corrosion of tin and the rusting of metal.
Tin + Oxygen = Tin oxide
What is an atom?
Small particles from which all substances are made of
What is an element ?
A simple substance made up of only one type of atom.
What is a compound?
A substance that can be split up because of the 2 or more elements formed together.
What is a mixture?
Two or more substances jumbled together but not joined to each other. The substances can often be separated.
Why are alloy often stronger than pure metals?
Alloys are made up of atoms of different sizes instead of being uniform. This means that the layers of atoms cannot slide over each other easily, making the whole alloy much stronger than any of the pure metals that the the alloy contains.
What is an exothermic reaction?
A reaction in which energy stored in the reactants is transferred to the surroundings.
What is an endothermic reaction?
A reaction in which energy is transferred to the surroundings to the reactants.
What does thermal decomposition mean?
Thermal decomposition is a chemical reaction where heat is a reactant. Since heat is a reactant, these reactions are endothermic meaning that the reaction requires thermal energy to break the chemical bonds in the molecule.
Describe the Bunsen flame colours and what each flame is used for
Quiet yellow flame- a safety flame which is not used because it leaves a layer of soot on surfaces.
Medium blue flame- used for heating
Noisy blue flame or roaring flame - used for heating quickly
What are some properties of metals?
Malleable, Shiny, Good conductor, Not brittle
What are some properties of non metals
Brittle, dull, poor conductor of heat and electricity
What is the Law of conservation of mass?
Energy cannot be created or destroyed
Describe a method to show how you would obtain a pure sample of salt from rock salt
- Fold a circular filter paper in half
- Fold the filter paper in half again to form a triangular shape
- Open out one layer of the paper to form a cone
- Place the filter paper cone in a filter funnel
- Place the funnel in the neck of a conical flask
- Stir the sand and water mixture so that all the sand is suspended in the water
- Pour the sand and water mixture into the filter paper
What is an independent variable?
It is a variable that stands alone and isn’t changed by other variables
What is a dependent variable?
A dependent variable is what changes as a result of the independent variable manipulation in experiments
What is a control variable?
A control variable is any variable that’s held constant in a research study. It’s not a variable of interest in the study, but it’s controlled because it could influence the outcomes.
Why is a pencil line used in chromatography?
Because it does not dissolve in the solvent and affect the results.
What is suspension?
A mixture of a solid or a liquid, where the solid bits are heavy enough to settle out if the mixture is left to stand
What is a solvent?
A liquid in which a substance dissolves to make a solution
What is a solute?
The substance that has dissolved in a liquid to make a solution
What is a solution?
When a substance has dissolved into a liquid.
