Chemistry: Mixtures and Compounds

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the smallest part of an element that can exist?

Atom

What is a molecule?

A molecule is made of a fixed number of atoms, which are covalently bonded together.

Which of the following is NOT a type of atom?

Atom

Neutron

Electron

Proton (correct)

What is the name given to tiny particles which make up elements?

Atoms Signup and view all the answers

What are elements?

An element is made of one type of atom. Signup and view all the answers

What are elements arranged by in the periodic table?

Atomic number Signup and view all the answers

What is a compound?

A compound is a substance that contains two or more elements chemically combined together. Signup and view all the answers

What are the smallest particles with a positive charge?

Protons Signup and view all the answers

What is a nuclear model?

The nuclear model is a model of the atom in which there are electrons that orbit the central positively charged nucleus. Signup and view all the answers

According to the plum pudding model, what is the atom composed of?

A positively charged sphere with negatively charged electrons randomly embedded within it. Signup and view all the answers

The majority of the mass of an element is in the nucleus.

True Signup and view all the answers

What is a key difference between Rutherford's nuclear model and Thompson's plum pudding model?

Rutherford's nuclear model has a positive nucleus and electrons orbiting around it, while Thompson's plum pudding model had a positively charged sphere with electrons scattered throughout. Signup and view all the answers

What is the atomic number of an element?

The atomic number of an element is the number of protons in the nucleus of an atom. Signup and view all the answers

What does the relative atomic mass (Ar) represent?

The average mass of atoms of an element relative to the mass of an atom of carbon-12. Signup and view all the answers

What is the difference between isotopes of the same element?

Different number of neutrons Signup and view all the answers

What are the highly reactive metals in groups 1 and 2 of the periodic table known as?

Reactive metals Signup and view all the answers

What are the elements in group 0 of the periodic table also known as?

Noble gases Signup and view all the answers

What is the process of separating a solvent from a solution by heating it, collecting the vapor, and then cooling it to form liquid?

Distillation Signup and view all the answers

What is fractional distillation used to separate?

Mixture of different liquids Signup and view all the answers

Which technique separates a soluble substance from a solvent by forming crystals?

Crystallisation Signup and view all the answers

What is paper chromatography used to separate?

Mixtures of soluble substances in a solution Signup and view all the answers

What is the process of separating a mixture by passing it through a filter paper?

Filtration Signup and view all the answers

What does a compound involve that makes it different from a mixture?

Chemical bonding Signup and view all the answers

Study Notes

Mixtures and Compounds

Mixtures are made of two or more elements or compounds mixed together without chemical bonds.
The chemical properties of each substance in a mixture do not change.
Mixtures can be separated by physical processes, such as filtration, crystallisation and distillation.
Mixtures can include solids, liquids, or gases.

Compounds

Compounds are formed from two or more elements bonded together chemically.
Compounds have different chemical properties from the elements they are made of.
Compounds can be separated by chemical reactions.

Separating Mixtures

Substances in a mixture can be separated by physical processes.
Filtration can separate an insoluble solid from a liquid.
Crystallisation is used to separate a dissolved solid from a liquid solvent. Process involves evaporating the solvent and cooling, forming crystals.
Distillation, can be used to separate a liquid solvent from a solution by heating the mixture and collecting the vapour that condenses.
Fractional distillation is used to separate liquids from a mixture of miscible liquids, which have different boiling points.

Waste Water Treatment

Large objects are removed (branches and leaves).
Insoluble particles are removed (coarse filter bed)
Smaller insoluble particles are removed (fine filter)
Harmful microorganisms are removed (chlorine gas).
Water becomes potable.

Seawater Treatment

Seawater can be made drinkable by distillation.
Seawater boils, and the water vapor is cooled, forming pure water.

Distillation

Distillation is used to separate a solvent from a solution.
Set up apparatus with round-bottomed flask, heat source, thermometer, condenser, and collecting beaker.
Heat the solution until the liquid evaporates to vapour.
Cool the vapor in the condenser to turn it back into a liquid and collect it in a separate beaker.
The solute remains in the original flask.
The boiling point of the solute is higher than the solvent.

Fractional Distillation

Used to separate liquids with different boiling points in a mixture.
A fractionating column (long tube with glass beads) is used.
The mixture is heated. The liquid with the lowest boiling point evaporates first and rises through the column.
The vapours condense at different points on the column, depending on their boiling points.
The liquids are collected at different points in the column.

Filtration

Separates an insoluble solid from a liquid.
Pour the mixture into a filter funnel with filter paper.
The insoluble solid (residue) is retained on the filter paper.
The liquid (filtrate) passes through the filter paper.

Crystallisation

Separates a soluble solid from a solution.
Heat the solution to evaporate some or all of the solvent, concentrating the solution.
Slowly cool the solution to allow the dissolved solid to form crystals.
Crystals are separated by filtration.

Paper Chromatography

Separates mixtures of soluble substances based on their differing solubility in a solvent.
A mixture is dissolved in a solvent.
A small amount of the mixture is placed on a piece of chromatography paper.
The paper is placed in a suitable solvent.
The solvent moves up the paper, carrying the different substances at varying speeds, depending on their solubility.
The separated substances are seen as different colored spots on the paper.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the fundamental differences between mixtures and compounds, including their properties and methods for separation. Understand the physical processes involved in separating mixtures and how compounds are formed. Test your knowledge to master these key concepts of chemistry.