Substance Review PDF
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Summary
This document reviews the different types of matter, including pure substances (elements and compounds) and mixtures. It explains the properties and characteristics of solids, liquids, and gases, based on the particle theory. The document also briefly touches on concepts concerning heterogeneous/homogeneous mixtures.
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atter M Matter is anything that has mass and takes up space. All matter can be classified as either a pure substance or a mixture. All matter is made up of tiny particles. The study of matter and its changes is called chemistry. The Particle Theory Matter can be...
atter M Matter is anything that has mass and takes up space. All matter can be classified as either a pure substance or a mixture. All matter is made up of tiny particles. The study of matter and its changes is called chemistry. The Particle Theory Matter can be classified according to its physical characteristics. The particle theory of matter helps to explain the physical characteristics of matter. verything is made of particles E There are spaces between the particles Particles are attracted to each other Gas Temperature affects the speed at which particles move Particles are always moving because they have kinetic energy here are different kinds of particles. but all particles of one substance are T identical Solids In solid form particles are close together. The particles are very strongly attracted to each other. They are locked in a pattern and vibrate in place. Solids have a fixed shape and volume. The spaces between the particles are small. iquids L In liquid form, particles are slightly farther apart. Particles are less attracted to each other and are able to slide past each other. The spaces between the particles are larger than in a solid. as G In gas form. particles are far apart and can move in any direction because the attraction forces between them are weak. Gases have no fixed shape and no fixed volume. They expand to fill their container. Particle Theory he particle theory states that all matter is made up of tiny particles that are T constantly moving. The speed the particles move depends on which state of matter they are in. Solids Particles in solids are held tightly together They are strongly attracted to each other. meaning they move slowly. These particles vibrate instead of move. but they are not still. Liquids Particles in liquids are fairly close together with some attraction between them. They move around in all directions. but they can't move too far because they are attracted to the particles near them. Gases Particles in gases have hardly any attraction between them. They move rapidly in all directions. They collide with each other and the walls of the container they are in. toms vs Molecules A Atoms are the smallest particles. They cannot be divided further, and they are the building blocks of matter Elements are either single atoms or two or more of the same type of TOM A 8 PROTONS toms bonded together For example, a hydrogen is an element that is made of two hydrogen atoms. NEUTRONS 8 ELECTRONS 8 OXYGEN OLECULE M OXYGEN ATOM HYDROGEN ATOMS a WATER H20 A molecule is a group of atoms bonded together Therefore. hydrogen is a molecule because it is made of two hydrogen atoms. In fact. hydrogen is the smallest molecule! A compound is a molecule as well because compounds have more than two atoms bonded together. However. the key difference between an element and a compound is that compounds are made of two or more different elements that are combined. Water is a compound because it is made of two different elements (hydrogen and oxygen) that are bonded together Water has two hydrogen atoms combined with one oxygen atom. Pure Substances All matter is either a pure substance Elements, Compounds and mixtures r a mixture. A pure substance is made of just one element or one compound. o while a mixture has more than one element or compound. Hydrogen is a molecule that is a pure substance because it is made of just one element. Water is a pure substance because it is made of just one compound. Other examples of pure substances are sugar. table salt. baking soda. aluminum and gold. Mixtures 11 atter is most often a mixture. A mixture M contains two or more types of elements or compounds. In a mixture. no chemical reaction takes place between the particles. The different elements or compounds do not C2.2. C2.3 CLASSIFYING MATTER MATTER URE P SUBSTANCE ond together chemically. b Mixtures come in different proportions and they don't have a fixed ratio. When you mix your cereal with milk. you are making a mixture and you are in control of how much milk you add compared to the cereal. The milk and cereal have separate elements and compounds. Mixtures can be separated by physical means. You can strain the milk from the cereal easily. Mixtures can be homogenous mixtures or heterogenous mixtures. The difference between the two types of mixtures is how well they are combined. Heterogenous Mixtures Heterogenous mixtures are made up of two or more types of particles. You can see or feel the different types of particles. For example. cereal in milk as well as oil and water. eterogenous mixtures are not uniform. If you take a sample from different parts H of the mixture. the sample will not have the same composition. You can separate components of a heterogenous mixture. For example, you can pick the cereal out of the milk, or you can allow the oil to float to the top of the water and skim it off. Homogenous Mixtures Homogenous mixtures are made of two or more types of particles but look like only one type of particle. For example. apple juice, sugar and water, blood, and sports drinks. atter can be classified by its state: solid. liquid or gas. Matter can also be M classified into two categories: pure substances or mixtures. When you look at a teaspoon full of sugar you can see that all the parts are the same. Sugar is a pure substance. In pure substances there is only one kind of particle (one kind of element or compound). Every part of the substance has the same composition as every other part. Mixtures are made of two or more substances. In some mixtures like pizza, we can see the different ingredients and easily separate the pepperoni from the pizza. In other mixtures, such as soft drinks. you cannot see the individual parts. You can taste the sugar. but you cannot see it separately as it is a homogenous mixture. eterogenous vs Homogenous Mixtures H A homogenous mixture is uniform. meaning the matter looks the same throughout. Steel, air. rain. and wine are all homogenous mixtures because they look the same throughout and they are made of more than one type of particle. If you took part of the mixture out. it would be the same as the rest of the mixture. This is because the particles are arranged in an organized way where they blend together A heterogenous mixture is different. It is not-uniform, meaning the particles are not organized. Instead. the particles can be arranged in any random way. Mixtures 16 ixtures are made of two or more substances that are not M chemically combined. They are combined physically and the substances combined together retain their original chemical identity. Mixtures can be in the form of solids. liquids. and/or gases. in any combination. n example of a liquid mixture is vinegar and water. These will form a A homogenous mixture because you will not be able to see the individual components. Two solids. salt and sand will form a heterogenous mixture. You will be able to see each component even after you mix them together. Brass is a solid homogenous mixture of copper and zinc. Soft drinks are a mixture of all three states of matter. A liquid. water. is mixed with a solid, sugar and flavouring that could be solid or liquid. These ingredients are mixed with carbon dioxide, a gas, to give the drink bubbles. Air is a mixture of gases including nitrogen, carbon dioxide and oxygen. Mechanical Mixtures ixtures can be classified as mechanical mixtures or solutions. M Mechanical mixtures are heterogenous mixtures. You can see the components after you have combined the components. When you make a salad. you combine the ingredients, but you can still see them separately and they maintain their own properties. The oil and vinegar salad dressing you use on your salad is also a heterogenous or mechanical mixture because the components don't mix, they maintain their own properties. Another example of a mechanical mixture is asphalt. The components. gravel. sand and bitumen form together and make a strong solid road surface. however. you can still see the individual components of the asphalt. Solutions SOLUBILITY solution is a homogenous mixture. Therefore, a solution A looks like a single pure substance. It is a uniform mixture of two or more pure substances. There are two main parts of a solution. 1. A solute which is the substance that is being dissolved into the other substance. The solute is the Solute smaller part of a solution. Salt is a solute because it dissolves into water. Solvent Solution 2. A solvent which is the substance that dissolves the other substance. The solvent is the larger part of the solution. the part of the solution into which the solute dissolves. How Do Solutions Form? When particles of one substance are more attracted to particles of another substance than they are to themselves, they will form a solution. Particles on the surface of the solute will break away and begin to fill the spaces between the solvent particles until all the solute particles are evenly mixed between the solvent particles. The process of a solute mixing with a solvent is known as dissolving. Not all substances dissolve in other substances. For example, sand and water are two separate substances that will not form a solution because the sand will not dissolve in the water. Water and Water Pollution Water dissolves more different substances than any other solvent. Because water is the most common solvent in solutions it is called the universal solvent. Water does not dissolve everything. Oils and fats are not water soluble. Our bodies are 70 percent water. The water in our bodies is a solvent that can carry calcium, potassium, oxygen and salt to name a few of the essential nutrients our bodies need to function. Blood is a solution made of the water (solvent), salt (solute). and proteins (solute). Seventy percent of the earth's surface is covered by water. Solutes in the water can be absorbed by plants and living things. Fertilizer. pesticides. waste from mining, sewage and household products put down the drain are all solutes that can be dissolved in water causing water pollution. Solid Solutions Solutions that are solids have both solid solutes and solid solvents. Pure gold is 24 Karat gold. It is a pure substance. 14 Karat gold has 14 parts gold to 10 parts other metals. To make a solution both metals are heated and mixed together into a homogenous mixture. Gold is the solvent and the other metals are the solutes. niversal Solvent — Water U Water is called the universal solvent because more substances dissolve in water than in any other substance. This is important because as water moves, it is breaking down and carrying valuable chemicals, minerals. and nutrients. Water is the best solvent because of its chemical composition. Water molecules are each made of two hydrogen atoms and one oxygen ow Does Salt Dissolve in Water H Salt Crystal Water Molecule Salt Molecule he Na+ atoms attract negative T oxygen atoms. The Cl- atoms attract positive hydrogen atoms atom. This gives them a positive electrical charge on their hydrogen side and a negative electrical charge on their oxygen side. Since opposite charges attract. water molecules can attract many other different types of molecules as it has both charges. Saltwater — Dissolving Salt in Water Water is so heavily attracted to other substances. like salt. that it will break it down and dissolve the other substance. changing its chemical composition. When salt is added to water, the salt molecule made of one sodium and one chlorine atom are separated. This means the single atoms are floating by themselves in the water. The positive sodium atoms from the salt attracts the negative oxygen atoms from the water and the negative chlorine atoms from the salt attract the positive hydrogen atoms in the water The attraction is strong. creating new saltwater molecules that are bonded together. forming a homogenous solution. Insoluble Substances Some substances. like oil. will not dissolve in water. These insoluble substances have atoms that are very strongly attracted or bonded to each other Therefore, the water molecules cannot separate them. so we will see both the water and oil molecules. actors Affecting Solubility F Solubility is a term used to describe how well a solute will dissolve into a solvent. Sand has no solubility in water but salt is soluble in water. There are a few factors that impact the solubility of a solute. 1) Concentration The concentration of a solution is how much solute there is compared to the amount of solvent. When you mix hot chocolate powder with water. the more solute (chocolate powder) you add to the solvent (water or milk). the stronger the concentration. You can dilute solution by adding more solvent. The higher the concentration. the less soluble the solute becomes. This is because there is a limit to how much solute that can be dissolved into the solvent. Picture trying to dissolve a large spoonful of hot chocolate powder into a small amount of water. You will likely see clumps as the powder won't dissolve to make the solution. 2) Temperature The temperature of the solvent is also a factor. Usually when we heat up a solvent. it can dissolve more solid materials (sugar) and less gas (carbon dioxide). The higher the temperature of the solvent, the faster the particles of the solvent move. More movement of the solvent particles causes more collisions between particles causing the solute to break down faster. hen the temperature of the solvent increases. the spaces between the solvent W particles get bigger. This leaves more room for solute particles. 3) Pressure Pressure can also affect solutions. We see this with soda as we can dissolve more gas under higher pressure. A can of soda has water (solvent) and carbon dioxide (solute) in a pressurized can to allow more carbon dioxide to dissolve into the solvent. This gives our soda more fizz. 4) Size The size of the solute particles affects the dissolving process. If you take a teaspoon of sugar and stir it into water, it will dissolve quickly. If you take a sugar cube and stir it into water. it will take longer to dissolve. This is because the solvent can only dissolve the outside surface of the solute. In the sugar cube, the outside surface protects the sugar inside from being dissolved. With a powder. the solvent can dissolve each individual grain of sugar all at oncentration C We can describe a solution in two ways — (1) with words and (2) with numbers. When we use words, we refer to the solution's concentration levels. A concentrated solution is a solution that contains a large amount of dissolved solute and very little solvent. For example. frozen juice concentrate is a concentrated solution of orange juice solids (solute) and a small amount of water (solvent). High concentration ow concentration L We also use the term dilute to describe the process of making a solution less concentrated. When we make the orange juice, we add 3 cans of water to the frozen concentrate to make delicious juice. If we add cans of water. we are diluting the orange juice and the flavour is weaker because the solution is diluted. Describing Solubility Using Numbers The amount of solute in a solvent also can be stated in quantitative terms. For Strong Concentration Weak Concentration example. if 5 grams of sugar are dissolved in 500 ml of water, the concentration of the solution is 5g/500ml or lg/100ml. This can be read as, five grams per five hundred millilitres. or one gram per one hundred millilitres. We could also call this a 1% solution. When making hot chocolate. the instructions state to add 50 grams of powder to one cup (250ml) of water or milk. The ratio is 50g/250ml. This would be 20% solution. To make a more concentrated solution. you could double the amount of powder and use a ratio of 100g/250ml. This would be a 40% solution that would taste very chocolatey. If you like your hot chocolate not too sweet. you could dilute the solution by using a ratio of 25g/250ml. The percentage of the solution would be 10% solute to solvent. inetic Energy Particles move because they have kinetic energy. Kinetic energy K is the energy of movement. The opposite of kinetic energy is potential energy. which is energy that is not in motion. Anything that is moving has kinetic energy. When a ball rolls down a hill, it has kinetic energy. When the ball rests at the top of the hill. the ball has potential energy. The particles that matter is made up of have kinetic energy. In solids. the particles vibrate in one place. but they do not move very much. When a substance is in a liquid state. its particles move more nd have more kinetic energy than when it is in a solid state. In a gaseous state, a the particles move the fastest because they have more room to bounce off each other. Therefore. the particles in a gas have more kinetic energy. How Temperature Affects Kinetic Energy Temperature is the measure of the average kinetic energy of the particles in a substance. It measures how hot a substance is. The higher the temperature of a substance. the more kinetic energy it will have. The particles in a warmer substance will move faster than a colder substance. This can be observed when you pour cold oil into a hot frying pan. At first. the oil will not move around the pan very quickly. As the oil heats up, it will travel around the pan much faster The oil now has more kinetic energy — more heat! Heat is the energy that transfers from a substance at a higher temperature to one at a lower temperature. You can feel heat transfer when you put a spoon into a cup of hot chocolate. Heat from the hot chocolate causes the particles in the spoon to vibrate faster. making the spoon get hotter. The particles in the spoon move faster causing the entire spoon to get hotter. not just the part of the spoon submerged in the hot chocolate. hat is Carbon Dioxide? Cl.l Carbon dioxide is a colourless gas that has a sharp W odor and a slightly sour taste. Carbon dioxide makes up 0.03 percent of the air in our atmosphere. It is a very important gas that plants need in order to produce the food they need to survive. Producing Carbon Dioxide Carbon dioxide can be produced in a number of different ways. It is emitted when carbon-containing materials such as gasoline. are burned with plenty of oxygen in and above the fire. This happens when we burn fuel in our vehicles. 150 You can also produce carbon dioxide by mixing solids and liquids. For example. mixing baking soda and vinegar together will produce a chemical reaction that produces carbon dioxide gas into the atmosphere. You may have witnessed this when building a volcano experiment and mixing the two substances to represent the erupting volcano. Carbon Dioxide Solutions When we create a solution using carbon dioxide and water. the solution is called carbonic acid. Carbonic acid is used in soft drinks to give carbonation and fizz to the drink. When you open the soft drink. the fizz you hear is the carbon dioxide separating from the liquid into our atmosphere. Aerosol cans also use carbon dioxide. They are called chlorofluorocarbons (CFCs). The gas is used to create pressure inside the can. The liquid in the can (perfume, whipped cream. bug repellant. cleaning) is mixed with the carbon dioxide gas so that when you press the button, the gas and liquid solution is released into the atmosphere. This is why we shake aerosol cans efore we use them. CFCs are adding more carbon dioxide into our environment b and are contributing to global warming. ure Substances — Elements and Compounds Humans have benefitted from P the use of pure substances since the beginning of time. Remember that all elements and compounds are pure substances. Examples of pure substances are iron. diamond, sugar. salt. gold. and aluminum. To get these pure substances. they need to be mined and then refined. Mining k. Most pure substances are found in the ground. where they need to be mined and extracted from the Earth. Mining is either done in open pits or underground. While pure substances are needed ' to build the things we have in our lives. the process of mining harms our environment. Mining for gold is often done in open pit mines. When it rains, groundwater runs over the ground that has been disturbed by the digging activity. The groundwater picks up elements such as mercury. cadmium and lead and carries it over fields where crops are grown and into lakes and rivers. Plants and marine life absorb these poisonous elements and when people eat the fish and plants. they also ingest these poisonous elements. Refining Pure Substances Pure substances don't usually occur in their pure form in nature. so in order to obtain pure substances. people must refine the raw materials they are found in. Refining is a process used with metals to separate the desired material from the impurities surrounding them. For example. when gold is mined from the earth, it isn't found in its pure form. Instead. it is mixed with other elements. usually zinc. copper, silver. and iron. To refine the gold. it is often put into a mixture of hydrochloric acid and nitric acid. The result is the other elements separate from the gold so they can be removed. leaving 99.999% pure gold. The refining process uses acids that are bad for the environment. When an acid has been used. it becomes waste. The acid waste pollutes water. affecting our drinking water and the habitats for marine animals. Producing gold for one wedding ring generates 20 tons of waste. hat is a Suspension? A suspension is a mixture of a liquid and particles of a W solid. A mixture is considered a suspension if the particles in the liquid do not dissolve. Instead. the particles become dispersed throughout the liquid after they have been mixed. They are "suspended" in the liquid. Over time. the particles will settle at the bottom. An example of a suspension mixture would be sand and water. When we mix the sand into the water. the sand will disperse throughout the water. If you leave the sand and water mixture alone. the sand will c ventually settle to the bottom because it is denser than the water (it weighs e more). Check it out In figure A above. the liquid and the solid particles are both separate. The mixture has not been stirred yet. In figure B. the stirring has begun, and the particles are now beginning to disperse throughout the liquid. In figure C. the mixture has been completely mixed and the particles are now evenly dispersed throughout the liquid. This is a suspension mixture because if we left this mixture long enough, the particles would settle again at the bottom of the liquid, just like in figure A. Heterogenous Suspensions — Not Solutions A heterogenous suspension is not a solution because it is a mixture. The one substance has not been dissolved into the other substance. Therefore. we can easily separate the two substances using physical methods. like using a strainer. Another example would be when we mix flour with water. The flour will be suspended in the water, creating a mixture. not a solution. hat is a Colloid? A colloid is a mixture where very small particles of one W substance are evenly distributed through another substance. A colloid mixture looks like a solution because the small particles appear to dissolve into the other substance. This is not the case however. as the particles are floating or suspended in the other substance. even if you cannot see it with your eyes. A colloid is similar to a suspension except for the fact that in a colloid. the particles do not eventually settle on the bottom. The particles in a colloid will stay suspended or floating. Colloids can be mixtures of solids. liquids or gases. An example of a liquid colloid is milk. Milk has butterfat globules dispersed and suspended in water. No matter how long you leave milk. the globules will not settle. Smoke is an example of a gaseous colloid mixture as particles are suspended in the air. Check it out In figure A. the water is a colloid of tiny particles (minerals) mixed in the liquid water. In figure B. the water in the milk is mixed with the butterfat globules that are slightly larger particles than the minerals in figure A. In figure C, the mud is a colloid eeøoø øoeeo eøøøø ooo ooo 0000 mixture of water and soil. The soil particles are even larger than the butterfat globules. but they will not settle regardless of how long the mixture sits. hat is an Emulsion? An emulsion is a heterogenous mixture of two or more W liquids, where one ends up as very tiny droplets inside the other. The liquids are usually not mutually soluble. which means they do not mix completely. For example. when we add water to a bottle of cooking oil. you will notice that after some shaking and agitation, the water will Liquid 2 (oil) Liquid 1 (water) Emulsion 2.a Immiscible liquids not dissolve into the oil. Instead. it will appear as bits and C pools in the oil. When you leave the bottle for awhile. the liquid with the higher density will sink to the bottom. In oil and water. water weighs more as it has a higher density. so it will sink to the bottom. Since the oil is lighter with a lower density. it rises to the top. These two liquids are immiscible, meaning they cannot be used to create a homogenous solution. Oil and Water Emulsions Most of the emulsions contain water as one of the two liquids. For this reason. emulsions are classified into two categories: (1) oil-in-water and (2) water-in-oil. Oil-in-water emulsions mean water is the main liquid and an oil liquid is being mixed into the water Water-in-oil emulsions mean that oil is the main liquid with water being mixed into the oil. Check it out The image on the left shows how oil and water interact with each other The O/ W beaker shows the oil-in-water type of emulsion. and the W/O beaker shows the water-in-oil mixture. Both are emulsions as they do not mix well enough to resemble suspensions or colloids.
