IGCSE Coordinate Science 1 Particle Movement and Rates of Reactions P04, C7.1, B03 Key Notes

Review List the three major states of matter & brainstorm everything you can remember about each one.

States of Matter Solids – occupies a fixed volume and has a fixed shape.

States of Matter Liquids – occupies a fixed volume but takes the shape of its container.

States of Matter Gasses – expands to fill its container and takes the shape of its container.

What can you say about the distances between molecules of solids, liquids and gasses? What can you say about the forces between molecules of solids, liquids, and gasses?

Temperature – the measure of the average kinetic energy (KE)of all the particles in an object. (KE refers to energy due to motion) Pressure – amount of force per unit area. Volume – amount of space occupied by an object.

Simulation Based on the simulation, what can you say about the relationship between: – Temperature of a gas vs. motion of its molecules? Increase in temperature will increase the motion of its molecules. – Pressure of a gas vs. motion of its molecules? When the number of molecules and the volume of the container is kept constant, increasing the temperature will increase the motion of the molecules thus increasing pressure (increasing the chances for the molecules to hit the walls of the container) – The effect of a change in temperature to the pressure of the gas at constant volume? When the number of molecules and the volume of the container is kept constant, increasing the temperature will increase the motion of the molecules, thus increasing pressure (increasing the chances for the molecules to hit the walls of the container)

Boyle’s Law The volume of a fixed mass of gas is inversely proportional to its pressure, provided its temperature remains constant. p 1 V 1 = p 2 V 2 initial pressure x initial volume = final pressure x final volume ( pV = constant )

Example A cylinder contains 50cm 3 of air at a pressure of 120 kPa. What will its volume be if the pressure on it is increased to 400 kPa?

Evaporation Evaporation is not boiling. It is the escape of more energetic molecules from the surface of a liquid

Factors affecting evaporation Temperature: Surface area: Air flow over a surface:

Explain this statement: Evaporation is a cooling process.

IN Write a few sentences explaining how temperature, pressure, and motion of molecules in a container of fixed volume are related.

Chemistry (C7.1)

Reaction Rates Labs Follow the directions carefully for the lab. You may have more than one time trial going on at one time as long as you have enough timing devices! Thoroughly clean your test tubes, baby beakers, and measuring cylinders well between labs so you don’t contaminate your next set of chemicals.

Rates of Reaction Explain the concept of “rate” Influenced by: – Temperature – Concentration – Surface area – Catalysts Explain each of these at the particle level using this simulation: s-and-rates s-and-rates

Explosions! Read pg. 136 – 137 and answer Q3 on pg. 137

Experimental Design Adding magnesium to hydrochloric acid (HCl) produces hydrogen gas. – If you were to repeat this experiment, how could you collect quantitative (numerical) data on the rate of reaction? Devise a method for data collection. Available materials include: test tubes, beakers, syringe, tubing, stopper with holes in them, measuring cylinders, pipets, HCl, magnesium, markers, rulers, stopwatches

Methods for Calculating Rate of Gas Production: Collecting Gas in a Syringe

Methods for Calculating Rate of Gas Production: Collecting Gas over Water Graduated Cylinder for measuring volume of gas produced

Biology (B03)

Catalysts Catalysts: An agent which increases the reaction rate but which itself remains unchanged. Enzymes: Proteins that function as biological catalysts.

Enzymes Enzyme Active Site Enzyme -substrate complex 2 1.Substrates bind to enzyme 2.Substrates are converted into products 3.Products are released

Enzyme videos hill.com/sites/ /student_view0/ch apter2/animation__how_enzymes_work.html hill.com/sites/ /student_view0/ch apter2/animation__how_enzymes_work.html 2.htm 2.htm

Regulating Enzymes Denatured: When an enzyme loses its 3D shape, so the active site can no longer bind to the substrate. Enzyme activity is affected by: – Temperature 37 o C is usually optimal for enzymes in humans. Why? – pH

Your aim is to be able not just to recreate the graphs, but to annotate and explain their shape in terms of what is happening at a molecular level.

Catalase Lab You must wear lab safety goggles, apron, and gloves the whole time. Do Investigation 1, and then finish either Investigation 2 or 3 today.