Download 8.1 – Viscosity and the effects of temperature

8.1 – Viscosity and the effects of temperature 1) Write a short paragraph to describe viscosity. Include at least 2 examples of fluids and the words “flow”, “fluid”, “particles” and “viscosity”. The Viscosity of a fluid affects the flow of a liquid. If a liquid flows at a slower rate it’s because it has a high viscosity. It means that the particles of the liquid are closer together and take more time to move. 2) Draw a diagram to show what happens to the particles when a liquid is heated. The distance between the particles will increase and the forces of attraction between the particles decreases as well after heating. 3) Draw a diagram to show what happens to the particles when a gas is heated. The particles in the gas will move faster when heated and collide more often causing more friction. 4) You are making cookies that call for 3 tablespoons of molasses, but you are having trouble measuring out the thick syrupy liquid. What could you do to make it easier to pour and measure this fluid? You could warm the molasses in a warm water bath to decrease its viscosity 5) Describe 2 substances that are useful because of their viscosity. Motor Oil is useful for lubricating moving parts in a bicycle. 6) You are given 3 samples of the same shampoo at three different temperatures: 35 degrees Celsius, 50 degrees Celsius and 75 degrees Celsius a) Which sample has the highest viscosity? The sample at 35 degrees b) Which sample has the highest flow rate? The sample at 75 degrees c) Which sample has the highest density? The sample at 35 degrees 7) In a fair test, you should change only one variable so that you can see the effects of the variable you changed. Suppose you were investigating the flow rates of various liquids by measuring the time that each took to flow down a ramp a) which variable would you change during the test? Try different liquids b) What variables would you keep the same? The steepness of the ramp, The temperature of the liquids, the ramp distance. 8.2 – Density and Volume 1) In which state of matter is a substance : Least Dense: ____Gas_______________________________________________ 2) Explain how density causes a substance to: Sink: The object/substance has a greater density than the fluid it is placed in Float: The object/substance has a lesser density than the fluid it is placed in Hover: The object/substance has about the same density than the fluid it is placed in 3) What is the relationship of temperature to density? As the temperature increases in most substances the density decreases 4) The table below shows mass and volume data for mineral oil. Mass (g) Volume (mL) 0.8 1.0 1.6 2.0 2.4 3.0 3.2 4.0 a) What happens to the mass of the mineral oil as the volume changes As the volume increases the mass increases b) What is the density of mineral oil? Density = Mass ÷ volume = 0.8g ÷ 1.0mL =0.8g/ml c) What happens to the density as the mass and volume change? The density remains the same 5) Draw a diagram below to help explain how a heavy ship can float on water A heavy ship can float on water if the density of the ship is less than the body of water that surrounds the ship. What is the density of each of the following substances? a) 2.0 mL of mercury with a mass of 27.1g D = 13.55g/mL b) 0.5mL of silver with a mass of 5.25g D= 10.5g/mL c) 2.5 mL of lead with a mass of 28.5g D=11.4g/mL 8) If you had 100mL of each substance in question 7, which one would have the greatest mass? Mass = density x volume. Therefore the substance with the greatest density will have the greatest mass. Mercury D=13.55g/mL would have a mass of 1355g.