Cooling curves are used for illustration and evaluation of the quenching characteristics of a quenchant. An investigation of the errors in cooling curves and. Below is a cooling curve that shows the process of going from gas to liquid, and then back to ice cube. The part is heated and then quenched in the cooling medium. If you dont see any interesting for you, use our search form on bottom v. If not, explain how your prediction differed from the experiment. What is the freezing temperature of the above substance. Plot a graph of time versus temperature for the heating of ice. Assess your understanding of heating and cooling curves with this quiz and worksheet. They use the graph to answer eleven questions about the phases of the substance and the changes shown in the graph.
The increase in temperature causes the water to change from a solid to a liquid. The heat of fusion for water hf is 80 caloriesgram and the heat of vaporization hv for water is 540 caloriesgram. A cooling curve is obtained using a thermocouple inserted in a workpiece or test probe. Lab report for water experiment linkedin slideshare. To do well on this assessment, youll need to know about the various phases on a heatingcooling curve.
This is assisted by an experiment in real classroom conditions. Remove test tube sample from the hot water bath and place in into a test tube rack. They analyze the slope of heating and cooling curve. What is the boiling temperature of the above substance.
In this chemistry lesson, students perform a virtual experiment to determine the boiling and melting points of different substances. Fill a test tube with naphthalene until it is about a quarter full. The flat spot on the graph, at zero degrees, shows that although heat was being. The video looks closely at heating and cooling curve of water focusing on the three states of matter. The experiment described above can be summarized in a graph called a heating curve figure below. The part of the graph labeled e represents temperatures at which gas is being heated. Heat some water separately to a temperature of about 40 oc above the room temperature. Grade 10 physical science prescribed experiment cooling. A learner guide for grade 10 physical sciences with learner activities for. Record initial temperature in appropriate place on data table. For example, this is the heating curve for iron, a metal that.
The summative assessment will be the students lab report and answers to the analysis questions from the heating curve lab. An experiment combined with some simple heat transfer calculations is discussed. What would the hypothesis be for doing a heating and. If this curve is read from right to left, it is a cooling curve. They are to measure and graph the heating of water while correctly analyzing how. Rate of heating and cooling 0 100 200 300 400 35 30 25 20 t oc t sec example. Different substances have different melting points and boiling points, but the shapes of their heating curves are very similar. Electrical heating allowed us to determine the heat entering the system to a high accuracy. States of matter and the kinetic molecular theory siyavula. Nect gr 10 heating and cooling curve of water youtube. Pdf introducing specific heat through cooling curves.
A cooling curve gives the changes in temperature as we move from gasto liquid to solid. This indicates how strong in your memory this concept is. So what does the opposite of heating curve look like. As heat is steadily added to the ice block, the water molecules will begin to vibrate faster and faster as they absorb kinetic energy. Since the energy added is difficult to measure directly, we will be recording the temperature change as a function of time. Heating and cooling curve of water assuit twtgroup. Heating curve worksheet buford high school chemistry. As the time increases i predict that the temperature of the water will decrease due to the heat loss when water evaporates or the cooling affect of the water. Steam provides a large amount of power because it is vaporized water. We analysed the heating curve of water which is described in textbooks. Use the data below to plot a heating curve for water heating curve for water time temperature oc time temperature oc 0 0. Continuously stir the sample with the thermometer and make temperature readings. Place the test tube in hot water to allow the naphthalene to melt. Copy into your lab report using a ruler to make it neat and tidy.
Although we might expect the cooling curve to be the mirror image of the heating curve in figure \\pageindex3\, the cooling curve is not an identical mirror image. On this page you can read or download grade 10 physical science prescribed experiment cooling and heating curve memo in pdf format. Experiment in the first experiment we investigated the specific heat of water. This graph goes in your quantitative observations section. We can draw heatingand cooling curves for any substance. Observe the temperature of the water as the ice water is heating. Looking from left to right on the graph, there are five distinct parts to the heating curve. You are to record your temperature every minute in degrees celsius.
Measure and record the temperature of the water every 30 seconds. Siyavulas open physical sciences grade 10 textbook, chapter 3 on states of. This experiment can be discussed about specific heat, thermal. A heating curve of a substance gives the changes in temperature as wemove from a solid to a liquid to a gas. In the science world, we use heating and cooling curves to model such physical changes. I predict that as the time increases the temperature of the water will increase due to the heat expelled from the bunsen burner or other heat source and for cooling i would put. Apparatus beakers ice bunsen burner thermometer water chipa thomas maimelas insight. Heating curve of substance x 20 22 24 26 28 30 80 75 70 60 55 temp. Now the sample is ready for the cooling curve experiment.
The theoretical behaviour can be altered by changing the conditions under which the experiment is modelled. Temperature lag takes place through the protection tube, through imperfect contact between the tube and the enclosed thermocouple, and finally through the couple itself. Continue to record the temperatures until the water continues to boil for. Heating curve lab santa ana unified school district. Mattos and gaspar 1 has been descripted the laboratory experiment for studying specific heat by using newtons law of cooling. Heating curve of water the lesson is inquiry based, asking students.
We have been given a physics assignment about the heating and cooling curves of water. We had to heat ice in a hot water bath over a bunsen burner and record the time every 30 seconds until it boiled and then in a freezer the same way it was just a hypothetical experiment. A close look at a heating and a cooling curve heating. Hot water loses heat when it is left at room temperature. During the cooling, the temperature sequence is monitored by a data acquisition system.
You will use these results to plot your own heating curve for water. In the heating curve for iron, describe the phase change that occurred between points b and c on the graph. Solid ice is heated and the temperature increases until the normal freezingmelting point of zero degrees celsius is reached. Do not change the flame height once you begin the experiment. The heating curve at right shows what happens when heat is added at a constant rate to a beaker of ice. Oxidation and fine particulate have the effect of suppressing the vapor phase and increasing the maximum cooling rate. Thermometer or other temperature measuring device i. For water, this temperature is 0c because the melting point for water is 0c. What happens when you pour that cup of water into a pot on the. It asks students to interpret the graph and explains what is happening to. Oxidation, particulate, and water can have a considerable effect on the shape of the cooling curve. This heatingcooling curve worksheet is suitable for 9th 12th grade.
To construct and interpret a heating curve for water. Heating curves notice that, in general, the temperature goes up the longer the heating continues. For this heating and cooling curve worksheet, students use a given graph of a substance being heated from a solid to a liquid and then a gas over time. We are trying to find out if water takes longer time to cool down if the starting temperatures are different. What is the melting temperature of the above substance. This interactive resource shows the heating curve produced when ice is heated. Heating and cooling curves also called temperature curves.
After 1 minute measure the temperature again and record it. Preparation of a heating curve obtain enough ice from the laboratory instructor to fill a 250 ml erlenmeyer flask about halfway. A heating or cooling curve is a simple line graph that shows the phase changes a given substance undergoes. Heating and cooling curve of water physical sciences. To investigate the heating and cooling curve of water. Heating curve of water the phase transitions of water. You should look carefully at the heating curve in your textbook, page 190, chapter 6, to identify these stages.
562 685 516 826 188 610 194 14 189 290 986 448 812 998 1259 1374 1443 1149 68 494 377 849 521 937 957 1562 1173 745 1461 1415 1370 290 583 203 422 1448 327