On Thursday in our chemistry class, we had a lab about phases of matter. For our experiments, we used dry ice to show sublimation, which is the process of a solid turning into a gas without having been changed into a liquid. Our main question was, "What's going on on a molecular level when dry ice sublimates?". So for the next two hours we experimented on/with our piece of dry ice.
First thing we did was see how cold it really was, and as Andrew had shown us, it could freeze our hands within seconds, so we used different objects such as pennies and pens to see how quickly they were frozen. We also observed how it froze the table, if we slid it around the table to create a fine layer of ice, it would glide at the slightest push. When left alone the table would simply develop frostbite. Next we placed a small part of the dry ice in side a small beaker of water and observed how it sublimated into CO2 before our eyes. It was a slow process but exciting as we looked like wizards and witches with smoke billowing from our "pot". After that Andrew came along and placed a piece of dry ice roughly 2cm wide in balloons we all had. When tied and left alone (or shaken) the balloons inflated from the sublimation happening inside. Eventually the dry ice was all gone and we were left with balloons that we measured to see how much volume is taken up from a piece of solid CO2 when it converts back into a gas.
Our measurement of the balloon showed us that it had a diameter of 7cm. So based on the equation (VsolidCO2/VsolidCO2) : (VgaseousCO2/VsolidCO2), our ratio for the volume between solid and gaseous CO2, was 1 : 5.359375 . For every 1 cubic centimeter of solid CO2, when gaseous it becomes 5.359375 cubic centimeters. This was found by calculating the volume of both the solid CO2 and gaseous CO2 using the equation for solving the volume of a sphere [(4/3)pi(r^3), r being the radius]. Judging from this, we can clearly see that upon turning a solid into a gas, the space between molecules is greatly increased and forces the molecules to take up a much greater volume then they had previously.
First thing we did was see how cold it really was, and as Andrew had shown us, it could freeze our hands within seconds, so we used different objects such as pennies and pens to see how quickly they were frozen. We also observed how it froze the table, if we slid it around the table to create a fine layer of ice, it would glide at the slightest push. When left alone the table would simply develop frostbite. Next we placed a small part of the dry ice in side a small beaker of water and observed how it sublimated into CO2 before our eyes. It was a slow process but exciting as we looked like wizards and witches with smoke billowing from our "pot". After that Andrew came along and placed a piece of dry ice roughly 2cm wide in balloons we all had. When tied and left alone (or shaken) the balloons inflated from the sublimation happening inside. Eventually the dry ice was all gone and we were left with balloons that we measured to see how much volume is taken up from a piece of solid CO2 when it converts back into a gas.
Our measurement of the balloon showed us that it had a diameter of 7cm. So based on the equation (VsolidCO2/VsolidCO2) : (VgaseousCO2/VsolidCO2), our ratio for the volume between solid and gaseous CO2, was 1 : 5.359375 . For every 1 cubic centimeter of solid CO2, when gaseous it becomes 5.359375 cubic centimeters. This was found by calculating the volume of both the solid CO2 and gaseous CO2 using the equation for solving the volume of a sphere [(4/3)pi(r^3), r being the radius]. Judging from this, we can clearly see that upon turning a solid into a gas, the space between molecules is greatly increased and forces the molecules to take up a much greater volume then they had previously.