The mass of an empty container at 28 o C is 83.93 g. The mass of the container when filled with water from a 25-mL pipet is 108.70 g. Calculate the true volume of delivered water by the calibrated pipet.

The mass of an empty container at 28 degrees Celsius is 83.93 grams. The mass of container when filled with water from a 25 milliliter pipette is a 108.70 grams. Calculate the true mass of delivered water by the calibrated pipette. Here, we're talking about determining the volume of our pipette. Basically, we have to rely on the table that we see on the previous page in which we have the 2 columns. Remember, we have the volume delivered by the water at the given temperature and then we have the volume when corrected to 20 degrees Celsius. In this example, we'll do both so we can see what the difference in volume delivered by the pipette. Now here we have an empty container and when it's empty, it's 83.93 grams. We're gonna fill it up with water When we fill it up with water from our pipette so I'm not good at shading inside the lines. But we know when we fill it up with water, it's now a 108.70 grams. So the amount of water delivered in terms of mass would be a 108.70 grams minus 83.93 grams. So it gives me 24.77 grams of water that's been delivered. Now, at 28 degrees Celsius, we're told that for every 1 gram of water, the amount of delivered water would be 1 point 0048 milliliters of water. Again, we're getting this number from the chart on the previous page. So we take that 24.77 grams of water. We multiply it by this ratio here, so 1.0048 milliliters of water for every 1 gram of water. Here, initially, we'd say we have 24.8889 milliliters of water that's been delivered at that temperature. Remember, when it comes to our glassware, it's traditionally calibrated at 20 degrees Celsius. Because of that, the actual amount of volume of water delivered would be so this is at 20 degrees Celsius with our calibrated pipette. So we have 24.77 grams of water. Now based on our chart, after it's been corrected, it'll be 1 gram of water delivers 1.00 47 milliliters of water delivered. So here, in actuality, it's 24.8864 milliliters of water that's been delivered by my 25 milliliter pipette. So again, remember, thermal expansion. We have to minimize all outside factors to get as accurate and precise of values as we can. This is incredibly important when it comes to getting the correct volume. One of the first things you do in analytical lab is you're gonna calibrate your pipettes. And if you do not calibrate them correctly, you'll get an improper value improper volume and that compounds itself as you do more experiments in labs this semester. And so compounds itself as you do more experiments in labs this semester. It's gonna be important that you guys are able to ascertain the exact volume as closely as possible. If you don't, that could ruin calibrations when it comes to determining the mass of an unknown, the molarity of an unknown when it comes to titration reactions later on this semester. So again, thermal expansion takes into account that changes in temperature have a direct impact on the density and volume of water and solutions.