I am helping to implement a chemistry class for some high schoolers and we have run into the problem about significant figures in the number 0. As in 0°C. In the problem below: Would 0°C in this situation be measured or exact. I assume measured but since it has no decimal then there would be no significant figures for it. If that is the case and 0°C has no sig figs then do you move to the next lowest sig fig. OR does it have 1 sig fig?
Here is the example problem: 3. How many grams of chlorine gas (Cl2) are present in a 150. liter cylinder of chlorine held at a pressure of
1.00 atm and 0°C?
Here is the students work: 