Here we're told that a sample of neon gas exerts a pressure of 1.85 atmospheres inside a cylinder. Some nitrogen gases also present at a pressure of 500 tour. What is the total pressure inside the cylinder? So remember we just learned about the law of partial pressures, which tells us that the total pressure felt inside of a container, or in this case a cylinder, comes from adding up the partial pressures of each gas present.

So in the container we have neon gas and we also have nitrogen gas. The total pressure is when you add their partial pressures together. Now the issue is we don't have the same units for these gases. Neon is in atmospheres but nitrogen is in tours. Since atmospheres is a standard unit we usually use for pressure, let's convert the Tor into atmospheres. So we're going to have 500 Tor and remember that for everyone atmosphere that's 760 tour.

So when we do that, we're going to get as our atmospheres 0.65789 atmospheres, take that and plug it in. And when we do that, we're going to get a total pressure of 2.50789 atmospheres. Within our question, 1.85 has three sig figs, 500 only has one sig fig here. If we went by one sig fig, this would round up to three, which is a pretty big round there in terms of our value.

So it's just better to go. Let's go with the three sig figs in this 1.85. Again, the question isn't asking for a number of sig figs in your final answer. We're doing this as continuous practice in terms of determining sigfigs. Again, better to go with three sig figs. I know it's not the least number of sig figs, but going from 2.5 to 3 three atmospheres is such a big increase. Better just to go with three sig figs and then we have 2.51 atmospheres at the end.

So now that we've seen this question, let's move on to a next video.