# Gas: calculating pressure

1. Mar 3, 2015

### ngu9997

1. The problem statement, all variables and given/known data
Tums react in your stomach to produce a gas. The average adult stomach expand to one liter when full. Calculate the pressure in the average adult stomach after taking 2 Tums.
2. Relevant equations
Since its asking for pressure, and the volume is given perhaps PV=nRT should be used.
Also P1V1=P2V2 might seem like a possible equation.

3. The attempt at a solution
I'm honestly not sure how to start this problem. I started with a balanced chemical equation for the reaction of the Tums (CaCO3) and the stomach acid/hydrochloric acid (HCl), which would be:
CaCO3 + 2HCl --> CaCl2 + H2O + CO2. I'm not sure where to go from here or if this is a necessary step in solving the problem. Any suggestions in where to start would be helpful.

2. Mar 3, 2015

### Staff: Mentor

What is the weight of a "tum"?
How much CO2 do you get from the reaction? (In any unit you like)

3. Mar 3, 2015

### ngu9997

One tums tablet is 250 mg. So two tums tablets would be 500 mg or .5 grams. If so, then would .0049 moles of CO2 sound correct?

Last edited: Mar 3, 2015
4. Mar 3, 2015

### Staff: Mentor

Yes.

What is a body temperature?

5. Mar 3, 2015

### ngu9997

37 degrees Celsius. Converted to kelvins it would be 310.15 K. Would I use this as the temperature in the equation PV=nRT?

6. Mar 3, 2015

### Staff: Mentor

Sure. I think everything apart from pressure is known now.