Rate of Reaction Graph - Gas Produced I did a reaction and I measured the volume of gas produced against time. I need to find the rate constant of the reaction. 

I am trying to plot a graph of ln(vol of gas produced) against time so that the gradient will be equal to -k so i can calculate the rate constant k. I am using the equation ln[A]t = -kt + ln[A]o

The problem is I can't plot ln0. I timed the reaction every 5 mins and gas wasn't produced until 15mins had passed. This means that the volume of gas produced for time values 0, 5 and 10 mins is 0cm^3, but ln0 doesn't exist. 

How do I use my data to create a graph to calculate the rate constant?

My results were: 

Time 0___5___10___15___20___25___30___35___40___45___50___55___60 ____(in mins)

Vol _0___0___0_____5___10___18____22___28___36___44___51____60____70___(in ml produced)
I think the first bit of gas produced probably dissolved in the water, so you didn't see it for a little while. 

You can skip your three initial "points" with zero volume, and you're not going to have $\ln(0)$, which is what's hanging you up. Note that you did this in your report, and why!

Do a linear fit with the remaining points. Your y-intercept will be $\ln \mathrm{[A]}_0$ and your slope will be $-k$. It's not a terribly good fit.