Science Buddies: "Ask an Expert"

mY topic is "how pH affects the lifespan of tadpoles?"
what pH levels should i use?
what materials should i use for the different pH levels?
PLZ repond asap.
thanks

Hi!

Here is a site that can help you in your experiment:

1. http://youth.net/nsrc/sci/sci045.html#anchor785731

It is the same thing that you are doing. So, you should be able to find the ph level and materials. However, if you don't want to find out the answer DO NOT scroll down on the website a lot.

Hope this helps!

Greetings,

If you haven't looked at the website Jessica posted, I would strongly suggest that you DON'T. It's always harder to repeat someone else's experiment. You should always try to come up with your own ideas and own ways of doing things. Lots of times, you'll actually be using slightly different conditions and testing slightly different hypotheses.

Getting back to pH. At a bare minimum, you'll want to test pond water with a neutral pH (i.e. pH 7.0), something acidic (less than 7.0), and something basic (more than pH 7.0). Which solutions will use will depend a bit on which materials you have available.

For example, say you wanted to test whether tadpoles grow well at a pH of 2.0. It turns out that the pH of lemon juice is around 2.0. However, your tadpoles might not develop well because you're trying to grow them in lemon juice instead of pond water. So in this case, you wouldn't actually be testing your hypothesis.

Instead, you should have pond water for all three conditions and add acid or base solution (in a small volume) so that your tadpoles are actually developing in pond water that is at different pH levels. Please let me know if this doesn't make sense; it's very important for your experiment.

So, to figure out the pH of the solutions, you'll either need a pH meter (expensive, but your school may have one) or pH paper (cheaper). Do you have either of these things?

As for acids and bases, are you in high school or in middle school? High school chemistry labs often have acids and bases that you could use, but you'd have to be VERY careful because they're dangerous.

If you're in middle school, there are chemicals around your house that we could use instead. For example, vinegar is actually acetic acid, and would be perfect for this experiment.

So get back to us with regards to which grade you're in, and we can help you out some more. And if none of this makes sense, please let us know.

Best of luck. I hope this post was helpful.

Linh