Thread: Volume, Weight, and Density using water.

I wasn't sure quite where this question would go, because it's kind of odd. In my Biology class, we would take pieces of tissue and weigh them, then place them in vials of water to determine volume, to ultimately determine density.

I had a piece of fish muscle, and it weighed in at 14.3 grams. I then placed the flesh into the beaker and poured water over it until it reached 50 ml. At that point, it floated to the top, and I removed it from the liquid. Upon observing the beaker, I noted it had gone down to about 45 ml, suggesting to me that the volume was 5 ml.

Now here's where I get confused. In the book we're working from, it says to divide the weight of the specimen by the volume to get the density. The empty space says the answer is in g/ml. To me, those mean divide 14.3 by 5, but I'm pretty sure that grams and ml are not compatible in that way.

I do know, of course, that because the tissue was floating, the density should be below 1.0 g/ml, the density of water.

Do I need to convert something? Was the tissue sample (which, the professor said, had been frozen and thawed several times) defective? Is it something in my process?

I would really appreciate some help!!!

Originally Posted by Entropy

I wasn't sure quite where this question would go, because it's kind of odd. In my Biology class, we would take pieces of tissue and weigh them, then place them in vials of water to determine volume, to ultimately determine density.

I had a piece of fish muscle, and it weighed in at 14.3 grams. I then placed the flesh into the beaker and poured water over it until it reached 50 ml. At that point, it floated to the top, and I removed it from the liquid. Upon observing the beaker, I noted it had gone down to about 45 ml, suggesting to me that the volume was 5 ml.

Now here's where I get confused. In the book we're working from, it says to divide the weight of the specimen by the volume to get the density. The empty space says the answer is in g/ml. To me, those mean divide 14.3 by 5, but I'm pretty sure that grams and ml are not compatible in that way.

I do know, of course, that because the tissue was floating, the density should be below 1.0 g/ml, the density of water.

Do I need to convert something? Was the tissue sample (which, the professor said, had been frozen and thawed several times) defective? Is it something in my process?

I would really appreciate some help!!!

I think the volume you got that is 5ml is not correct because the object was not completely submerged into the water (it was floating). To get an accurate volume use any laboratory apparatus that could help to push the object into the water. (Note: Use that apparatus that has very less volume compared to an object).