Homework Help: chemistry

Posted by smiley on Friday, August 10, 2007 at 6:26pm.

experiment: Gravimetric determination of moisture in fertilizer samples
1. What are the advantages of weighing by difference to direct weighing when using an analytical balance?
2. Why are the samples grinded before drying in the oven?

Weighing by difference minimizes errors in the balance, weights, and procedure. For example, suppose a 1 g weight actually had a mass of 2 grams. I know tht won't happen but suppose it did. The mass you determine might be 1.500 but you would determine it as 2.500. Then suppose the next weighing is 2.5500 (actual mass is 1.550). Subracting 2.550 - 2.500 = 0.050 g and subtracting 1.550 - 1.500 = 0.05 g. That is you get the same answer although the mass of the weight was not correct. Solid samples are ground before drying in order to increase the surface area of the sample so that moisture is more readily driven out of the sample.

No one has answered this question yet.

Answer this Question

Related Questions

chemistry - Experiment: Gravimetric Determination of Phosphorus in Fertilizer ...
chemistry - Describe how you would weigh your KHP samples, if you didn’t ...
physics - A decorative piece consists of a 20cm long uniform brass rod weighing ...
Chemistry - Why would you use weighing paper instead of filter paper for ...
Pre Calc - Determine how many orders of magnitude the quantities differ. A ...
ipc - Arrange the following from the most work to the least. For each instance, ...
Geometry - On one side of a scale there are 6 coins, 3 weighing 2 grams each and...
physics - 1) Two people sit on a park bench 6.0 ft long, weighing 160 lb. A boy ...
science - Arrange the following from the most work to the least. For each ...
algebra - how can 2 boys weighing 100lbs each and a man weighing 200lbs cross ...

For Further Reading

First Name:
School Subject:
Answer: