123 Viscosidad

Time for water = (73.82 ± 0.01) s

Percentage uncertainty = 0.01 / 73.82 • 100 = 0.0135 %

Taking k, the density of water p = 998 kgm-3 and the dynamic viscosity ηd = 1.02x10-3 Nsm-2 (the dynamic viscosity is considered data

K = (p / ηd)•t

K = 998 kgm-3 / 1.02x10-3 Nsm-2 • 73.82s = 72227803.92 kg/(Pa•m3)

K = 72227803.92 kg/(Pa•m3)

Ethanol:

Conclusions:

During this experiment we have calculated the constant of this particular viscometer (every viscometer has a different K) with water as a reference liquid (we should have used distilled water but there was not any left in the lab). K = 72227803.92 kg/(Pa•m3). To determine the viscosity of acetone and ethanol we just need the constant of the viscometer and the density of the liquids we are interested in measuring the viscosity of.

Labor risk prevention:

The risk factors involving this practice are:

For the work area:

• The conditions of the infrastructure the practice took place, the Physics building in this case.

• The tidiness and cleanliness.

• The lighting.

• The environment conditions.

• The deficient maintenance of the facilities.

For the prevention of these risks:

• Be respectful with each other’s space in the laboratory so everyone has their space and can work with freedom of movement.

• The floors must be stable and not slippery.

• There must be fire detectors and all kinds of fire prevention equipment (fire or something else). They must be accessible and easy to use.

• Maintain the lab and all the equipment clean.

• Eliminate all the waste we accumulate during our time in the lab that can cause accidents or pollute the work environment.

• Renovate the air in the laboratory, make sure there is enough ventilation available.

• Avoid extreme temperatures and humidity.

• There must be a 1st aid kit in case of accident. Also even though it is not the chemistry laboratory and the use of acids is not so common there should be a shower easily located in case we spill some kind of hazardous substance on us that has to be cleaned immediately.

Risks involving material and equipment:

• Cuts or any other kind of injuries.

Prevention:

• All the material used for each practice must be the proper equipment or at least a really close dupe.

• Both the student and the professor must know how to manipulate the material before using it.

• Must use globes, lab coat and glasses when in the lab. Other measures can be necessary depending on the practice that you are going

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