Please Help Why is laboratory safety important? Describe a scenario illustrating your reason(s).

Chemistry

1 answer:

Virty [35]2 years ago

3 0

So that you can learn while being safe. Wearing goggles, for eye protection when dealing with chemicals

You might be interested in

The experiment above is repeated, but instead of extracting once with 6 mL the extraction is done three times with 2 mL of dichl

nevsk [136]

Complete Question

A student is extracting caffeine from water with dichloromethane. The K value is 4.6. If the student starts with a total of 40 mg of caffeine in 2 mL of water and extracts once with 6 mL of dichloromethane

The experiment above is repeated, but instead of extracting once with 6 mL the extraction is done three times with 2 mL of dichloromethane each time. How much caffeine will be in each dichloromethane extract?

Answer:

The mass of caffeine extracted is $P = 39.8 \ mg$

Explanation:

From the question above we are told that

The K value is $K = 4.6$

The mass of the caffeine is $m = 40 mg$

The volume of water is $V = 2 mL$

The volume of caffeine is $v_c = 2 mL$

The number of times the extraction was done is n = 3

Generally the mass of caffeine that will be extracted is

$P = m * [\frac{V}{K * v_c + V} ]^3$

substituting values

$P = 40 * [\frac{2}{4.6 * 2 + 2} ]^3$

$P = 39.8 \ mg$

6 0

3 years ago

A rotameter calibration curve (flow rate versus float position) obtained using a liquid is mistakenly used to measure a gas flow

Veronika [31]

Answer:

I would expect the gas rate determined in this manner to be too low

Explanation:

A Rotameter can be designed to respond to the sensitivity of density, velocity, to measure the flow rate of liquid or gas enclosed in a tube. Liquids are denser than gas, and since the gas rate to be determined needed to respond to the velocity head alone of the rotameter so as to bring the forces in the tube equilibrium. Knowing if there is no flow, then the float would remain at the bottom, so gas has to flow at a higher rate compared to the liquid so the float would be in a similar position making it easier to measure the flowrate. This leaves the gas rate to be determined too low.