How many grams of CoCl2 in 1/2 liter would be used to make a 1.0 molar solution? (can you show steps please?)

A researcher was attempting to quantify the amount of dichlorodiphenyltrichloroethane (DDT) in spinach with gas chromatography u

devlian [24]

Answer:

0.0136mg DDT / g spinach

Explanation:

Quantification in chromatography by internal standard has as formula:

RF = Aanalyte×Cstd / Astd×Canalyte (1)

Where RF is response factor, A is area and C is concentration

Replacing with first experiment values:

RF = 5019×3.20mg/L / 8179×6.37mg/L

RF = 0.308

In the next experiment, final concentration of chloroform was:

11.45mg/L × (1.25mL / 25.00mL) = 0.5725mg/L

From (1), it is possible to write:

Aanalyte×Cstd / Astd×RF = Canalyte

Replacing:

6821×0.5725mg/L / 14061×0.308 = Canalyte

Canalyte = 0.9017mg/L

as the sample was made from 0.750mL of extract. Concentration of extract is:

0.9017mg/L × (25.00mL / 0.750mL) = 30.06mg/L. As the extract has a volume of 2.40mL:

30.06mg/L × 2.40x10⁻³L = 0.07213mg of DDT in the extract

As the extract was made from 5.29g of spinach:

0.07213mg of DDT in the extract / 5.29g spinach = 0.0136mg DDT / g spinach

5 0

3 years ago

What makes carbon monoxide

Leto [7]

Carbon monoxide is a colorless, odorless, tasteless gas produced by burning gasoline, wood, propane, charcoal or other fuel. Improperly ventilated appliances and engines, particularly in a tightly sealed or enclosed space, may allow carbon monoxide to accumulate to dangerous levels.

5 0

3 years ago

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A student inflates a balloon with helium then places it in the freezer. The student should expect

g100num [7]

Answer:

The frozen balloon shrank because the average kinetic energy of the gas molecules in a balloon decreases when the temperature decreases. This makes the molecules move more slowly and have less frequent and weaker collisions with the inside wall of the balloon, which causes the balloon to shrink a little.

Explanation:{ BOOM}***

6 0

3 years ago

Help! I don't have the things to do this and its due TODAY! Could someone help me?

vodomira [7]

Answer:

--- The hot air inside the bottle creates an expansion and when the hot water is applied a contraction occurs, thus causing the balloon to be sucked.

--- An internal pressure is produced, joining the heat begins to decrease. As a consequence, the air molecule causes the balloon to enter the bottle thanks to the effect of the external pressure.

Explanation:

I hope I have helped with something.

4 0

3 years ago

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Methyl red is a common acid-base indicator. it has a ka equal to 6.3 × 10–6. its un-ionized form is red and its anionic form is

Maksim231197 [3]

Hello!

The pKa of an indicator tells us the pH where it changes color. The pKa of Methyl red is

$pKa=-log(Ka)=-log( 6,3*10^{-6} )=5,20$

So, at a pH=7,8, Methyl Red would be at a pH over its pKa, so it would be in its basic form. The Basic Form of Methyl Red is Yellow, so the solution would be Yellow.

Have a nice day!

7 0

3 years ago