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3 years ago

Select the correct order of the GC components

1 answer:

8 0

<span>Carrier Gas, Flow Controller, Column, Detector, Recorder

</span>First we have a cylinder containing the carrier gas. From there, the carrier gas goes to the flow controller, which determines how much carrier gas we are entering into the column (it doesn’t let more gas pass through). Then, the carrier gas enters the column, which is the most important part of the device. The sample enters the column from another place: the injector. Then, the sample and the carrier gas go together across the column. The interactions between the sample and the column will determine how fast each sample component goes through the column, and so: which component gets out earlier. So, at the end, you will have isolated each substance. Then, each one passes (alone) through the detector, which measures something about the sample – this information will let you know which substance it is. Finally, the recorder provides you with the information the detector has found. Nowadays, the recorder is a computer. In the “stone age” they just used a rudimentary printer.

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Find the total number of moles of ions produced when 0.347 mol of sodium carbonate dissolves.

Ahat [919]

Answer:

molarity= 0.238 mol L-

Explanation:

The idea here is that you need to use the fact that all the moles of sodium phosphate that you dissolve to make this solution will dissociate to produce sodium cations to calculate the concentration of the sodium cations.

Na 3 PO 4 (aq) → Na + (aq) + PO3−4 (aq)

Use the molar mass of sodium phosphate to calculate the number of moles of salt used to make this solution.

3.25g⋅1 mole N 3PO4 163.9g = 0.01983 moles Na3 PO 4

Now, notice that every

1 mole of sodium phosphate that you dissolve in water dissociates to produce

3bmoles of sodium cations in aqueous solution.

4 0

2 years ago

A mysterious white powder could be powdered sugar (C12H22O11), cocaine (C17H21NO4), codeine (C18H21NO3), norfenefrine (C8H11NO2)

rodikova [14]

Norfenefrine (C₈H₁₁NO₂).

<h3>Further explanation</h3>

We will solve a case related to one of the colligative properties, namely freezing point depression.

The freezing point of the solution is the temperature at which the solution begins to freeze. The difference between the freezing point of the solvent and the freezing point of the solution is called freezing point depression.

$\boxed{ \ \Delta T_f = T_f(solvent) - T_f(solution) \ } \rightarrow \boxed{ \ \Delta T_f = K_f \times molality \ }$

<u>Given:</u>

A mysterious white powder could be,

powdered sugar (C₁₂H₂₂O₁₁) with a molar mass of 342.30 g/moles,
cocaine (C₁₇H₂₁NO₄) with a molar mass of 303.35 g/moles,
codeine (C₁₈H₂₁NO₃) with a molar mass of 299.36 g/moles,
norfenefrine (C₈H₁₁NO₂) with a molar mass of 153.18 g/moles, or
fructose (C₆H₁₂O₆) with a molar mass of 180.16 g/moles.

When 82 mg of the powder is dissolved in 1.50 mL of ethanol (density = 0.789 g/cm³, normal freezing point −114.6°C, Kf = 1.99°C/m), the freezing point is lowered to −115.5°C.

<u>Question: </u>What is the identity of the white powder?

<u>The Process:</u>

Let us identify the solute, the solvent, initial, and final temperatures.

The solute = the powder
The solvent = ethanol
The freezing point of the solvent = −114.6°C
The freezing point of the solution = −115.5°C

Prepare masses of solutes and solvents.

Mass of solute = 82 mg = 0.082 g
Mass of solvent = density x volume, i.e., $\boxed{ \ 0.789 \ \frac{g}{cm^3} \times 1.50 \ cm^3 = 1.1835 \ g = 0.00118 \ kg \ }$

We must prepare the solvent mass unit in kg because the unit of molality is the mole of the solute divided by the mass of the solvent in kg.

The molality formula is as follows:

$\boxed{ \ m = \frac{moles \ of \ solute}{kg \ of \ solvent} \ } \rightarrow \boxed{ \ m = \frac{mass \ of \ solute \ (g)}{molar \ mass \ of \ solute \times kg \ of \ solvent} \ }$

Now we combine it with the formula of freezing point depression.

$\boxed{ \ \Delta T_f = K_f \times \frac{mass \ of \ solute \ (g)}{molar \ mass \ of \ solute \times kg \ of \ solvent} \ }$

It is clear that we will determine the molar mass of the solute (denoted by Mr).

We enter all data into the formula.

$\boxed{ \ -114.6^0C - (-115.5^0C) = 1.99 \frac{^0C}{m} \times \frac{0.082 \ g}{Mr \times 0.00118 \ kg} \ }$

$\boxed{ \ 0.9 = \frac{1.99 \times 0.082}{Mr \times 0.00118} \ }$

$\boxed{ \ Mr = \frac{0.16318}{0.9 \times 0.00118} \ }$

We get $\boxed{ \ Mr = 153.65 \ }$

These results are very close to the molar mass of norfenefrine which is 153.18 g/mol. Thus the white powder is norfenefrine.

<h3>Learn more</h3>

The molality and mole fraction of water brainly.com/question/10861444
About the mass and density of ethylene glycol as an antifreeze brainly.com/question/4053884
About the solution as a homogeneous mixture brainly.com/question/637791

Keywords: a mysterious white powder, sugar, cocaine, codeine, norfenefrine, fructose, the solute, the solvent, dissolved, ethanol, normal freezing point, the freezing point depression, the identity

7 0

3 years ago

Read 2 more answers

What are the four factors that affect the natural selection?

BaLLatris [955]

Answer:

• potential for a species to increase in number

• the heritable genetic variation/ which results from mutation in dna

• the size of a population increases

• competiton for resources that are limited in that specific environment.

Explanation:

these are all factors that would affect natural selection although there are many more.

6 0

3 years ago

Sodium hydroxide is a common ingredient in drain cleaners such as Drano. The mole fraction of sodium hydroxide in a saturated aq

SVETLANKA909090 [29]

Answer:

The correct answer to this question is (c) 25.0 m

Explanation:

To solve this we list out the variables thus

mole fraction of sodium hydroxide = 0.310

Mole fraction = number of moles of a component ÷ total number of moles in the solution

Mole fraction = 0.310

In a saturaturated aqueous solution we have NaOH and water

∴ Number of moles of water molecules per unit = 1 - 0.310 = 0.690

However 0.690 moles of H₂O weighs = 0.690 mole × 18.01528 g/mol =12.43 g = 0.01243 kg of H₂O

But the molality = number of moles per Kilogram of H₂O

therefore molality of NaOH in the sample of solution =

(0.310 mol of NaOH )÷(0.01243 kg of H₂O)

= 24.93 mol/kg or ≅ 25.0 m

5 0

2 years ago

How many moles in 2.5 liters of methane gas

Zarrin [17]

Answer:

0.155836449023405

Explanation:

The molecular formula for Methane is CH4.

The SI base unit for amount of substance is the mole.

1 grams Methane is equal to 0.062334579609362 mole.

6 0

3 years ago