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2 years ago

What precautions must be taken when you introduce a mixture of compounds to be separated onto a liquid chromatography column?

1 answer:

5 0

<span>The slim exit of the column is first persisted with glass wool or a permeable plate in order to sustain the column packing element and keep it from getting out of the tube. Then the adsorbent solid, which is usually a silica, is firmly packed into the glass tube to make the separating column. The packing of the non-moving phase into the glass column must be done with precaution to create an even distribution of material. An even distribution of adsorbent material is very important to lessen the existence of air bubbles and/or channels inside the column. To finish preparing the column, the solvent to be used as the mobile phase is delivered through the dry column. Then the column is said to be "wetted" and the column must stay wet throughout the entire procedure. Once the column is properly prepared, the sample to be separated is placed at the top of the wet column.</span>

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A stock solution of HNO3 is prepared and found to contain 13.5 M of HNO3. If 25.0 mL of the stock solution is diluted to a final

salantis [7]

Answer : The correct option is, (C) 0.675 M

Explanation :

Using neutralization law,

$M_1V_1=M_2V_2$

where,

$M_1$ = concentration of $HNO_3$ = 13.5 M

$M_2$ = concentration of diluted solution = ?

$V_1$ = volume of $HNO_3$ = 25.0 ml = 0.0250 L

conversion used : (1 L = 1000 mL)

$V_2$ = volume of diluted solution = 0.500 L

Now put all the given values in the above law, we get the concentration of the diluted solution.

$13.5M\times 0.0250L=M_2\times 0.500L$

$M_2=0.675M$

Therefore, the concentration of the diluted solution is 0.675 M

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2 years ago

If you had a chance to get a scholarship abroad?what would you do?

Dovator [93]

Answer:

I Would bc it's the better opportunity

7 0

3 years ago

Read 2 more answers

Is this correct? please check

Reil [10]

Answer:

A is the correct option

Explanation:

batteries have chemical energy and will convert to electricity and when reached to bulb, it emits light as electromagnetic rays

4 0

2 years ago

Which of the following gives the definition of ion-dipole attraction? Select the correct answer below: O a. lon-dipole attractio

frez [133]

Answer:

Explanation:

Anions are attracted to the positive end of a dipole, while the cations are attracted to the negative end. As the size of the dipole moment or the ionic charge increases, the vastness of the attraction also increases. This type of attraction is important for solutions of ionic substances in polar liquids.

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3 years ago

The last element in any period always has:

brilliants [131]

Answer: The correct option is The properties of a noble gas.

Explanation: There are 7 periods in the periodic table.

The last element of each period are Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn) and Ununoctium (Uuo).

The electronic configuration for Helium is $1s^2$ . For He, The outermost electrons are 2.

The electronic configuration for all the other elements is $ns^2ns^6$ ( where, n = 2, 3, 4, 5, 6 and 7 respectively). For all the other gases, the outermost electrons are 8.

All these elements have stable electronic configuration and are not reactive in nature. Hence, they are considered as noble gases.

Therefore, the last element of each period always have the properties of a noble gas.

4 0

3 years ago

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