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1 year ago

The density of lithium is 0. 546 g/cm3. what volume is occupied by 3. 66 x 10 23 atoms of lithium?

Chemistry

1 answer:

s344n2d4d5 [400]1 year ago

3 0

The volume occupied by 3.66 x $10^{23}$ atoms of lithium is 7.73 $cm^3$

<h3>What is Density?</h3>

The density of a substance is defined as the mass of the substance per unit volume. It is often denoted by the symbol ρ

The density of a substance is given by,

$\rho = \frac{m}{V}$

The mass of a substance is the measure of the amount of matter present in it. It is generally measured in grams (g) or kilograms (kg).

The volume of a substance is defined as the amount of 3D space occupied by it.

<h3>What is Mole Concept?</h3>

It is a concept which uses mole as a unit to measure the number of atoms, molecules or ions.

A mole is defined as the amount of substance which has the same number of elementary particles as there are atoms in 12 grams of $\ce{^{12}C}$

1 mole = Avogadro's number = 6.022 x $10^{23\\$ atoms

<h3>Steps to find out the volume</h3>

Molar Mass of Lithium = 6.94 g/mol

1 mole of Lithium has 6.022 x $10^{23}$ atoms

3.66 x $10^{23}$ atoms of lithium has molar mass = $\frac{6.94 g}{6.022\times10^{23} } \times 3.66 \times 10^{23}$

$m = 4.218 g$

Substitute in density formula,

$\rho = \frac{m}{V}$

$V = \frac{m}{\rho}$

$=\frac{4.218g}{0.546g/cm^3}$

= 7.73 $cm^3\\$

Therefore, 3.66 x $10^{23}$ atoms of lithium occupies 7.73 $cm^3\\$ of volume.

Learn more about the mole concept:

brainly.com/question/1427235

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Answer:

An halogen addition reaction, particularly bromine addition, could be used to check if the hydrogenation has completed.

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A simple organic reaction is the halogen addition reaction, which occur between the halogen molecule and the double bond of the alkene. Basically, the pi electrons of the double bond attacks a relatively electrophilic halogen atom following a mechanism that leads to the addition of two halogen atoms to the double bond. As a consequence the alkene transforms into an haloalkane.

Also, a commonly used halogen is bromine, as it has a reasonable reactivity and it has red colour, which allows to monitor the progression of the reaction.

Taking all this in account, we can say that using a bromine addition reaction to the alkene it's a good option to check the completion of the hydrogenation.

Note that the bromine will react only if the double bond is present. So, if the hydrogenation has completed, the reaction won't occur. Using bromine will be the best option, as it is red coloured. That means that is we add bromine to an incomplete hydrogenation, as it will react with the alkene, the colour should disappear.

In other words, to check if the hydrogenation reaction has completed, we should add bromine and see what happens to the colour. If it doesn't change, then the hydrogenation reaction has completed.

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3 years ago

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Explanation:

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For a hypothetical reaction:

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