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3 years ago

19 pts - How do you determine if something is isoelectronic?

1 answer:

5 0

Isoelectronic means equal number of electrons.

The method to determine if elements are sioelectronic is:

1) Determine the atomic number of the element (search the element in the periodic table).

2) The atomic number is equal to the number of protons (always, by definition).

3) If the atom is neutral, the number of electrons is equal to the number of protons.

3) If the species is not neutral then:

 - if it is a negative ion, add as many electrons as the magnitude of the charge of the ion

 - if iit is a positive ion, subtract as many electrons as the magnitude of the charge of the ion.

4) One by one

species atomic number charge number of electrons
number of protons

O₂, 8 0 8 (each atom)
F- 9 -1 9 + 1 = 10
Ne 10 0 10
Na 11 0 11

So, in that group only F- and Ne are isoelectronic, each with 10 electrons

Se2- 34 -2 34 + 2 = 36
Br- 35 -1 35 + 1 = 36
Kr 36 0 36
Rb+ 37 +1 37 - 1 = 36

So, in that group all are isoelectronic.

I- 53 -1 53 + 1 = 54
Xe 54 0 54
Cs 55 0 55
Ba2+ 56 +2 55 - 2 = 53

So, in that group only I- and Xe are isoelectronic.

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Find the number of moles of water that can be formed if you have 170 mol of hydrogen gas and 80 mol of oxygen gas. Express your

Sav [38]

Answer: The amount of water that can be formed is 160 moles

Explanation:

We are given:

Moles of hydrogen gas = 170 moles

Moles of oxygen gas = 80 moles

The chemical equation for the reaction of hydrogen gas and oxygen gas follows:

$2H_2+O_2\rightarrow 2H_2O$

By Stoichiometry of the reaction:

1 mole of oxygen gas reacts with 2 moles of hydrogen gas

So, 80 moles of oxygen gas will react with = $\frac{2}{1}\times 80=160mol$ of hydrogen gas

As, given amount of hydrogen gas is more than the required amount. So, it is considered as an excess reagent.

Thus, oxygen gas is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

1 mole of oxygen gas produces 2 moles of water

So, 80 moles of oxygen gas will produce = $\frac{2}{1}\times 80=160moles$ of water

Hence, the amount of water that can be formed is 160 moles

3 0

4 years ago

The reaction between nitrogen dioxide and carbon monoxide is NO2(g)+CO(g)→NO(g)+CO2(g)NO2(g)+CO(g)→NO(g)+CO2(g) The rate constan

galina1969 [7]

Answer:

$k_2=2.55\ {Ms}^{-1}$

Explanation:

Using the expression,

$\ln \dfrac{k_{1}}{k_{2}} =-\dfrac{E_{a}}{R} \left (\dfrac{1}{T_1}-\dfrac{1}{T_2} \right )$

Where,

$k_1\ is\ the\ rate\ constant\ at\ T_1$

$k_2\ is\ the\ rate\ constant\ at\ T_2$

$E_a$ is the activation energy

R is Gas constant having value = 8.314 J / K mol

$k_2=?$

$k_1=2.57\ {Ms}^{-1}$

$T_1=701\ K$

$T_2=525\ K$

$E_a=1.5\times 10^2\ kJ/mol$

So,

$\ln \:\frac{2.57}{k_2}\:=-\frac{1.5\times \:10^2}{8.314}\times \left(\frac{1}{701}-\frac{1}{525}\right)\:\:$

$k_2=\frac{2.57}{e^{\frac{352}{40796.798}}}=2.55\ {Ms}^{-1}$

7 0

3 years ago

How to find an elements atomic weight

Tju [1.3M]

To calculate the average atomic mass, multiply the fraction by the mass number for each isotope, then add them together.

3 0

3 years ago

Drag the tiles to the correct locations on the equation. Not all tiles will be used.

mel-nik [20]

Answer:

Tile 52 and three are incorrect

Explanation:

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2 years ago

Write the structural formula for a primary, a secondary, and a tertiary constitutionally isomeric alcohol of the molecular formu

9966 [12]

Answer:

The structures of all isomeric alcohols of molecular formula C5H12O along with their IUPAC names are as shown.

Their classification of primary, secondary, and tertiary alcohols are -

1-pentanol -

2-pentanol -

3-pentanol

2-methylbutan-1-ol

2-methylbutan-2-ol

3-methylbutan-2-ol

3-methylbutan-1-ol

2,2-dimethylpropanol

5 0

3 years ago