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3 years ago

The ammonia molecule in the diagram has the observed bond orientation because ...

Chemistry

1 answer:

aivan3 [116]3 years ago

3 0

Answer:

Nitrogen has four pairs of electrons: 3 bonds and 1 lone pair in the valence shell;
Electrons repel one another based on the VSEPR theory;
Nitrogen has a total of 7 protons (its atomic number is 7) in its nucleus.

Explanation:

The shape and the bond orientation of molecules and ions are both explained by the valences shell electron pair repulsion theory (VSEPR).

Ammonia, $NH_3$ , is a molecule which contains three N-H bonds, as well as one lone pair on nitrogen. According to the VSEPR theory, molecules try to acquire a shape which would minimize the repulsion exhibited by the electron clouds present, that is, between the bonding (shared in a bond) and non-bonding (lone pair) electrons.

In VSEPR, our main step is to calculate the steric number, this is the sum of the number of bonds (ignoring the multiplicity of any bond) and the lone pairs on a central atom. In ammonia, we have 3 bonds and 1 lone pair, totaling to a steric number of 4. A steric number of 4 without any lone pairs on a central atom and just bonds would yield a tetrahedral shape with bond angles of $109.5^o$ .

Now, in this case, since we have a lone pair instead of a bond, it is repelling stronger decreasing the bond angles to about $107^o$ .

The greater the number of lone pairs, the lower the angle becomes.

To summarize:

Nitrogen has four pairs of electrons: 3 bonds and 1 lone pair in the valence shell;
Electrons repel one another based on the VSEPR theory;
Nitrogen has a total of 7 protons (its atomic number is 7) in its nucleus.

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Determine the expected diffraction angle for the first-order diffraction from the (111) set of planes for FCC nickel (Ni) when m

faust18 [17]

Answer:

56°

Explanation:

First calculate $a:$

$a=2 R \sqrt{2}=2(0.1246) \sqrt{2}=0.352 \mathrm{nm}$

The interplanar spacing can be calculated from:

$d_{111}=\frac{a}{\sqrt{1^{2}+1^{2}+1^{2}}}=\frac{0.352}{\sqrt{3}}=0.203 \mathrm{nm}$

The diffraction angle is determined from:

$\sin \theta=\frac{n \lambda}{2 d_{111}}=\frac{1(0.1927)}{2(0.2035)}=0.476$

Solve for $\theta$

$\theta=\sin ^{-1}(0.476)=28^{\circ}$

The diffraction angle is:

$2 \theta=2\left(28^{\circ}\right)=56^{\circ}$

4 0

3 years ago

Write the balanced electrochemical reaction for when zinc reacts with a copper solution. Label what is being oxidized and what i

Fed [463]

The balanced equation would be $Zn + Cu^{2+} ---- > Cu + Zn^{2+}$

<h3>Electrochemical equations</h3>

Zn reacts with Cu solution according to the following equation:

$Zn + Cu^{2+} ---- > Cu + Zn^{2+}$

In the reaction, $Cu^{2+}$ is reduced according to the following: $Cu^{2+} + 2 e^- -- > Cu$

While Zn is oxidized according to the following: $Zn - 2e^- --- > Zn^{2+}$

Thus, giving the overall equation of; $Zn + Cu^{2+} ---- > Cu + Zn^{2+}$

More oxidation-reduction equations can be found here: brainly.com/question/13699873

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1 year ago

It takes 281.7 kJ of energy to remove 1 mole of electrons from the atoms on the surface of lithium metal. If lithium metal is ir

Alex17521 [72]

Answer:

The maximum kinetic energy of electron is = 2.93 × $10^{-19}$ Joule

Explanation:

We know that total energy

$E = \frac{hc}{\lambda}$ ------------ (1)

Here h = plank's constant = 6.62 × $10^{-34}$ J s

c = speed of light = 3 × $10^{8}$ $\frac{m}{s}$

$\lambda$ = 261 nm = 261 × $10^{-9}$ m

Put all these values in equation (1) we get

E = 7.6 × $10^{-19}$ J

We know that

Total energy = Energy to remove an electron + K.E of electron

Energy to remove an electron = $\frac{281.7 (1000)}{(6.023)10^{23} }$

Energy to remove an electron = 4.67 × $10^{-19}$ J

K.E of electron = Total energy - Energy to remove an electron

K.E of electron = 7.6 × $10^{-19}$ - 4.67 × $10^{-19}$

K.E of electron = 2.93 × $10^{-19}$ Joule

Therefore the maximum kinetic energy of electron is = 2.93 × $10^{-19}$ Joule

3 0

3 years ago

Using the solubility graph place the substances in order from most soluble (#1) to least soluble at 40°C. KNO3, NaClO3,KBr, NaCl

mestny [16]

Answer:

NaClO₃ > KBr > KNO₃ > NaCl.

Explanation:

The attached file contains the graph with the solubility curves for the four substances, KNO₃, NaClO₃, KBr, NaCl.

To determine the solubility of each salt at a certain temperature, you read the temperature on the horizontal axis, labeled Temperature (ºC), and move upward up to intersecting the curve of the corresponding salt. Then, move horizontally up to insersceting the vertical axis, labeled Solubility (g/100g of H₂O), to read the solubility.

The higher the reading on the vertical axis, the higher the solubility.

The red vertical line that I added is at a temperature of 40ºC.

The number in blue indicate the order in which the solubility curves are intersected at that temperature:

4: NaCl: this is the lowest solubility
3: KNO₃: this is the second lowest solubility
2: KBr: this is the third lowest solubility
1: NaClO₃: this is the highest solubility.

Thus, the rank, from most soluble to least soluble is:

NaClO₃ > KBr > KNO₃ > NaCl.

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3 years ago

Please answer fast!!! what does base stand for in science

pychu [463]

There are multiple meanings for a base. A base can be a substance that accepts hydrogen ions, or it could be something that is not acidic, in other words meaning its pH is between 7 and 14.

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3 years ago