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3 years ago

Why do some elements form double and triple bonds during bonding

Chemistry

1 answer:

jekas [21]3 years ago

4 0

Explanation:

Elements need a total of eight electrons to gain stability and look like a noble gas. So, they sometimes need sharing of two, four or even six electrons to complete their octate. So, they form double and triple covalent bonds. One more the reason is the interaction between the p orbitals of the combining atoms. for example A double bond, as in ethene H2C=CH2, arises from one combination of the s orbitals and one combination of the p_y orbitals.

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125 ml of nitrogen gas is collected at 70.0 degrees Celsius. The pressure

dybincka [34]

Answer: Volume of the gas at STP is 22.53 L.

Explanation:

Given : Volume = 125 mL (as 1 mL = 0.001 L) = 0.125 L

Temperature = $70^{o}C = (70 + 273) K = 343 K$

Pressure = $125 kPa = 125 kPa \times \frac{0.01 atm}{1 kPa} = 1.25 atm$

According to the ideal gas equation, the volume of given nitrogen gas is calculated as follows.

PV = nRT

where,

P = pressure

V = volume

n = number of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into above formula as follows.

$1.25 atm \times V = 1 mol \times 0.0821 L atm/mol K \times 343 K\\V = \frac{1 mol \times 0.0821 L atm/mol K \times 343 K}{1.25 atm}\\= \frac{28.1603}{1.25} L\\= 22.53 L$

Hence, volume of the gas at STP is 22.53 L.

5 0

2 years ago

Arrange the components of the electron transport chain in order from least electronegative to most electronegative thereby indic

choli [55]

The least electronegative component in the electron transport chain is the Hydrogen ion.
The more electronegative is NAD+
The other component is H2O,
Next are the energy carrier molecules which are the ADP and ATP
And finally, the most electronegative is O2.

3 0

3 years ago

Match the following items. Match the items in the left column to the items in the right column. 1. general or nonspecific observ

ivann1987 [24]

when column B is like the attached pic: (missing in your question)

so the matches will be like that:

1- Qualitative :

as Qualitative is a general or nonspecific observation, they also don't require

measurements and even can't be measured, that is because of the reality is

being approximated only. It describes qualities and uses opinion

2- Hypothesis :

as a hypothesis is an educated guess quantitative, and it is a prediction stated

in " If and then " form. a hypothesis to be valid need a research such as:

-Encyclopedia & state and local research facilities & scientific journals.

3- Direct relationship:

as a Direct relationship is when two variable change in the same direction,

and one remaining larger than the other by the same factory.

- this is a type of a relationship in which there is a change with one variable, and corresponding with the change in the other. and because this corresponding change with the other variable in the same direction so it refers to a positive relationship.

4- Quantitative:

as Quantitative is a measured observation, It's an information or data based

on quantities obtained. And using numbers, equipment and standard units.

5- Control :

as control is standard, reference data or experiment qualitatively. this is what

you compare your experimental results to. This is for comparing results, it

used as a standard for comparison and use baseline measurements to use in

the comparing.

6- Theory :

as Theory is a presently accepted explanation of how something happened.

Scientifically acceptable general principles to explain phenomena. It the

general or abstract principles of the science. for example the wave theory of

light.

7- Law :

as a law is a statement that explains what something does under the same

conditions. when we take about law in science, it is a general rule to explain

the observations in the form of a mathematical statement. Scientific law may

be stated in words or expressed as a mathematical equations.

8- Best fit curve:

as best fit curve is a curve drawn to average the data's deviations direct

relationship. It is a process of constructing a curve that has best fit to a

series of data points.

7 0

3 years ago

The combustion of ethene in the presence of excess oxygen yields carbon dioxide and water: c2h4 (g) + 3o2 (g) → 2co2 (g) + 2h2o

meriva

Answer:

$\boxed{-267.5}$

Explanation:

You can calculate the entropy change of a reaction by using the standard molar entropies of reactants and products.

The formula is

$\Delta_{r} S^{\circ} = \sum_n {nS_{\text{products}}^{\circ} - \sum_{m} {mS_{\text{reactants}}^{\circ}}}$

The equation for the reaction is

C₂H₄(g) + 3O₂(g) ⟶ 2CO₂(g) + 2H₂O(ℓ)

ΔS°/J·K⁻¹mol⁻¹ 219.5 205.0 213.6 69.9

$\Delta_{r} S^{\circ} = (2\times213.6 + 2\times69.9) - (1\times219.5 + 3\times205.0)\\\\= 567.0 - 834.5 = \boxed{-267.5 \text{ J}\cdot\text{K}^{-1} \text{mol}^{-1}}$

3 0

3 years ago

Imagine you are given a mystery element. It is, however, a discovered and known element. You may perform a maximum of two observ

miv72 [106K]

The classification of it being a metal, nonmetal, or metalliod will be useful in the process of elimination to determine what it is. Then for the second test, meauring the atomin radius will narrow it down quicker to the mystery elemet's name.

Since you determined what part of the periodic table it's on, then when measuring the atomic radius, you should be able to pinpoint what the element is more surely.

6 0

3 years ago

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