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2 years ago

5. Which statement is true about electronegativity?

Chemistry

1 answer:

Anit [1.1K]2 years ago

3 0

Answer:

Electronegativity generally increases from left to right across a period,

Explanation:

The true statement from the given choices is that electronegativity generally increases from left to right across a period.

Electronegativity is the measure of the relative tendency with which an atom of the element attract valence electrons in a chemical bond.

Across a period electronegativity increases from left to right and decreases down the group.

This is due to reduction in metallic properties as we move across the period from left to right.

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A bond formed when atoms share electrons is a(n) __________.

Amiraneli [1.4K]

Answer:

I think it is a covalent bon

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2 years ago

2.41 x 10^2 Cm to meters

Assoli18 [71]

We know that there are 100 cm in 1 m, so we can use this to convert to meters:

$(\frac{2.41x10^{2}cm}{1})*(\frac{1m}{100cm} )=2.41m$

Therefore we know that $2.41x10^{2}$ cm is equal to 2.41 m.

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2 years ago

Read 2 more answers

The bonds of oxygen molecules are broken by sunlight. The minimum energy required to break the oxygen-oxygen bond is 495 kJ/mol

olga_2 [115]

Answer:

The wavelength of sunlight is required to break the bond in one oxygen molecule is 242 nm.

Explanation:

Energy required to break the 1 mol oxygen-oxygen bond:

=495 kJ=495000J

1 mol = $6.022\times 10^{23}$ molecules

Energy required to break 1 molecule of oxygen molecule= E

= $E=\frac{495000 J}{6.022\times 10^{23}}=8.219\times 10^{-19} J$

The energy required to break the 1 molecule of oxygen is equal to enrgy of one photon of a sunlight.

$E=\frac{h\times c}{\lambda}$

where,

$\lambda$ = wavelength of the light

E = energy of the photon

h = Planck's constant = $6.63\times 10^{-34}Js$

c = speed of light = $3\times 10^8m/s$

$\lambda=\frac{h\times c}{E}$

$\lambda =\frac{6.63\times 10^{-34}Js \times 3\times 10^8m/s}{8.219\times 10^{-19} J}=2.42\times 10^{-7} m=242 nm$

The wavelength of sunlight is required to break the bond in one oxygen molecule is 242 nm.

4 0

3 years ago

Using the following thermochemical data, what is the change in enthalpy for the following reaction?

slavikrds [6]

Answer:

D. -120.9 kJ

Explanation:

According to Hess's law ,the total enthalpy change for a reaction is the sum of all changes regardless of the stages or the steps of the reaction.

$CaO + 2HCl \rightarrow CaCl_{2} + H_{2}O\ (\Delta H = -186\ kJ)$ ....(1)

$CaO + H_{2}O\rightarrow Ca(OH)_{2}\ (\Delta H = - 65 \ kJ)$

(this reaction should be reversed in order to reach the required reaction )

On reversing the reaction the sign of $\Delta H$ get reversed.

(In this case change sign from '-' to'+'. Hence $\Delta H$ = + 65 kJ)

$CaO + 2HCl \rightarrow CaCl_{2} + H_{2}O\ (\Delta H = - 186\ kJ)$ ....(1)

$Ca(OH)_{2} \rightarrow CaO + H_{2}O\ (\Delta H = + 65 kJ )$ ......(2)

Adding equation (1) and (2)

$Ca(OH)_{2} + 2HCl \rightarrow CaCl_{2} + 2H_{2}O[tex][tex]Delta H = - 186 + 65 = - 121\kJ$

$Delta H = - 121\kJ$ (It is nearly equal to -120.9 kJ)

7 0

2 years ago

Molten sodium chloride is broken down in an electrolytic cell into the elements sodium and chlorine. Where do the

barxatty [35]

Answer:Chlorine gas bubbles out of the melt above the anode. Sodium ions migrate to the cathode, where electrons enter the melt and are reduced to sodium metal

Explanation:

5 0

2 years ago