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3 years ago

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Please help 10 points!!!

1 answer:

dalvyx [7]3 years ago

6 0

<span>the average atomic mass of this element is 39.95 u</span>

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Explain how original mass of dry ice compares with the mass of carbon dioxide gas?

MAVERICK [17]

The freezing temperature at a normal sea level air pressure is negative 78.5 degrees.

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3 years ago

Use the data given below to construct a Born-Haber cycle to determine the second ionization energy of Ca. Δ H°(kJ) Ca(s)→Ca(g) 1

Drupady [299]

Answer : The value of second ionization energy of Ca is 1010 kJ.

Explanation :

The formation of calcium oxide is,

$Ca(s)+\frac{1}{2}O_2(g)\overset{\Delta H_f}\rightarrow CaO(s)$

$\Delta H_f^o$ = enthalpy of formation of calcium oxide = -635 kJ

The steps involved in the born-Haber cycle for the formation of $CaO$ :

(1) Conversion of solid calcium into gaseous calcium atoms.

$Ca(s)\overset{\Delta H_s}\rightarrow Ca(g)$

$\Delta H_s$ = sublimation energy of calcium = 193 kJ

(2) Conversion of gaseous calcium atoms into gaseous calcium ions.

$Ca(g)\overset{\Delta H_I_1}\rightarrow Ca^{+1}(g)$

$\Delta H_I_1$ = first ionization energy of calcium = 590 kJ

(3) Conversion of gaseous calcium ion into gaseous calcium ions.

$Ca^{+1}(g)\overset{\Delta H_I_2}\rightarrow Ca^{+2}(g)$

$\Delta H_I_2$ = second ionization energy of calcium = ?

(4) Conversion of molecular gaseous oxygen into gaseous oxygen atoms.

$O_2(g)\overset{\Delta H_D}\rightarrow OI(g)$

$\frac{1}{2}O_2(g)\overset{\Delta H_D}\rightarrow O(g)$

$\Delta H_D$ = dissociation energy of oxygen = $\frac{498}{2}=249kJ$

(5) Conversion of gaseous oxygen atoms into gaseous oxygen ions.

$O(g)\overset{\Delta H_E_1}\rightarrow O^-(g)$

$\Delta H_E_1$ = first electron affinity energy of oxygen = -141 kJ

(6) Conversion of gaseous oxygen ion into gaseous oxygen ions.

$O^-(g)\overset{\Delta H_E_2}\rightarrow O^{2-}(g)$

$\Delta H_E_2$ = second electron affinity energy of oxygen = 878 kJ

(7) Conversion of gaseous cations and gaseous anion into solid calcium oxide.

$Ca^{2+}(g)+O^{2-}(g)\overset{\Delta H_L}\rightarrow CaO(s)$

$\Delta H_L$ = lattice energy of calcium oxide = -3414 kJ

To calculate the overall energy from the born-Haber cycle, the equation used will be:

$\Delta H_f^o=\Delta H_s+\Delta H_I_1+\Delta H_I_2+\Delta H_D+\Delta H_E_1+\Delta H_E_2+\Delta H_L$

Now put all the given values in this equation, we get:

$-635kJ=193kJ+590kJ+\Delta H_I_2+249kJ+(-141kJ)+878kJ+(-3414kJ)$

$\Delta H_I_2=1010kJ$

Therefore, the value of second ionization energy of Ca is 1010 kJ.

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3 years ago

How do I rank the following elements by increasing electronegativity: sulfur, oxygen, neon, aluminum

irinina [24]

Aluminum, Sulfur, Oxygen, Neon

7 0

3 years ago

Read 2 more answers

Iron reacts with oxygen to produce iron oxide rust this reaction is representative in an equation as to FE plus XO22FE203 identi

igomit [66]

The balanced equation :

4Fe + 3O₂⇒ 2Fe₂O₃

<h3>Further explanation</h3>

Given

Rust reaction

Required

Balanced equation

Solution

Reaction

Fe + O₂⇒ 2Fe₂O₃

For a simple equation where one of the reaction coefficients is known, we can immediately add the corresponding coefficient using the principle that the number of atoms of <em>the components in the reactants and products is the same. </em>

In the above reaction :

Fe, left=1, right = 4, so coefficient in the left=4

O, left=2, right = 6, so coefficient in the left=3

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3 years ago

Is the following chemical equation balanced?<br><br> AgNO3 + NaCl 4AgCl + NaNO3<br><br> yes<br> no

marta [7]

No. Reactants: 1 silver, 1 chlorine; products: 4 silver, 4 chlorine. Therefore, not balanced.

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3 years ago