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chubhunter [2.5K]
3 years ago
5

Calculate the number of atoms in a 7.91×103 g sample of calcium.

Chemistry
1 answer:
frutty [35]3 years ago
4 0
I’m doing this for more questions to ask lamo
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The solubility of KCl is 3.7 M at 20 °C. Two beakers each contain 100. mL of saturated KCl solution: 100. mL of 4.0 M HCl is add
JulijaS [17]

Answer:

a)The Ksp was found to be equal to 13.69

Explanation:

Terminology

Qsp of a dissolving ionic solid — is the solubility product of the concentration of ions in solution.

Ksp however, is the solubility product of the concentration of ions in solution at EQUILIBRIUM with the dissolving ionic solid.

Note that if Qsp > Ksp , the solid at a certain temperature, will precipitate and form solid. That means the equilibrium will shift to the left in order to attain or reach equilibrium (Ksp).

Step-by-step solution:

To solve this: 

#./ Substitute the molar solubility of KCl as given into the ion-product equation to find the Ksp of KCl.

#./ Find the total concentration of ionic chloride in each beaker after the addition of HCl. We pay attention to the amount moles present at the beginning and the moles added.

#./ Find the Qsp value to to know if Ksp is exceeded. If Qsp < Ksp, nothing will precipitate.

a) The equation of solubility equilibrium for KCL is thus;

KCL_(s) ---> K+(aq) + Cl- (aq)

The solubility of KCl given is 3.7 M.

Ksp= [K+][Cl-] = (3.7)(3.7) =13.69

The Ksp was found to be equal to 14.

In pure water KCl

Ksp =13.69 KCl =[K+][Cl-]

Let x= molar solubility [K+],/[Cl-] :. × , x

Ksp =13.69 = [K+][Cl-] = (x)(x) = x²

x= √ 13.69 = 3.7 M moles of KCl requires to make 100mL saturated solutio

37M moles/L

The Ksp was found to be equal to 14.

4.0 M HCl = KCl =[K+][Cl-]

Let y= molar solubility :. y, y+4

Ksp =13.69= [K+][Cl-] = (y)(y*+4)

* - rule of thumb

Ksp =13.69= [K+][Cl-] = (y)(y*+4)= y(4)

13.69=4y:. y= 3.42 moles/100mL

y= 34.2moles/L

8 M HCl = KCl =[K+][Cl-]

Let b= molar solubility :. B, b+8

Ksp =13.69= [K+][Cl-] = (b)(b*+8)

* - rule of thumb

Ksp =13.69= [K+][Cl-] = (b)(b*+8)= b(8)

13.69=8b:. b= 1.71 moles/100mL

17.1 moles/L

Therefore in a solution with a common ion, the solubility of the compound reduces dramatically.

8 0
3 years ago
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Using the VSEPR theory , what would the representation mean A central atom with 2 connected atoms atom with I lone pair of Jone
VLD [36.1K]

Answer:

The molecule has a bent geometry

Explanation:

Let us look again at the principles of VSEPR theory. The shape of a molecule depends on the number of electron pairs that surround the valence shell of the central atom in the molecule.

Lone pairs distort the molecular geometry away from what is expected on the basis of VSEPR theory.

The molecule described in the question has the form AEX2. Two substituents and one lone pair form three electron domains around the central atom. The expected geometry is trigonal planar but the observed molecular geometry is bent because of the lone pairs present.

3 0
3 years ago
Please identify each element associated with the orbital notation or electron configuration. Note: One “slash” is one electron,
mylen [45]

Picture is upside

Explanation:

I can't read upsidedown

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Repeating many forms a crystal structure inside each of these repeated units is the ?
djyliett [7]

Answer:

gggzbjv

Explanation:

vhbbn

nnkjj

vjhgnkj

jjjjjjj

7 0
2 years ago
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All of the following use digitized signals to encode and transmit information EXCEPT:
eimsori [14]

Answer:

Record players

Explanation:

In a record player, a stylus vibrates as it follows a spiral groove cut into the surface of the rotating record.

The vibrations (analogue) are converted into electrical signals and fed into an amplifier to produce the sounds you hear

Fiber optic cables, Wi-Fi devices, and flat screen TVs use digitized signals to encode and transmit information

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