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3 years ago

Determine whether or not each ion contributes to water hardness.

Chemistry

1 answer:

Virty [35]3 years ago

4 0

Answer: The ion that contribute to water hardness are:

--> a. Ca2+

--> b. (HCO)3^- and

--> c. Mg2+

While K+ DOES NOT contribute to water hardness.

Explanation:

WATER in chemistry is known as a universal solvent. This is so because it is polar in nature and dissolves most inorganic solutes and some polar organic solutes to form aqueous solutions. It is composed of elements such as hydrogen and oxygen in the combined ratio of 2:1.

Water is said to be HARD if it does not lather readily with soap. There are two types of water hardness:

--> Permanent hardness: This is mainly due to the presence of CALCIUM and MAGNESIUM ions in the form of soluble tetraoxosulphate(VI) and chlorides. These ions are removed by adding washing soda or caustic soda.

--> Temporary hardness: This is due to the presence of calcium HYDROGENTRIOXOCARBONATES. It can be removed by boiling and using slaked lime.

Therefore from the above given ions, Ca2+,(HCO)3^- and Mg2+ contributes to water hardness.

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3 years ago

Which pair of elements is in the same period? (Check ALL that apply) *

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Answer:

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Explanation:

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State which of the following set of quantum number would be possible and which would be permissible for an electron in an atom.

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Answer:

The correct option is: e) n=4, l=3, $m_{l}$ = - 2 , $m_{s}$ = - 1/2

Explanation:

The four quantum numbers that describe the electrons in an atom are: The principal: n, azimuthal: l, magnetic: m, and spin: s.

For a given electron, the values of the quantum numbers should be in the given range- principal quantum number: n ≥ 1;

azimuthal quantum number: 0 ≤ l ≤ n − 1;

magnetic quantum number: −l ≤ $m_{l}$ ≤ +l;

spin quantum number: −s ≤ $m_{s}$ ≤ +s

Now, for n= 4,

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The value of $m_{l}$ for l= 3 : -3 to +3 = -3, -2, -1, 0, +1, +2, +3

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