Tag: chemistry

Questions Related to chemistry

All the naturally occurring noble gases are non-reactive except:

chemistry the periodic table periodic trends in chemical properties alkali metals study of specific groups

  1. Argon

  2. Helium

  3. Xenon

  4. Radon

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Correct Option: C

The number of naturally occurring noble gas elements are:

chemistry the periodic table periodic trends in chemical properties alkali metals study of specific groups

  1. 8

  2. 7

  3. 6

  4. 9

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Correct Option: C

An inert gas which is not very soluble in water?

chemistry the periodic table periodic trends in chemical properties alkali metals study of specific groups

  1. $Ne$

  2. $Ar$

  3. $Xe$

  4. $CO _2$

  5. $He$

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Correct Option: E
Explanation:

Helium is an inert gas. Inert gases are not very reactive as their outermost shell is completely filled. $ {He} $ is not very soluble in water.

Thus option $E$ is the correct answer.

Choose the correct answer:

As per the octet rule, noble gases are stable in nature. This is due to the presence of________ electrons in their outermost shell.

chemistry the periodic table periodic trends in chemical properties alkali metals study of specific groups

  1. 8

  2. 18

  3. 6

  4. 2

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Correct Option: A
Explanation:

As per octet rule, noble gases have 8 electrons in their outermost shell. According to octet rule the element which has 8 electron in its valence shell are stable.

X, Y and Z are elements in Period $3$ of the Periodic Table. The results of some experiments carried out with compounds of these elements are shown.


Element Result of adding the oxide of the element to $H _2O(l)$ Result of adding the chloride of the element of $H _2O(l)$ Result of adding the oxide of the element to $HCl(aq)$
X No reaction Hydrolyses Forms chloride salt
Y Forms hydroxide Dissolves Forms chloride salt
Z Forms acid Hydrolyses Hydrolyses


Which statement could be correct?

chemistry patterns and properties of metals periodic trends in chemical properties alkali metals study of specific groups

  1. X is Al and Y is Mg

  2. X is Si and Y is Na

  3. Y is Al and Z is P

  4. Y is Na and Z is Al

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Correct Option: B

In which of the following order of hydration energy correct?

chemistry patterns and properties of metals periodic trends in chemical properties alkali metals study of specific groups

  1. $Li^+ > Na^+ > K^+ > Rb^+ > Cs^+$

  2. $Li^+ < Na^+ < K^+ < Rb^+ < Cs^+$

  3. $Li^+ > Na^+ > K^+ > Cs^+ > Rb^+$

  4. $Li^+ < Na^+ < K^+ < Cs^+ < Rb^+$

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Correct Option: A
Explanation:

Hydration decreases with a decrement in charge density of an ion

Metal which is soft and floats on water is _______ .
chemistry patterns and properties of metals periodic trends in chemical properties alkali metals study of specific groups

  1. aluminium

  2. copper

  3. lead

  4. potassium

  5. iron

  6. lithium

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Correct Option: F
Explanation:

Lithium is lightest elemental metal nearly half as dense as water, so it floats on the surface and ultimately disappears, giving off hydrogen gas and forming a colourless solution of lithium hydroxide.


Hence, the correct option is $\text{F}$

Sodium reacts with water more vigorously than lithium because it :

chemistry patterns and properties of metals periodic trends in chemical properties alkali metals study of specific groups

  1. has higher atomic weight.

  2. is a metal.

  3. is more electropositive.

  4. more electronegative.

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Correct Option: C
Explanation:

Sodium reacts with water more vigorously than lithium its more electropositive and will give electrons easily.
Hence option C is correct.

Which of the following does not react with water?

chemistry patterns and properties of metals periodic trends in chemical properties alkali metals study of specific groups

  1. Sodium ions

  2. Sodium atoms

  3. Potassium ions

  4. Both $A$ and $C$

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Correct Option: D
Explanation:

Sodium ions and potassium ions do not react with water.
The main reason is that have already lost that electron and are therefore much more stable. They don't tend to lose another electron, and they certainly don't try to get that lost electron back, so there's no tendency for them to react.

Which of the following element reacts violently when kept under water?

chemistry patterns and properties of metals periodic trends in chemical properties alkali metals study of specific groups

  1. $Na$

  2. $Fe$

  3. $Cu$

  4. $Au$

  5. $Ne$

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Correct Option: A
Explanation:

Answer (A)

Sodium reacts violently with water to give $H _2$ gas
$2Na+2H _2O\rightarrow2NaOH+H _2$