Tag: study of the first element - hydrogen

Questions Related to study of the first element - hydrogen

____________ element has one electron in its outermost shell and attains duplet configuration after one more electron and attains stability.

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. Hydrogen

  2. Fluorine

  3. Helium

  4. Berrylium

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Correct Option: A
Explanation:

Hydrogen has one electron in its outermost shell and attains duplet configuration after one more electron and attains stability.

Hydrogen readily combines with which of these elements?

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. Na

  2. K

  3. Ca

  4. Zn

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Correct Option: A,B,C,D

Hydrogen occupies a unique position in Modern Periodic Table.

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. True

  2. False

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Correct Option: A
Explanation:

Hydrogen has electron configuration of $ 1s^{1}$.To become stable it can either accept to get helium configuration that is a stable configuration or it can even donate one electron. Hence it is very confusing where to place either in the metals group as it donates or in nonmetal group as it accepts an electron. Hence it occupies a unique position in the periodic table.

At the temperature of liquefaction of air, the ratio of ortho and para hydrogen is:

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. 1:1

  2. 1:3

  3. 3:1

  4. 3:2

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Correct Option: A

Hydrogen is mainly found in the combined state like in water and not the free state.

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. True

  2. False

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Correct Option: A
Explanation:

The earths crust contains nearly 1% hydrogen by weight. In free state($H _2$), it occurs only in traces in the atmosphere. It is mainly found in the combined state and not the free state. Important sources are water, acids, organic matter etc.

The present position of hydrogen in the modern periodic table completely justifiable.

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. True

  2. False

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Correct Option: B
Explanation:

Hydrogen has an electronic configuration of $1s^1$. So, it can accept one electron to complete its' outermost orbital which resembles to group $17$ of the periodic table. 

Also, it has only one electron in the outermost orbit which is shown by the elements in group 1. Therefore, the present position of hydrogen in the modern periodic table is not completely justified.
So the answer is False.

Hydrogen resembles halogens in many respects for which several factors are responsible. Of the following factors which one is the most important in this respect?

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. Its tendency to lose an electron to form a cation

  2. It tendency to gain a single electron in its valence shell to attain stable electronic configuration

  3. Its low negative electron gain enthalpy value

  4. Its small size

Show answer
Correct Option: B
Explanation:
Hydrogen resembles halogens as it has similar tendency to gain a single electron to attain stable noble gas configuration. The electronic configuration of hydrogen is $1s^1$. It needs one more electron to attain stable electronic configuration of hellium, a noble gas. The electronic configuration of halogen is $ns^2np^5$. It needs one more electron to attain stable electronic configuration of a noble gas.

Which of the following properties of hydrogen is incorrect?

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. Like halogens, hydrogen exists as a diatomic gas

  2. Like halogens, hydrogen exhibits - 1 oxidation state in its compounds with metals

  3. Like halogens, hydrogen is liberated at cathode

  4. The ionization energy of hydrogen is quite close to halogens

Show answer
Correct Option: C
Explanation:
Like halogens, hydrogen is liberated at anode, e.g. 
2NaH $\rightarrow 2Na + H _{2} $ (at anode
2NaCl $\rightarrow  2Na + cl _{2}$ (at anode)

The order of reactivity of halogens towards hydrogen is:

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. $F _{2} > Cl _{2} > Br _{2} > I _{2}$

  2. $I _{2} > Br _{2} > Cl _{2} > F _{2}$

  3. $Cl _{2} > Br _{2} > I _{2} > F _{2}$

  4. $Br _{2} > Cl _{2} > F _{2} > I _{2}$

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Correct Option: A

Which of the following statement is correct regarding hydrogen?

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. Hydrogen shows +1 and -1 oxidation states

  2. Hydrogen is never liberated at anode

  3. Hydrogen has same ionisation enthalpy as that of alkali metals

  4. Hydrogen has same electronegativity as of halogens

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Correct Option: A
Explanation:

Hydrogen has +1 oxidation state in compounds with more electronegative elements e.g. $HF$. It has -1 oxidation state in compounds with more electropositive elements like $NaH$. In the above compounds with $Na$ and $F$ show +1 and -1 oxidation state respectively.