Tag: hydrogen

Questions Related to hydrogen

Ionic hydrides are usually:

hydrides hydrogen and its compounds hydrogen chemistry

  1. good electrical conductors when solid

  2. easily reduced

  3. good reducing agents

  4. liquid at room temperature

Show answer
Correct Option: C
Explanation:

Ionic hydrides are usually good reducing agents. 

$2CO+NaH \rightarrow HCOONa+C$ 
$PbSO _4+2CaH _2 \rightarrow PbS + 2Ca(OH) _2$ 
$Fe _3O _4 + NaH \rightarrow 3Fe +4 NaOH$

The stability of hydrogen halides is in the order of:

hydrides hydrogen and its compounds hydrogen chemistry

  1. $HF>HI>HBr>HCl$

  2. $HI>HBr>HCl>HF$

  3. $HF>HCl>HBr>HI$

  4. $HCl>HBr>HI>HF$

Show answer
Correct Option: C
Explanation:

Due to large difference in electronegativity of upper halogens and hydrogen, they are more stable than lower hydrogen halide.
$\therefore $ Stability order: $HF>HCl>HBr>HI$.

Which of the following hydride is 'electron-precise' type?

hydrides hydrogen and its compounds hydrogen chemistry

  1. $HF$

  2. $H _2O$

  3. $SiH _4$

  4. $PH _3$

Show answer
Correct Option: C
Explanation:

Hydrides of carbon family known as electron Precise.

Hydorgen forms binary compounds called hybrides with several elements in the periodic table.Regarding these hydrides the wrong statement 

hydrides hydrogen and its compounds hydrogen chemistry

  1. Among lanthanoids europioum and ytterbium form ionic hydrides

  2. Density of ionic hydrides is less while the density of interstitial hydrides is more than the metals from which they are formed

  3. The rate of reaction of alkali metals towards hydrogen decreases from lithium to ceasium

  4. Hydrogen gas can be purified by the phenomenon of Occlusion of hydrogen by palladium

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Correct Option: A

The hydride ion, $H^{-}$ is a stronger base than its hydroxide ion $OH^{-}$. Which of the following reactions will occur, if sodium hydride $(NaH)$ is dissolved in water?

hydrides hydrogen and its compounds hydrogen chemistry

  1. $H^{-} _{\left ( aq \right )}+H _{2}O\rightarrow H _{3}O^{-}$

  2. $H^{-} _{\left ( aq \right )}+H _{2}O _{\left ( l \right )}\rightarrow OH^{-}+H _{2}$

  3. $H^{-}+H _{2}O _{(l)}\rightarrow\ no\ reaction$

  4. $None\ of\ the\ above$

Show answer
Correct Option: B
Explanation:

Sodium hydride $(NaH)$ react with water to form hydrogen gas and the sodium hydroxide $(NaOH)$.
$NaH+H _2O\rightarrow H _2+NaOH$
i.e., $Na^+, H^-$ and $H^+, OH^- $ give rise to $H _2$ and $NaOH$. So, it is similar to option B.

According to recent views, which is the current representation of hydrated proton in aqueous solution?

hydrides hydrogen and its compounds hydrogen chemistry

  1. $H^{+}$

  2. $H _{9}O _{5}^{+}$

  3. $H _{9}O _{4}^{+}$

  4. $H _{3}O^+$

Show answer
Correct Option: D
Explanation:

The hydrated proton is represented as $H _3O^+$. Hence, the correct option is $D$.

Which of the following metals directly combine with hydrogen gas to give a hydride? 

hydrides hydrogen and its compounds hydrogen chemistry

  1. Au

  2. Ni

  3. Ca

  4. Cu

Show answer
Correct Option: C
Explanation:

Amongst, $Au$, $Ni$, $Ca$ and $Cu$, $Ca$ is the most reactive metal. So it easily combines with $H _2$ to form hydride while the other metals do not combine directly.


The reaction can be given as:-
$Ca+H _2\longrightarrow CaH _2$

What is the trend of boiling points of hydrides of N, O, and F?

hydrides hydrogen and its compounds hydrogen chemistry

  1. Due to lower molecular masses $NH _{3}, H _{2}O$ and HF have lower boiling points than those of the subsequent group member hydrides

  2. Due to higher electronegativity of N, O and F; $NH _{3}, H _{2}O$ and HF show hydrogen bonding and hence higher boiling points than the hydrides of their subsequent group members.

  3. There is no regular trend in the boiling points of hydrides

  4. Due to higher oxidation states of N, O and F, the boiling points of $NH _{3}, H _{2}O$ and HF are higher than the hydrides of their subsequent group members.

Show answer
Correct Option: B
Explanation:

The boiling point increases with increase in molecular masses. But in the case of $N, O$ and $F$ they show the higher boiling point in molecules. 

This is due to the higher electronegativity of $N, O$ and $F$ which leads to hydrogen bonding in $NH _3, H _2O$ and $HF$ due to which the boiling point of these increases & is higher than the hydrides of their subsequent group members.

Which of the following hydrides is electron-precise hydride?

hydrides hydrogen and its compounds hydrogen chemistry

  1. $B _2H _6$

  2. $NH _3$

  3. $H _2O$

  4. $CH _4$

Show answer
Correct Option: D
Explanation:
Methane $CH _4$ is electron-precise hydride.
Diborane $B _2H _6$ is electron-deficient hydride
Ammonia $NH _3$ and water $H _2O$ are electron-rich hydrides.

Elements of group 14 form electron-precise (having required number of electrons to write the Lewis structure ) form precise hydrides.

Non-stoichiometric hydrides are produced by:

hydrides hydrogen and its compounds hydrogen chemistry

  1. palladium, vanadium

  2. manganese, lithium

  3. nitrogen, filorine

  4. carbon, nockel

Show answer
Correct Option: A
Explanation:

The hydrogen deficient compounds formed by the reaction of $d-block$ and $f-block$ elements with dihydrogen are called Non-stoichiometric compounds. 

The d-block and f-block element form non-stoichiometric hydride because of the vacant d- and f-orbitals along with the small size.
Their elemental composition proportions cannot be represented in integers. They disobey the law of constant composition. Among the elements given, only vanadium and palladium form non-stoichiometric hydrides.


Answer: (A) palladium, vanadium