Tag: hydrogen

Quizzes (9) Questions (42)

Questions Related to hydrogen

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

From group 6 only one metal forms hydride. This metal is:

  1. Mo

  2. W

  3. Cr

  4. Co
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The low affinity of the elements of the group $6,7,8$ and $9$ towards hydrogen in their normal oxidation states prevent the formation of hydrides. This is called as hydride gap. 

In the group, $6$, Chromium $(Cr)$ is an exception as it is the only group $6$ element to form a hydride.

Answer: $(Cr)$

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Only one element of ________ forms hydride. 

  1. group 6

  2. group 7

  3. group 8

  4. group 9
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The only element of group $6$ i.e. Chromium $(Cr)$ forms hydride. The other elements do not form hydride due to low affinity towards hydrogen.


Answer: (A) group $6$

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Elements of which of the following group (s) of periodic table do not form hydrides?

  1. Groups 7, 8, 9

  2. Group 13

  3. Groups 15, 16, 17

  4. Group 14
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The elements of the groups $7,8,9$ show low affinity towards hydrogen due to which they lack the tendency to form hydrides.


Answer: (A) Groups $7,8,9$

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Which of the following exists as associated molecules due to hydrogen bonding?

  1. $NH _{3}$
  2. $H _{2}O$
  3. $HF$
  4. $HCl$
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Explanation

Due to good extent of hydrogen bonding (hydrogen bonding is more favoured if the hydrogen is attached to an electronegative atom) in A, B and C options, they exist in chains or in groups attached through hydrogen bonding.

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Match list I with list II. Choose the correct matching codes from the choices given. 
     List I                                                 List II
   (Hydride)                                    (Type of hydride)
A. $BeH _{2}$                        1.  Complex
B.. $AsH _{3}$                       2. Lewis acid
C. $B _{2}H _{6}$                   3. Interstitial
D. $LaH _{3}$                        4. Covalent
E. $LiAlH _{4}$                      5. Intermediate

  1. A-6, B-2, C-4, D-5, E-1

  2. A-6, B-2, C-4, D-3, E-1

  3. A-6, B-4, C-2, D-3, E-15

  4. A-5, B-4, C-2, D-3, E-1
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$A.$ $BeH _2\rightarrow$ Intermediate

$B.$ $AsH _3\rightarrow$ Covalent
$C.$ $B _2H _6\rightarrow$ Lewis acid
$D.$ $LaH _3\rightarrow$ Interstitial
$E.$ $LiAlH _4\rightarrow$ Complex

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Match the column I with column II and mark the appropriate choice.

column I column II
A NaH i Interstitial hydride 
B $CH _{4}$ ii Molecular hydride
C $VH _{0.56}$ iii Ionic hydride 
D $B _{2}H _{6}$ iv  Electron-deficient hydride 
  1. $(A)\rightarrow (iii), (B)\rightarrow (iv), (C)\rightarrow (ii) (D)\rightarrow (i)$
  2. $(A)\rightarrow (ii), (B)\rightarrow (iv), (C)\rightarrow (iii) (D)\rightarrow (i)$
  3. $(A)\rightarrow (i), (B)\rightarrow (ii), (C)\rightarrow (iv) (D)\rightarrow (iii)$
  4. $(A)\rightarrow (iii), (B)\rightarrow (ii), (C)\rightarrow (i) (D)\rightarrow (iv)$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
NaH is an ionic compound and is made of sodium cations $\left ( Na^{+} \right )$ and hydride anions $\left ( H^{-} \right )$. It has the octahedral crystal structure with each sodium ion surrounded by six hydride ions.

$CH _{4}$ forms molecular or covalent hydrides. These are mainly formed by p - block elements and some s - block elements.

The third compound has an oxidation number of hydrogen which is zero. So it belongs to Interstitial hydride.

In $B _{2}H _{6}$ the Boron atom is surrounded by 6 electrons, so it is electron deficient due to its incomplete octet.

The correct option is D.
Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Correct order of ionic character is:

  1. $CaH _2 < BaH _2 < CH _4$
  2. $CH _4 < CaH _2 < BaH _2$
  3. $CH _4 < BaH _2 < CaH _2$
  4. $BaH _2< CaH _2 < CH _4$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ionic character depends on the electronegativity difference between the bonded atoms. CH4 is a covalent molecule with small electronegativity difference between C and H. Among ionic hydrides, CaH2 and BaH2, barium is larger and more electropositive than calcium, making Ba-H bond more ionic than Ca-H bond. Thus, the correct increasing order of ionic character is CH4 < CaH2 < BaH2.

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Ionic hydride among following is 

  1. $BeH _2$
  2. $NH _2$
  3. $CaH _2$
  4. $CuH _2$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

CaH2 is a classic example of an ionic (saline) hydride formed by an alkaline earth metal. BeH2 is covalent due to high charge density, and NH2 is not a standard binary hydride (NH3 is).

Multiple choice hydrides hydrogen and its compounds hydrogen chemistry

Among $CaH _2, NH _3, NaH$ and $B _2H _6$, which are covalent hydrides?

  1. $NH _3$ and $B _2H _6$
  2. $NaH$ and $CaH _2$
  3. $NaH$ and $ NH _3$
  4. $CaH _2$ and $B _2H _6$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$NH _3$ and $B _2H _6$ are the covalent hydrides and $CaH _2$ and $NaH$ are the ionic hydride.

$N$ and $B$ form covalent hydride as they have high electronegativity and small size.