Preparation and Properties of Beryllium Hydride

Q. In context with beryllium, which one of the following statements is incorrect ?

1. Its salts rarely hydrolyze.
2. Its hydride is electron-deficient and polymeric.
3. It is rendered passive by nitric acid.
4. It forms $B{e}_{2}C$.

Q. Which of the following statements are correct?
(A) Both $LiCl$ and $MgC{l}_2$ are soluble in ethanol.
(B) The oxides $L{i}_{2}O$ and $MgO$ combine with excess of oxygen to give superoxide.
(C) $LiF$ is less soluble in water than other alkali metal fluorides.
(D) $L{i}_{2}O$ is more soluble in water than other alkali metal oxides.
Choose the most appropriate answer from the options given below:

1. (A), (C) and (D) only
2. (B) and (C) only
3. (A) and (C) only
4. (A) and (D) only

Q. $Be{F}_2$ is formed by decomposition of:

1. $BeC{l}_2$
2. $(N{H}_4{)}_{2}Be{F}_4$
3. None of the above
4. $BeC{O}_3$

Q.

Classify each of the following solids as ionic, metallic, molecular, network (covalent) or amorphous.

(i) Tetra phosphorus decoxide (P₄O₁₀) (vii) Graphite

(ii) Ammonium phosphate (NH₄)₃PO₄ (viii) Brass

(iii) SiC (ix) Rb

(iv) I₂ (x) LiBr

(v) P₄ (xi) Si

Q.

In the following question, a statement fo Assertion (A) followed by a statement fo Reason (R ) is given. Choose the correct option out of the choices given below in each question
Assertion (A) Beryllium carbonate is kept in the atmosphere fo carbon dioxide.
Reason (R) Beryllium carbonate is unstable and decomposes to give beryllium oxide and carbon dioxide.
(a) Both A and R are correct and R is the correct explanation of A
(b) Both A and R are correct but R is not the correct explanation of A
(c) Both A and R are not correct
(d) A is not correct But R is correct

Q.

Choose the correct statements from the following . ?
(a) Beryllium is not readily attacked by acids because of the presence of an oxide film on the surface of the metal
(b) beryllium stable is readily soluble in water as the greater hydration enthalpy of $Be2+$ very the lattice enthalpy factor
(c) Beryllium exhibits coordination number more than four
(d) Beryllium oxide is purely acidic in nature

Q. Beryllium carbide reacts with water to give

1. acetylene
2. Methane
3. ethane
4. ethylene

Q. $Be{F}_2$ is formed by the decomposition of:

1. $BeC{l}_2$
2. $(N{H}_4{)}_{2}Be{F}_4$
3. $BeC{O}_3$
4. None of the above

Q. Choose the correct statement(s) regarding Beryllium:

1. Cu-Be alloys are used in the preparation of high strength springs.
2. Metallic beryllium is used for making windows of X-ray tubes.
3. $BeC{O}_3$ is used as an ingredient in toothpaste.
4. It is used in the manufacture of alloys.

Q. When chloro - bridged dimeric form of beryllium chloride is heated at 1200${}^{\circ }$C, then in the product is formed, hybridization of central atom & shape of molecule is

1. sp² , angular

2. sp, linear

3. sp³, pyramidal

4. sp², triangular shape

Q.

Non-stoichiometric cuprous oxide, Cu₂O can be prepared in laboratory. In this oxide, copper to oxygen ratio is slightly less than 2:1. Can you account for the fact that this substance is a p-type semiconductor?

Q. What are intrinsic semiconductors ? Given an example.

Q. The total number of bonds in the elemental white phosphorous molecule is

Q. In context with beryllium, which one of the following statements is incorrect ?

1. It is rendered passive by nitric acid
2. It forms $B{e}_{2}C$
3. Its hydride is electron-deficient and polymeric
4. Its salts rarely hydrolyse

Q. Assertion :Both $L{i}_{2}C{O}_3$ and $N{a}_{2}C{O}_3$ will turn lime water milky on heating. Reason: $L{i}_{2}C{O}_3$ on heating gives $L{i}_{2}O$ and $C{O}_2$ on heating.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is incorrect but Reason is correct
4. Both Assertion and Reason are incorrect

Q. The structures of beryllium chloride in the solid state and vapour phase, respectively are

Q. The charge/size ratio of a cation determines its polarising power. Which one of the following sequences represents the increasing order of the polarising power of cationic species?

1. $M{g}^{2+}<B{e}^{2+}<K^{+}<C{a}^{2+}$
2. $B{e}^{2+}<K^{+}<C{a}^{2+}<M{g}^{2+}$
3. $C{a}^{2+}<M{g}^{2+}<B{e}^{2+}<K^{+}$
4. $K^{+}<C{a}^{2+}<M{g}^{2+}<B{e}^{2+}$

Q. $KCl{O}_3\to KCl+O_2$

1. $Mn{O}_2$
2. $FeC{l}_3$
3. $ZnO/CuO$
4. $PdC{l}_2$

Q. Assertion :$A{l}_2{O}_3$ is converted to aluminium by reduction with carbon. Reason: Carbon (graphite) has greater affinity for oxygen than $Al$.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Compare thermal stability of $ZnO,CdO$ and $HgO$.

1. $CdO>ZnO>HgO$
2. $HgO>ZnO>CdO$
3. $ZnO>CdO>HgO$
4. $ZnO>HgO>CdO$

Q. Paragraph:
The trend of metallic properties is not that obvious in group 17. Fluorine is the most electronegative element and has no basic properties. Iodine and Bromine dissolve in oleum and other strong oxidising solvents forming species like $[I_2{]}^{+}$ and $[B{r}_2{]}^{+}$. Many other species like $[I_3{]}^{+}$ and $[B{r}_3{]}^{+}$ have also been prepared.

The shapes of $[I_3{]}^{+}$ and $[I_3{]}^{-}$ respectively are:

1. Linear, bent
2. Bent, bent
3. Linear, linear
4. Bent, linear

Q. Which of the following metal carbides may be called a methanide?

1. $Ca{C}_2$
2. $M{g}_2{C}_3$
3. $A{l}_4{C}_3$
4. $Ba{C}_2$

Q. Acetone can be obtained by the dry distillation of which of the following?

1. Mixture of calcium formate + calcium acetate
2. Calcium formate only
3. Calcium propionate only
4. Calcium acetate only

Q. Which of the following is more stable complex and why? ${\left[Co{\left(N{H}_3\right)}_6\right]}^{3+}$ and ${\left[Co{\left(en\right)}_3\right]}^{3+}$

Q. The element of alkaline earth metal which forms a compound with oxygen which is soluble in water. The element is likely to be:

1. $Ca$
2. $Mg$
3. $Al$
4. none of these

Q. Assertion :Photoelectric effect is easily pronounced by caesium metal. Reason: Photoelectric effect is easily pronounced for the metals with high ionization energy.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Assertion is incorrect but Reason is correct

Q. When chloro - bridged dimeric form of beryllium chloride is heated at 1200${}^{\circ }$C, then in the product is formed, hybridization of central atom & shape of molecule is

1. sp² , angular

2. sp³, pyramidal

3. sp, linear

4. sp², triangular shape

Q. The charge/size ratio of a cation determines its polarizing power. Which one of the following sequences represents the increasing order of the polarizing power of the cationic species, K${}^{+}$, Ca${}^{2+}$, Mg${}^{2+}$, Be${}^{2+}$?

1. Mg${}^{2+}$ < Be${}^{2+}$ < K${}^{+}$ < Ca${}^{2+}$
2. Be${}^{2+}$ < K${}^{+}$ < Ca${}^{2+}$ < Mg${}^{2+}$
3. Ca${}^{2+}$ < Mg${}^{2+}$ < Be${}^{2+}$ < K${}^{+}$
4. K${}^{+}$ < Ca${}^{2+}$ < Mg${}^{2+}$ < Be${}^{2+}$

Q. What happens when ammonia reacts with bromine?

Q. Compound D can be

1. $N{a}_{2}C{r}_2{O}_4$
2. $(N{H}_4{)}_{2}C{r}_2{O}_7$
3. $MnC{l}_2$
4. $N{a}_{2}C{r}_2{O}_7$