Borax

Q. Allyl cyanide; $C_3{H}_{5}CN$ has:

1. $8$ sigma bonds, $4$ pi bonds and $4$ non bonding electrons
2. $9$ sigma bonds and $4$ pi bonds
3. $8$ sigma bonds and $5$ pi bonds
4. $9$ sigma bonds, $3$ pi bonds and $1$ lone pairs

Q.

The crystalline form of borax has

1. Tetranuclear $\left[B_4{O}_5\right(OH{)}_4{]}^{2-}$

2. All boron atoms in the same plane

3. Equal number of $s{p}^2$ and $s{p}^3$ hybridized boron atoms

4. One terminal hydroxide per boron atom

Q. how many covalent bonds are there in PROPENE

Q. Colemanite is a mineral of:

1. Ca
2. B
3. Al
4. Ga

Q. A certain metals gives two oxides in first oxide the percentage of oxygen is 22.5 % and in second oxide % of oxygen is36.8 respectively .if the formula of the first oxide is MO then the formula of II oxide will be

Q. Allyl cyanide; $C_3{H}_{5}CN$ has:

1. $9$ sigma bonds and $4$ pi bonds
2. $8$ sigma bonds and $5$ pi bonds
3. $8$ sigma bonds, $4$ pi bonds and $4$ non bonding electrons
4. $9$ sigma bonds, $3$ pi bonds and $1$ lone pairs

Q. The correct option(s) regarding borax is/are :

1. White crystalline solid
2. More soluble in cold water
3. Less soluble in hot water
4. More soluble in hot water

Q. what is dioxygen?

Q. A and B combinescto form three compound AB AB2 AB3. In 3rd compound 32g of A combined to form 84g B. In 2nd compound 16g of A will combine to form how many grams of B.

Q.

Which of the following compound involves the formation of three centre two electrons bond?

1. Ethane

2. Diborane

3. Propane

4. Silicones

Q. 49. The equivalent weight of metal whose 1 g carbonateon heating gives 0.6 g of metal oxide, is(1) 25 g(2) 30 gn(3) 35 g(4) 40 g

Q. Two metallic oxides contain 27.6% and 30% oxygen respectively. If the formula of the first oxide is X3O4 that of the second will be?

Q. The ionization constant of benzoic acid is $6.46\times {10}^{-5}$ and $K_{sp}$ for silver benzoate is $2.5\times {10}^{-13}$. How many times is silver benzoate more soluble in a buffer of $pH3.19$ compared to its solubility in pure water?

Q. Borax is used as a cleansing agent because on dissolving in water, it gives:

1. Alkaline solution
2. Acidic solution
3. Bleaching solution
4. Neutral solution.

Q.

When Borax is dissolved in water

1. is formed

2. and are formed

3. is formed

4. is formed only

Q. Which of the following cations cannot give borax bead test?

1. $C{r}^{3+}$
2. $C{o}^{2+}$
3. $M{n}^{2+}$
4. $A{g}^{+}$

Q. What is the significance of maximum buffer capacity in the case of weak acid strong base conductometric titration?

Q. Two oxides of Metal contain 27.6% and 30 % oxygen respectively. If the formula of first oxide is M, Othen tormula of second oxide isc10.(C) MO3(B) M, O(D) MO(A) MO

Q.

Borax is used as a cleansing agent because on dissolving in water it gives

1. Acidic solution

2. Alkaline solution

3. Bleaching solution

4. Neutral solution

Q. 16. What is the empirical formula of vanadiam oxide if 2.74 g of metal oxide contains 1.53 g of metal? A V2O3 B VO C V2O5 D V2O7

Q. Match the Column-I with Column-II. Choose the correct option among the following
Column – I Column – II
(A) Borax (p) $s{p}^3$ hybridization of B
(B) $B{F}_3$ (q) $s{p}^2$ hybridization of B
(C) Diborane (r) Triangular unit
(D) Boric acid (s) Tetrahedral unit

1. A-(p, q, r, s), B-(q, r), C-(p, s), D-(q, r)
   
2. A-(r, s), B-(p, q), C-(p, q, r, s), D-(s)
   )
3. A-(p, q, ), B-(q, r), C-(p, s), D-(q, r)
   
4. (r, s), B-(p, q), C-(s), D-(p, r)

Q.

The types of σ bonds present in Benzene tri ozanide

1. 3

2. 4

3. 5

4. 2

Q. On acidification of aqueous borax solution, it gives white flakes. This is due to formation of

1. $B(OH{)}_3$
2. $B_2{O}_3$
3. $B_2{H}_6$
4. $NaB{O}_2$

Q. Pcl4- == hybridisation

Q.

$\begin{array}{cc}\text{List I}& \text{List II}\\ \text{A.}B{i}^{3+}⟶(BiO{)}^{+}& \text{p. Heat}\\ \text{B.}[Al{O}_2{]}^{-}⟶Al(OH{)}_3& \text{q. Hydrolysis}\\ \text{C.}Si{O}_4^{4-}⟶S{i}_2{O}_7^{6-}& \text{r. Acidification}\\ \text{D.}\left(B_4{O}_7^{2-}\right)⟶B(OH{)}_3& \text{s. dilution by water}\end{array}$

1. A – q B – r C – p D –q, r

2. A – r B – q C – p D –q, r

3. A – q, r B – q C – q D –q

4. None of the above

Q. Which coloured bead is formed in borax bead test to detect $C{u}^{2+}$?

1. Blue bead
2. Red bead
3. Green bead
4. Black bead

Q.

$C{a}_2{B}_6{O}_{11}+N{a}_{2}C{O}_3\stackrel{Fused}{\to }\left(A\right)+\left(B\right)+CaC{O}_3\left(A\right)+C{O}_2\to \left(B\right)+N{a}_{2}C{O}_3\text{Solution}\left(B\right)+Conc.HCI\to NaCI+Acid\downarrow H_{2}O\left(C\right)\underset{heated}{\overset{Strongly}{\to }}\left(D\right)\text{Acid}\left(C\right)\left(D\right)+CuS{O}_4\underset{inflame}{\overset{Heated}{\to }}\text{Blue coloured}\left(E\right)\text{compound}\text{compound (E) is -}$

1. Cu2O

2. CuS

3. CuSO3

4. Cu(BO2)2

Q. The mineral colemanite is finely powdered and boiled with sodium carbonate solution. The precipitate of $CaC{O}_3$ and other two products X and Y are formed. On passing a current of $C{O}_2,Y$ produces X. Which of the following statement is correct about X?

1. Oxidation state of boron in compound X is +1
2. It is used in bead test
3. It is a black crystaline solid
4. None of these

Q. ntTwo metallic oxides contains 27.6percent and 30 percent oxygen respectively .If the formula of the first oxide is X3O4, that of the second will ben ntn

Q. Number of H-C-H bond in methane?? Shouldnt it be 2 only??