Ca2B6O11+Na2CO3Fused−−−→(A)+(B)+CaCO3(A)+CO2→(B)+Na2CO3Solution(B)+Conc.HCI→NaCI+Acid ↓H2O(C)Strongly−−−−−→heated (D) Acid(C)(D)+CuSO4Heated−−−−−→inflameBlue coloured(E) compoundcompound (E) is -
When Borax is dissolved in water
is formed only
and are formed
Borax is converted into crystalline boron by the following steps.
X & Y are respectively
Aqueous solution of borax reacts with two mol of acids. This is because of -
Formation of 2 mol of only
Formation of 1 mol each of and
Formation of 1mol of only
Formation of 2 mol each of and , of which only reacts with acid
Borax is actually made of two tetrahedra and two triangular units joined together and should be written as: Na2[B4O5(OH)4]·8H2O
The correct statement/s about borax is/are:
a. Each boron atom has four B-O bonds
b. Each boron atom has three B-O bonds
c. Two boron atoms have four B-O bonds while other two have three B-O bonds
d. Each boron atom has one -OH groups
The crystalline form of borax has
All boron atoms in the same plane
Equal number of sp2 and sp3 hybridized boron atoms
One terminal hydroxide per boron atom
List IList IIA. Bi3+⟶(BiO)+p. HeatB. [AlO2]−⟶Al(OH)3q. HydrolysisC. SiO4−4⟶Si2O6−7r. AcidificationD. (B4O2−7)⟶B(OH)3s. dilution by water
A – q B – r C – p D –q, r
A – r B – q C – p D –q, r
A – q, r B – q C – q D –q
None of the above
- It is a useful primary standard for titrating against acids.
- One mole of borax contains 4 B−O−B bonds.
- An aqueous solution of borax can be used as a buffer.
- It is made up of two triangular BO3 units and two tetrahedral BO4 units
Assertion (A) : NaBO3/OH− can be used for oxidation of Cr3+ to Cr6+.
Reason (R) : In alkaline solution NaBO3 produces H2O2.
- (A) is correct; (R) is correct and (R) correctly explains (A).
- (A) is correct; (R) is correct and (R) doesn't explain (A) correctly.
- (A) is correct; (R) is incorrect.
- (A) is incorrect; (R) is correct.