H3BO3 on heating up to 373 K yields:
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Solution
Which of the following statement is correct with respect to the property of elements with an increase in atomic number in the carbon family (group 14)?
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Solution
In the carbon family the stability of +2 oxidation state increases with increase in atomic number due to inert pair effect.Therefore SnCl4 is more stable than SnCl2 & PbCl2 is more stable than PbCl4.
Aqueous solution of orthoboric acid can be titrated against sodium hydroxide using phenolphthalein indicator only in presence of
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Solution
It forms a stable cyclic complex with poly hydroxy compounds like c is-glycerol, cathechol, etc. This helps in the release of H+ as H3O+ and, therefore,boric acid acts as a strong acid and hence can be titrated with sodium hydroxide using phenolphthalein.
Which of the following statements about an hydrous aluminium chloride is correct?
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Solution
(A)AlCl3 + 3H2O ⟶ Al(OH)3 + 3HCl↑ (fumes)
(B)It exists as dimer in non-polar solvents like benzene and in vapour state below 400°C.
(C)4Al2O3+ 3S2Cl2 + 9Cl2 ⟶ 8AlCl3+ 6SO2↑
So all options are correct.
Action of concentrated nitric acid (HNO3) on metallic tin produces
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Solution
Action of concentrated nitric acid (HNO3) on metallic tin produces hydrated tin oxide (SnO2. 2H2O) which is also called meta stannic acid Sn + 4HNO3 ⟶ SnO2.H2O + 4NO2 + H2O
Select the correct statements for diborane :
1.Boron is approximately sp3 hybridized
2.B – H – B angle is 180°
3.There are two terminal B – H bonds for each boron atom
4.There are only 12 bonding electrons
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Solution
In the electrolytic extraction of aluminium, cryolite is used
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Solution
Cryolite Na3AlF6 is added(1)to decrease the melting temperature from 2323 K to 1140 K(2)to increase the electrical conductivity of solution.
Which one of the following is a metalloid?
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Solution
Antimony is a metalloid because it has some characters of metals and some of non-metals.
AlCl3 acts as a strong Lewis acid because AlCl3 is:
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Solution
AlCl3 acts as a strong Lewis acid because AlCl3 is an electron deficient compound. Al has three electrons in outer most electron. Through sharing it gets 3 electrons. Still it requires 2 electrons to complete it soctet.
Which of the following is not true about potash alum?
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Solution
KAl(SO4)2.12H2O is a molecular formula of potash alum.