The p-Block Elements

2 gm of aluminium is treated separately with excess of dil. H₂SO₄ and excess of NaOH, the ratio of volume of hydrogen evolved is :

• 1 : 1

• 2 : 3

• 1 : 2

• 2 : 1

The main component of glass which gives heat resistance to laboratory glassware is 

• PbO

• MgO

• B₂O₃

• Al₂O₃

The order of acidic strength of boron trihalides is :

• BF₃ < BCl₃< BBr₃ <BI₃

• BI₃ < BBr₃ < BCl₃ < BF₃ 

• BCl₃< BBr₃ <BI₃ < BF₃ 

• BBr₃ <BI₃ < BF₃  < BCl₃ 

Match list I and list II and select the correct answer using the code given below the lists :

• 1-B, 2-A, 3-C, 4-E

• 1-B, 2-C, 3-A, 4-E

• 1-E, 2-B, 3-A, 4-C

• 1-C, 2-D, 3-A, 4-B

Pyrosilicate ion is

• ${\mathrm{SiO}}_2^{2-}$

• ${\mathrm{Si}}_2{\mathrm{O}}_7^{6-}$

• ${\mathrm{SiO}}_4^{2-}$

• ${\mathrm{SiO}}_3^{-}$

In the preparation of amorphous silicon, HF is used to remove

• Mg

• SiO₂

• Si

• None of these

What is the molecular formula of borazole ?

• B₂H₆

• B₆N₆H₆

• B₃N₃H₆

• B₃N₃H₃

The oxidation state shown by silicon when it combines with strongly electropositive metals is

• -2

• -4

• +4

• +2

Which one of the following is correct about stability of the given ions?

• Pb²⁺ > Pb⁴⁺

• Pb⁴⁺ > Pb²⁺

• Si²⁺ > Si⁴⁺

• Sn⁴⁺ > Sn²⁺

Thermite is a mixture of X parts of ferric oxide and Y parts of aluminium powder. X, Y respectively are

• 3, 1

• 3, 2

• 1, 1

• 2, 3