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 :
List I Nuclear reactor components | List II substance |
1. Moderator | A.Uranium |
2. Control rods | B.Graphite |
3. Fuel rods | C.Boron |
4.Coolant | D.Lead |
E.Sodium |
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
B.
1-B, 2-C, 3-A, 4-E
Moderntor: Graphite
Contrui rods : Boron
Fuel rods : Uranium
Coolant : Lead
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+