When H2O2 is added to ice cold solution of acidified potassium dichromate in ether and the contents are shaken and allowed to stand
a blue colour is obtained in ether because of formation of CrO5
a blue colour is obtained in ether because of formation of CrO3
a blue colour is obtained in ether because of formation of Cr2(SO4)3
chromyl chloride is formed
500 mL of a sample of water required 19.6 mg of K2Cr2O7 for the oxidation of dissolved organic matter in it in the presence of H2SO4. The COD of water sample is
3.2 ppm
7.2 ppm
6.4 ppm
4.6 ppm
The chemical formulae of X, Y and Z are
X | Y | Z |
CaO | Ca(OH)2 | NaOH |
NaOH | CaO | CaCO3 |
NaOH | Ca(OH)2 | CaCO3 |
Ca(OH)2 | NaOH | CaCO3 |
The catenation tendency of C, Si and Ge is in the order Ge < Si < C. The bond energies (in kJ mol-1) of C-C, Si-Si and Ge-Ge bonds, respectively are
348, 167, 180
348, 180, 167
167, 180, 348
180, 167, 348
B.
348, 180, 167
Catenation tendency decreases with the decrease in M-M bond energy. Thus, bond energies of C-C, Si-Si and Ge-Ge must be 348, 180 and 167 kJ mol-1 respectively.
What is correct about the following structure?
Total stereoisomers = 4
Number of chiral carbons = 1
Number of optical isomers= 2
Number of meso compounds = 2
Number of oxygen atoms shared per Si tetrahedron in
I. two dimensional sheet structured silicates
II. cyclic silicates and
III. single strand chain silicates respectively are
3, 3, 2
3, 2, 2
4, 3, 1
4, 3, 2
KMnO4 reacts with ferrous sulphate according to the following equation,
Mn + 5Fe2+ + 8H- Mn2+ + 2Fe3+ + 4H2O
Here, 10 mL of 0.1M KMnO4 is equivalent to
50 mL of 0.1 M FesO4
20 mL of 0.1 M FesO4
40 mL of 0.1 M FesO4
30 mL of 0.1 M FeSO4
Sodium sulphite is used in preserving squashes and other mildly acidic foods due to
potassium salt has preservative action
potassium metabisulphite prevents oxidation
potassium metabisulphite is not influcenced by acid
sulphur dioxide and sulphurous acid formed, kill bacteria and germs
Ferrous oxide has a cubic structure. The length of edge of the unit cell is 5 Å and the density of the oxide is 4 .0 g cm-3 Then the number of Fe2+ and O2- ions present in each unit cell will be
four Fe2+ and two O2-
four Fe2+ and four O2-
two Fe2+ and four O2-
two Fe2+ and two O2-
Which of the following arrangements correctly represents hexagonal and cubic close packed structure respectively?
ABAB. .. and ACBACB ......
ABCABC....... and ABAB
Both have ABCABC.....arrangement
Both have ABAB.... arrangement