The electronic configuration of Cu(II) is 3d⁹ whereas that of Cu(I) is 3d¹⁰. Which of the following is correct?
(a) Cu(II) is more stable
(b) Cu(II) is less stable
(c) Cu(I) and Cu(II) are equally stable
(d) Stability of Cu(I) and Cu(II) depends on nature of copper salts
(a) Cu(II) is more stable
(b) Cu(II) is less stable
(c) Cu(I) and Cu(II) are equally stable
(d) Stability of Cu(I) and Cu(II) depends on nature of copper salts
(a) Cu(II) is more stable
Explanation : Cu(II) is more stable due to nuclear charge of Cu.
Explanation : Cu(II) is more stable due to nuclear charge of Cu.
Electronic configuration of a transition element X in +3 oxidation state is [Ar]3d⁵. What is its atomic number?
(a) 25
(b) 26
(c) 27
(d) 24
Explain the following :
(i) The enthalpies of atomization of transition metals are quite high.
(ii) The transition metals and many of their compounds act as good catalysts.
Metallic radii of some transition elements are given below. Which of these elements will have highest density?
Suggest reasons for the following features of transition metal chemistry :
(i) The transition metals and their compounds are usually paramagnetic.
(ii) The transition metals exhibit variable oxidation states.
Describe the preparation of potassium permanganate. How does the acidified permanganate solution react with oxalic acid ?
Write the ionic equations for the reactions.
Account for the following :
(i) CuCl₂ is more stable than Cu₂Cl₂.
(ii) Atomic radii of 4d and 5d series elements are nearly same.
(iii) Hydrochloric acid is not used in permanganate titration.
Which of the following is not true about the ionic solids?
(A) Bigger ions form the close packed structure.
(B) Smaller ions occupy either the tetrahedral or the octahedral voids depending upon their size.
(C) Occupation of all the voids is not necessary.
(D) The fraction of octahedral or tetrahedral voids occupied depends upon the radii of the ions occupying the voids.
Stability of hydrides of group 16 elements
a) increases down the group
b) decreases down the group
c) all hydrides are equally stable
d) none of the above
The correct order of the packing efficiency in different types of unit cells is ________.
(A) fcc < bcc < simple cubic
(B) fcc > bcc > simple cubic
(C) fcc < bcc > simple cubic
(D) bcc < fcc = simple cubic
The letter ‘D’ in carbohydrates signifies-
(a) dextrorotatory
(b) configuration
(c) diamagnetic nature
(d) mode of synthesis
Silver crystallises in f.c.c. Lattice. It edge length of the unit cells is 4.07 × \(10^{–8}\) cm density and ism 10.5g \(cm^{–3}\). Calculate the atomic mass of silver.
(A) 144 g/mol
(B) 125 g/mol
(C) 106.6 g/mol
(D) 213 g/mol
Which of the following is true about the value of refractive index of quartz glass?
(A) Same in all directions
(B) Different in different directions
(C) Cannot be measured
(D) Always zero
Interstitial compounds are formed when small atoms are dropped under the curved lattice of metals. Which of the following is not the characteristics property of interstitial compounds?
(A) They have high melting points in to pure metals
(B) They are very hard
(C) They retain metallic Conductivity
(D) They are chemically very reactive