Which transition metal ion is most stable against oxidation to its \(+3\) state?

Which one of the following ligands forms a chelate?

Glucose on reaction with bromine water forms gluconic acid which confirms the presence of:

Which property is observed in an emulsion ?

Read the passage carefully and answer the questions
Nearly all the transition elements display typical metallic properties such as high tensile strength, ductility, malleability, high thermal and electrical conductivity and metallic lustre. The transition metals (with the exception of Zn, Cd and Hg) are very hard and have low volatility. Their melting and boiling points are high. They have high enthalpies of atomization. lons of the same charge in a given series show progressive decrease in radius with increasing atomic number. However, the variation within a series is quite small. The filling of 4f before 5d orbital results in a regular decrease in atomic radii called Lanthanoid contraction which essentially compensates for the expected increase in atomic size with increasing atomic number. The net result of the lanthanoid contraction is that the second and the third d series exhibit similar radii (e.g., Zr 160 pm, Hf 159 pm) and have very similar physical and chemical properties. There is an increase in ionisation enthalpy along each series of the transition elements from left to right. The first ionisation enthalpy, in general, increases, but the magnitude of the increase in the second and third ionisation enthalpies for the successive elements, is much higher along a series. One of the notable features of a transition elements is the great variety of oxidation states these may show in their compounds.
Atomic number of Fe, Co, Ni and Cu are 26, 27, 28 and 29 respectively. Which among them is expected to possess the highest value for the second ionization enthalpy?

Answer the question on basis of passage given below :
P block elements are placed in groups 13 to 18 of the periodic table. Their valence shell electronic configuration is \(ns^2 np^{1-6}\). Group 16 of the p block elements are known as the group of chalcogens having \(ns^2 np^4\) as their general electronic configuration. They exhibit number of oxidation states but the stability of \(- 2\) oxidation state decreases down the group. They are sometimes also known as group of chalcogens as the name is derived from the Greek word for brass and points to the association of sulphur and its congeners with copper. Their ionisation enthalpy decreases down the group. Oxygen shows anomalous behaviour due to its small size and high electronegativity.
Which one is the correct electronic configuration of sulphur?

The reaction which can be used to prepare aryl halides is

In RNA interference (RNAi) the genes are silenced using:

Arrange the following events in correct sequence.
A. Transformation of morula into blastocyst.
B. Fusion of sperm with an ovum
C. Implantation
D. Initiation of mitotic division in zygote and formation of morula
Choose the correct answer from the options given below:

Area of the triangle ABC with vertices \(\left(a, a^2\right),\left(b, b^2\right)\) and \(\left(c, c^2\right)\) is equal to :

In the given equations (Note: equations are not balanced):
\(Zn + Conc. HNO_3 \rightarrow Zn(NO_3)_2 + x + H_2O\)
\(Zn + Dil. HNO_3 \rightarrow Zn(NO_3)_2 + y + H_2O\)
The compounds \(x\) and \(y\) respectively are:

Which of the following is an example of homologous organs?

Let \(\left|\begin{array}{ll}3 & y \\ x & 1\end{array}\right|=\left|\begin{array}{ll}3 & 2 \\ 4 & 1\end{array}\right|\) and \(x, y\) are natural numbers, then the number of solutions for the system is :