How many aldol condensation products can be obtained when two aldehydes, both with a-hydrogen atoms undergo reaction?

Match List-I with List-II

List-I	List-II
(A) Tetracarbonylnickel(0)	\((I)\) \(\left[ CoCl _2(e n)_2\right]^{+}\)
(B) Tetraammineaquachloridocobalt (III)	chloride \((I I) K _2\left[ Zn ( OH )_4\right]\)
(C) Potassium tetrahydroxidozincate(II)	\((III)\) \(\left[ Co \left( NH _3\right)_4\left( H _2 O \right) Cl \right] Cl _2\)
(D) Dichloridobis(ethane-1,2-diamine)cobalt(III)	\((IV)\) \(\left[ Ni ( CO )_4\right]\)

Choose the correct answer from the options given below:

Elements of group-15, 16 and 17 form compounds with hydrogen with general formula MH3, H 2 M and HX (called hydrogen halides). Stability of these hydrides, along with M-H bond strength and basic nature decreases down the group. Boiling point of these hydrides mainly depends on the strength of their inter molecular forces.
Bond angle (HMH) among hydrides of group-16 decreases down the group because:

p-block elements are placed in groups 13 to 18 of the periodic table. Group 15 is nitrogen family.
Nitrogen makes various compounds like \(NH _3, HNO _3, N_2 O , NO _2\) etc. Phosphorus exists in the form of white and red phosphorus. White phosphorus glows in dark. \(PH _3\) gas is used as smoke screen. Group 16 is called oxygen family. Dry air contains \(21% O_2\) gas by volume. Combined sulphur exists as sulphates such as gypsum, epsome salt, baryte etc. The allotropic forms of sulphur are Rhombic and monoclinic sulphur. \(S_2\) is paramagnetic like \(O_2\) and it stable at high temperature. Group 17 is Halogen family. \(F _2\) is highly reactive, \(Cl _2\) is greenish yellow gas. Both \(SO _2\) and \(Cl _2\) are used for bleaching. Group 18 is Noble gas family but some noble gases also form compounds.
Complete hydrolysis of \(XeF _6\) gives HF and \(XeO _3\) as main products. The permanent bleaching effect is caused by :

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 \(\mathrm{V}, \mathrm{Mn}, \mathrm{Cu}\) and Zn is \(23,25,29\) and 30 respectively. Which of them shows a positive value for the standard electrode potential \(E^{\circ}\left(M^{2+} / M\right)\) ?

"The amines which are soluble in water
(A) Methanamine
(B) Ethanamine
(C) Propanamine
(D) Benzylamine
Choose the correct answer from the options given below:"

Which alloy is used for making bullets and lighter flints?

The point of local maxima of the function \(f(x)=(x-2)^5(x+2)^2\) is

The minimum value of \(a x+b y\), where \(x y=c^2\) and \(a, b, c\) are positive, is:

The refractive index of water is \( \left(\frac{4}{3}\right) \) and that of glass is \( \left(\frac{3}{2}\right) \).
If the speed of light in glass is \( 2 \times 10^8 \text{ m/s} \), the speed of light in water will be:

Which one is a water-soluble protein?

Match List-I with List-II

List-I (Integral)	List-II (Value)
(A) \(\int_{-1}^1(|x|+1) d x\)	(I) 0
(B) \(\int_{-2}^2|x+1| d x\)	(II) 2
(C) \(\int_{-1}^1 3|x|^2 d x\)	(III) 5
(D) \(\int_{-1}^1 x|x| d x\)	(IV) 3

Choose the Correct answer from the options given below :

In a photoelectric effect, the number of photo electrons emitted per second is directly proportional to