According to the electrochemical series, which of the following statements is incorrect?

Calculate the mass of urea \((NH_2CONH_2)\) required to prepare \(2.5\ kg\) of a \(0.25\ molal\) aqueous solution.

What is the IUPAC name of m-cresol?

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Haloalkanes undergo nucelophilic substitution reactions owing to the polarity of C X bond. The nucleophile reacts with the haloalkane on the carbon possessing a partial positive charge holding the halogen atom. The halogen atom \(X\) is replaced by a nucleophile. Depending on the kinetics and mode of bond breaking, the mechanism can be either SN1 or SN2 reaction. The rate of SN1 reaction is governed by the stability of carbocation and in SN2 reaction, the rate of reaction is governed by steric factor. Chirality is the main factor in both SN1and SN2. In SN1 reaction, the chirality of alkyl halide is accompanied by racemization of the product, while in SN2 reaction, the product is characterized by inversion of configuration. The structure of alkyl halide and the nature of the solvent also governs the mechanism of the substitution.
What is chiral carbon ?

Match List I with List II

LIST I	LIST II
A. Mg in solid state	I. p-type Semiconductor
B. \(MgCl _2\) in molten state	II. n-type Semiconductor
C. Silicon with phosphorus	III. Electrolytic Conductor
D. Germanium with boron	IV. Electronic Conductor

Choose the correct answer from the options given below:

Which of the following compound(s) on being warmed with \(I_2\) solution and NaOH , will give Iodoform?
A. \(CH _3 CH _2 OH\)
B. \(CH _3 COCH _3\)
C. \(H _3 C - CHOH - CH _3\)
D. \(CH _3 OH\)
Choose the correct option

20 g of binary electrolyte (Molecular mass = 100) are dissolved in 500 g of water. The freezing point of the solution is -0.74°C and \(K_f \) is 1.86 K kg mol⁻¹. The degree of ionisation of the electrolyte is:

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An overwhelming majority (99 per cent) of animals and nearly all plants cannot maintain a constant internal environment. Their body temperature changes with the ambient temperature. In aquatic animals, the osmotic concentration of the body fluids change with that of the ambient air and water osmotic concentration. These animals and plants are simply conformers. Considering the benefits of a constant internal environment to the organism, we must ask why these conformers had not evolved to become regulators. Recall the human analogy we used above; much as they like, how many people can really afford an air conditioner? Many simply 'sweat it out' and resign themselves to suboptimal performance in hot summer months. Very small animals are rarely found in polar regions. During the course of evolution, the costs and benefits of maintainin a constant internal environment are taken into consideration. Some species have evolved the ability to regulate, but only over a limited range of environmental conditions, beyond which they simply conform.
If the stressful external conditions are localised or remain only for a short duration, the organism has five other alternatives for survival.
Identify the set of aquatic animals whose osmotic concentration is not constant.

Which of the following reactions are given by Phenols?
(A) Nitration
(B) Halogenation
(C) Oxidation
(D) Acetylation
Choose the correct answer from the options given above:

Electromagnetic waves carry

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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?

A gaussian surface encloses three point charges \( q_1 = -14 \text{ nC}, q_2 = 78.85 \text{ nC} \) and \( q_3 = -56 \text{ nC} \). The electric flux for the gaussian surface due to these charges is

The amount of radioactive substance left after \(75\) hours,
when \(100\) g of it is taken initially, will be:
(Half-life of the radioactive substance is \(15\) hours)