Why must the reacting molecules have a minimum energy for an effective collision?

Arrange the following electrolytes in the increasing order of van't Hoff factor (i) for complete dissociation of solute.
A. \(\left[ Co \left( NH _3\right)_6\right] Cl _3\)
B. \(MgCl _2\)
C. \(K _4\left[ Fe ( CN )_6\right]\)
D. KCl
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With reference to Arrhenius equation \(k=A e^{-E_a / R T}\)

Answer the question on basis of passage given below :
A ketone \([ A ]\) which undergoes haloform reaction gives compound \([ B ]\) on reduction. Compound
\([B]\) on heating with sulphuric acid gives compound \([C]\) which forms monozonide \([D]\). The compound \([D]\) on hydrolysis in the presence of zinc dust gives compound \([E]\). Compound \([E]\)
on oxidation gives \(C _2 H _4 O _2\) [F]
Identify Compound [A]

Carbonyl carbon in acetone is \(\mathrm{sp}^2\) hybridized. The C-O-C bond angle and the geometry of acetone is.......

Match List - I with List - II

List - I (Cell Type)	List - II (Characteristic/Reaction)
A. Fuel Cell	I. Rechargeable
B. Mercury Cell	II. Reaction at anode, \(\text{Zn} \rightarrow \text{Zn}^{2+} + 2\text{e}^{-}\)
C. Leclanche Cell	III. Cell reaction \(2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}\)
D. Ni-Cd Cell	IV. Gives steady potential

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Match List I with List II

LIST I	LIST II
A. Gatterman-Koch reaction	I. Diphenyl
B. Stephens reaction	II. Ethyl amine
C. Hoffmann Bromamide degradation	III. Benzaldehyde
D. Fittig reaction	IV. Acetaldehyde

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Alexander Fleming discovered Penicillin, an antibiotic while working on which bacteria ?

In an electromagnetic wave, the ratio of energy densities of electric and magnetic fields is :

Molecules in solids are held together by dipole - dipole interactions. Identify the polar molecules from the following.
A. Solid \(SO_2\)
B. \(NH_3\)
C. \(Cl_2\)
D. \(HCl\)
E. \(He\)
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Read the passage carefully and answer the Questions
The concentration dependence of the rate of a reaction is called the differential rate equation. It is not always convenient to determine the instantaneous rate, as it is measured by calculating the slope of the tangent at point 't' in the concentration vs time plot. This makes it difficult to determine the rate and hence the order of the reaction. This difficulty is overcome by integrating the differential rate equation. This integrated rate equation gives a direct relation between concentrations at different times and the rate constant. The integrated rate equations are different for the reactions having different reaction orders.
Choose the correct statement regarding kinetics of a chemical reaction.

Read the following passage carefully and answer the given questions.
Biofertilisers
Biofertilisers are organisms that enrich the nutrient quality of the soil and their main sources are bacteria, fungi and cyanobacteria. You have studied about the nodules on the roots of leguminous plants formed by the symbiotic association of Rhizobium. These bacteria can fix atmospheric nitrogen into organic forms. Other bacteria can also fix atmospheric nitrogen while free-living in the soil (examples Azospirillum and Azotobacter). Fungi are also known to form symbiotic associations with plants (mycorrhiza). Many members of the genus Glomus form mycorrhiza. Plants having such associations show other benefits also, such as resistance to root-borne pathogens, tolerance to salinity and drought, and an overall increase in plant growth and development. Cyanobacteria are autotrophic microbes widely distributed in aquatic and terrestrial environments many of which can fix atmospheric nitrogen, e.g. Anabaena, Nostoc, Oscillatoria, etc. In paddy fields, cyanobacteria serve as an important biofertiliser. Blue green algae also add organic matter in to the soil and increase its fertility. Currently, in our country, a number of biofertilisers are available commercially in the market and farmers use these regularly in their fields to replenish soil nutrients and to reduce dependence on chemical fertilisers.
Choose the free living, nitrogen-fixing bacteria from the following.

What is the symbol of technetium element ?