Recent questions tagged sec-b

Complete the following reactions : (i) $P_4 +8SOCl_2 \to \\ (ii)\;I^{-}+O_3+H_2O \to $

asked Nov 15, 2016 by meena.p

2 answers

Consider the decomposition of hydrogen peroxide in alkaline medium which is catalyzed by iodide cons . $2H_2O_2 \qquad \underrightarrow{-OH} \qquad 2H_2O+O_3$ This reaction takes place in two steps as given below Step I:$H_2O_2+I^{-} \to H_2O+I_0^{-}$ (slow) Step II:$H_2O_2+IO^{-} \to H_2O+I^{-}+O_2$ (fast) a) Write the rate law expression and determine the order of reaction w.r.t $H_2O_2$ b) What is the molecularity of each individual step ?

asked Nov 15, 2016 by meena.p

1 answer

Explain giving a suitable reason for each of the following : a)Transition metal and their compounds are generally found to be good catalysts. b) Transition metal and their compounds generally exhibit a para-magnetic behaviour .

asked Nov 11, 2016 by meena.p

1 answer

Give the preparation and uses of PVC

asked Nov 10, 2016 by meena.p

1 answer

Out of C and CO, Which is better reducing agent at $673\;k$

asked Nov 9, 2016 by meena.p

1 answer

Why is an increase in temperature observed on mixing chloroform with acetone ?

asked Nov 9, 2016 by meena.p

1 answer

Ionic solid conduct in the molten state but not in the solid state . Explain

asked Nov 9, 2016 by meena.p

1 answer

What causes Brownian movement in a colloidal solution ?

asked Nov 8, 2016 by meena.p

1 answer

How do you explain the functionality of monomer?

asked Nov 4, 2016 by meena.p

1 answer

Explain giving a reason for each of the following situation : (i) In aqueous medium, HCl is stronger acid than HF (ii) White phosphorus is more reactive than red phosphorous.

asked Nov 4, 2016 by meena.p

1 answer

Calculate the equilibrium constant $K_c$ for the reaction . $3Sn^{4+} +2Cr \to 3Sn^{2+}+2Cr^{3+}$Given $E^0 =0.885\;V$

asked Nov 4, 2016 by meena.p

1 answer

Copper crystallizer into an fcc lattice with edge length $3.61 \times 10^{-8}\;cm$ Show that the calculated density is in agreement with its measured value of $8.92 \;g\;cm^{-3}$

asked Nov 4, 2016 by meena.p

1 answer

Define the following terms in relation to crystalline solids . (i) Unit cell (ii) Coordination number . Give one example in each case

asked Nov 2, 2016 by meena.p

1 answer

Calculate the number of unpaired electrons in the following gaseous ions : $(i)Mn^{3+} (ii) Cr^{3+} (iii) V^{3+} (iv) Ti ^{3+} $ Which one of these is most stable in aqueous solutions ?

asked Nov 1, 2016 by meena.p

1 answer

Identify the anode and cathode in the cell written below :$Cu | Cu^{2+}| |Cl^{-} ||Cl_2, Pt$ write the reduction half reaction and oxidation half reaction of the cell

asked Nov 1, 2016 by meena.p

1 answer

$CCl_4$ and water are immisuble whereas ethanol and water are miscible in all proportions. Correlate this behavior with molecular structure of these compounds.

asked Nov 1, 2016 by meena.p

1 answer

What is meant by disproportionation of an oxidation state ? Give an example

asked Oct 27, 2016 by meena.p

1 answer

How would you obtain (i) Picric acid (2,4,6- trinitrophenol) from phenol (ii) 2- Methyl propene from 2- Methyl propanol ?

asked Oct 26, 2016 by meena.p

1 answer

Predict which of the following will be colourless in aqueous solution ? $Ti^{3+},V^{3+},Sc^{3+},Mn^{2+},Fe^{3+},Co^{2+}$ and $MnO_4^{-}$

asked Oct 26, 2016 by meena.p

1 answer

What type of defect can arises when a solid is heated ? Which physical properly is affected by it and in what way ?

asked Oct 26, 2016 by meena.p

1 answer

Why is drug metabolism a major consideration in drug design ?

asked Oct 25, 2016 by meena.p

1 answer

Do we call metal carbonyls as organometallics ? Why or why not ?

asked Oct 25, 2016 by meena.p

1 answer

Aluminium crystallizes in a cubic - packed structure . Radius of the atom in the metal is $125\;pm$ (i) What is the length of the side of the unit cell ? (ii) How many unit cells are there in $1\;cm^3$ of aluminium ?

asked Oct 25, 2016 by meena.p

1 answer

(a)What changes occurs in the nature of egg protein on boiling ? (b) Name the type of bonding . Which stabilizes $\alpha - helix$ structure in proteins .

asked Oct 21, 2016 by meena.p

1 answer

Out of $H_2O$ and $H_2S$ which one has higher, bond angle ?

asked Oct 21, 2016 by meena.p

1 answer

Explain the role of (a) Cryolite in the electrolytic reduction of alumina . (b) carbon monoxide in the purification of nickel

asked Oct 21, 2016 by meena.p

1 answer

Why does a solution of ethanol and cyclohexane show positive deviation from Raoult's law?

asked Oct 21, 2016 by meena.p

1 answer

A compound is formed by two elements, M and N . The element N forms CCP and atoms of M occupy $\large\frac{1}{3}$ rd of tetrahedral voids . What is the formula of the compound?

asked Oct 21, 2016 by meena.p

1 answer

Sodium crystallizes in a bcc unit cell , calculate the appropriate number of unit cell in $9.2\;g$ of sodium (Atomic mass of Na=23 u)

asked Oct 19, 2016 by meena.p

1 answer

What are antiseptics ?

asked Oct 18, 2016 by meena.p

1 answer

How is the present of $SO_2$ detected ?

asked Oct 18, 2016 by meena.p

1 answer

How do antidepressant drugs counteract feeling of depression ?

asked Oct 17, 2016 by meena.p

1 answer

When a broad cast AM transmitter is $50\%$ modulated its antenna current is $12\;A$ . What would be the carrier current ?

asked Oct 3, 2016 by meena.p

1 answer

The calculate the current drawn by the prime of a transformer which steps down $200\;v$ to $20\;v$ to operate a device of resistance $20 \Omega$ the efficiency of the transformer to be $80\%$

asked Sep 27, 2016 by meena.p

1 answer

A transformer has an efficiency of $80\%$ and works at 100 volt and 4 kw. If the secondary voltage is $240\;volt$ calculate the primary and secondary currents

asked Sep 27, 2016 by meena.p

1 answer

1 Mw power is to be delivered from a power station to a town $10\;km$ away. One uses a pair of cer wires $0.5\;cm$ for this purpose . Calculate the fraction of ohmic losses to power transmitted if power is transmitted comment on the feasibility of doing this ?

asked Sep 27, 2016 by meena.p

1 answer

An electrical drive draws 2 kw power from AC mains [ Voltage $223 V(rms) = \sqrt {50,000}\;v$ ]. The current differs (lags) in phase by $\phi (\tan \phi = -\large\frac{-3}{4} )$ as compared to voltage . Find $I_{max}$ another device has twice the value of $R,X_c$ and $X_L$. How are the answers affected ?

asked Sep 27, 2016 by meena.p

1 answer

An electrical drive draws 2 kw power from AC mains [ Voltage $223 V(rms) = \sqrt {50,000}\;v$ ]. The current differs (lags) in phase by $\phi (\tan \phi = -\large\frac{-3}{4} )$ as compared to voltage . Find $ X_C - X_L$

asked Sep 26, 2016 by meena.p

1 answer

An electrical drive draws 2 kw power from AC mains [ Voltage $223 V(rms) = \sqrt {50,000}\;v$ ]. The current differs (lags) in phase by $\phi (\tan \phi = -\large\frac{-3}{4} )$ as compared to voltage . Find R

asked Sep 26, 2016 by meena.p

1 answer

Explain why the reactant offered by an inductor increased with increased frequency of an alternating voltage.

asked Sep 26, 2016 by meena.p

1 answer

Explain why the reactant provided by a capital to an alternating current decreases with increasing frequency .

asked Sep 26, 2016 by meena.p

1 answer

A Coil of $0.01$ Henry inductance and 1 ohm resistance is connected to $200 \;volt,50 Hz,ac $ supply . Find the impedance of the circuit and time lag between max. alternating voltage and current .

asked Sep 26, 2016 by meena.p

1 answer

Both alternating current and direct current are measured in ampere. But how is the ampere defined defined for an alternating current .

asked Sep 26, 2016 by meena.p

1 answer

A small town with a demand of $800\;kw$ of electric power at $220\;v$ is situated $15\;km$ away from an electric plant generating power at $440\;v$. The resistance of the two line wires carrying power is $0.5\;\Omega$ per km. The town gets power from the lines through a $40,000-220\;v$ Step down transformation. Neglect leaked losses . hence explain why high voltage transmission is preferred .

asked Sep 21, 2016 by meena.p

1 answer

A small town with a demand of $800\;kw$ of electric power at $220\;v$ is situated $15\;km$ away from an electric plant generating power at $440\;v$. The resistance of the two line wires carrying power is $0.5\;\Omega$ per km. The town gets power from the lines through a $4000-220\;v$ Step down transformation at a substation in the town .Characterize the step up transformer at the plant

asked Sep 21, 2016 by meena.p

1 answer

A small town with a demand of $800\;kw$ of electric power at $220\;v$ is situated $15\;km$ away from an electric plant generating power at $440\;v$. The resistance of the two line wires carrying power is $0.5\;\Omega$ per km. The town gets power from the lines through a $4000-220\;v$ Step down transformation at a substation in the town . How much power must the plant supply , assuming there is negligible power loss due to leakage ?

asked Sep 21, 2016 by meena.p

1 answer

A small town with a demand of $800\;kw$ of electric power at $220\;v$ is situated $15\;km$ away from an electric plant generating power at $440\;v$. The resistance of the two line wires carrying power is $0.5\;\Omega$ per km. The town gets power from the lines through a $4000-220\;v$ Step down transformation at a substation in the town . Estimate the power loss in the form of heat

asked Sep 21, 2016 by meena.p

1 answer

At a hydroelectric power plant , the water pressure head is at a height of 300 m and the water flow available is $100 m^3 s^{-1} $. If the turbine generator efficiency is $60\%$ estimate the electric power available from the plant $(g= 9.8 ms^{-2})$

asked Sep 20, 2016 by meena.p

1 answer

An applied voltage signal consists of a super position of a d.c voltage and a.c voltage of high frequency . The circuit consists of an inductor and a capacitor in series. will the d.c signal will appear across c and the a.c signal will appear across L ? At high frequencies

asked Sep 20, 2016 by meena.p

1 answer

Obtain the resonant frequency and Q- factor of a series circuit with $L= 3.0 \;H,C= 27\mu F$ and $R= 7.4 \Omega$ . It is desired to improve the sharpness of resonance of the circuit by reducing its full width at half max. by a factor of 2. suggest a suitable way

asked Sep 20, 2016 by meena.p

1 answer

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