Recent questions tagged physical-chemistry

The average speed of an ideal gas molecule at $27^{\large\circ}C$ is 0.3 m/s. Calculate the average speed at $927^{\large\circ}C$

asked Feb 21, 2014 by sharmaaparna1

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A vertical hollow cylinder of height 1.52m is fitted with a movable piston of negligible mass and thickness. The lower half of the cylinder contains an ideal gas and the upper half is filled with mercury. The cylinder is initially at 300K. When the temperature is raised half of the mercury comes out of the cylinder . Find the temperature assuming the thermal expansion of mercury to be negligible.

asked Feb 21, 2014 by sharmaaparna1

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A vessel of volume 5 litre contains 1.4g of nitrogen at temperature 1800K. Find the pressure of the gas if $30\%$ of its molecules are dissociated into atoms at this temperature.

asked Feb 20, 2014 by sharmaaparna1

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An evacuated glass vessel weighs 50.0g when empty 148.0 g when filled with a liquid of density $0.98gmL^{-1}$ and 50.5g when filled with an ideal gas at 760mm Hg of 300K.Determine the molecular weight of the gas.

asked Feb 20, 2014 by sharmaaparna1

1 answer

The Volume of the average adult lung when expanded is about $6L$ at $98.4^{\large\circ}F$. If the pressure of oxygen in inhaled air is $168mm$ of $Hg$ , calculate the mass of $O_2$ required to occupy the lung at $98.4^{\large\circ}F$.

asked Feb 20, 2014 by sharmaaparna1

1 answer

Two glass bulbs with equal volume are connected by a narrow tube and filled with a gas at $0^{\large\circ}C$ and pressure of $76\;cm\; Hg$ . One of the bulb is then placed in a water bath maintained at $62^{\large\circ}C$. What is the new value of the pressure inside the bulbs? The volume of the connecting tube is negligible.

asked Feb 20, 2014 by sharmaaparna1

1 answer

1.47 litre of a gas is collected over water at $30^{\large\circ}C$ and 744mm of Hg . If the gas weight 1.98g and vapour pressure of water at $30^{\large\circ}C$ is 32mm , What is the molecular weight of gas?

asked Feb 20, 2014 by sharmaaparna1

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A monoatomic ideal gas undergoes a process in which the ratio of P to V at any instant is constant and equal to unity. The molar heat capacity of gas is:

asked Feb 20, 2014 by sharmaaparna1

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In Victor Mayers experiment 0.23g of a volatile solute displaced air which measures 112mL at NTP .Calculate the vapour density and molecular weight of substance

asked Feb 20, 2014 by sharmaaparna1

1 answer

3.7 g of a gas at $25^{\large\circ}C$ occupy the same volume as 0.184g of $H_2$ at $17^{\large\circ}C$ at same pressure. What is moleculer weight of gas?

asked Feb 20, 2014 by sharmaaparna1

1 answer

The Edison storage cell is represented as $Fe(s)/FeO(s)/KOH(aq)/Ni_2O_3(s)/Ni(s)$.The half cell reactions are $Ni_2O_3(s)+H_2O(l)+2e^-\rightarrow 2NiO(s)+2OH^-(aq)\Rightarrow E^0=0.4V$,$FeO(s)+H_2O(l)+2e^-\rightarrow Fe(s)+2OH^-(aq)\Rightarrow E^0=-0.87.V$.What will be the maximum amount of electrical energy that can be obtained from one mole of $Ni_2O_3$

asked Feb 18, 2014 by sreemathi.v

1 answer

The Edison storage cell is represented as $Fe(s)/FeO(s)/KOH(aq)/Ni_2O_3(s)/Ni(s)$.

asked Feb 18, 2014 by sreemathi.v

1 answer

$H_2O_2$ can be prepared by successive reactions

asked Feb 18, 2014 by sreemathi.v

1 answer

The voltage of cell given is -0.46V $Pt/H_2$(atm)/$NaHSO_3(0.4M),Na_2SO_3(6.44\times 10^{-3}M)\parallel Zn^{+2}(0.3M)/Zn(g)$.Also $Zn^{+2}+2e^-\rightarrow Zn(s) \leftrightharpoons E^0=-0.763$V.Then the value of $K_2=\large\frac{[H^+][SO_3^{-2}]}{[HSO_3^-]}$

asked Feb 18, 2014 by sreemathi.v

1 answer

1.26gm weight of NaOH required to be added in R.H.S to consume all the $H^+$ present in R.H.S of cell of emf to .701V at $25^{\large\circ}C$.Given: $Zn/Zn^{+2}(0.1M)\parallel HCl$(1litre)$/H_2/$(1atm)/P:-$E^0_{Zn/Zn^{+2}}=0.7602$.The emf of cell after addition of NaOH will be

asked Feb 18, 2014 by sreemathi.v

1 answer

Calculate the minimum weight of NaOH required to be added in R.H.S to consume all the $H^+$ present in R.H.S of cell of emf to .701V at $25^{\large\circ}C$.Given: $Zn/Zn^{+2}(0.1M)\parallel HCl$(1litre)$/H_2/$(1atm)/P:-$E^0_{Zn/Zn^{+2}}=0.7602$

asked Feb 18, 2014 by sreemathi.v

1 answer

Given the overall formation constant of the $[Fe(CN)_6]^{-4}$ ion as $10^{35}$ and the standard potential for half reaction $Fe^{+3}+e^-\leftrightharpoons Fe^{+2},E^0=0.77V$,$[Fe(CN)_6]^{-3}+e^-\leftrightharpoons [Fe(CN)_6]^{-4},E^0=0.36V$.Then the overall formation constant of $[Fe(CN)_6]^{-3}$ ion is

asked Feb 18, 2014 by sreemathi.v

1 answer

The EMF of cell Hg/mercurous nitrate (0.01M)$\parallel$ mercurous nitrate (0.1M)/Hg was found to be 0.0295V at $25^{\large\circ}C$ .Then molecular formula of mercurous nitrate is

asked Feb 18, 2014 by sreemathi.v

1 answer

From following molar conductivities at infinite dilution $\Lambda_m^{\large\circ}$ for $Ba(OH)_2=457.6\Omega^{-1}cm^2mol^{-1}$,$\Lambda_m^{\large\circ}$ for $BaCl_2=240.6\Omega^{-1}cm^2mol^{-1}$,$\Lambda_m^{\large\circ}$ for $NH_4Cl=129.8\Omega^{-1}cm^2mol^{-1}$.The $\Lambda_m^{\large\circ}$ for $NH_4OH$ is

asked Feb 18, 2014 by sreemathi.v

1 answer

Calculate EMF of concentration cell consisting of zinc electrodes,one immersed in a solution of 0.01M $Zn^{+2}$ ions and the other in a solution of 0.1M $Zn^{+2}$ ions at $25^{\large\circ}C$.The two solution are separated by a salt bridge

asked Feb 18, 2014 by sreemathi.v

1 answer

The EMF of electrode -concentration cell $Zn-Hg(C_1)/Zn^{+2}(aq)/Zn-Hg(C_2)$ at $25^{\large\circ}C$ if the concentration of zinc amalgam are $C_1=2g$ per 100g of mercury and $C_2=1g$ per 100g of mercury.

asked Feb 18, 2014 by sreemathi.v

1 answer

For the following galvanic cell the emf will be at $25^{\large\circ}C$.$Ag/AgCl(s),KCl(0.2M\parallel KBr(0.001M).AgBr(s)/Ag$.The solubility product of $AgCl$ & $AgBr$ are $2.8\times 10^{-10}$ and $3.3\times 10^{-13}$ respectively.

asked Feb 18, 2014 by sreemathi.v

1 answer

The standard reduction potential of $Ag^+/Ag$ electrode at 298K is 0.79V.$K_{sp}$ of Ag$^+$ is $8.7\times 10^{-17}$.Evaluate the standard reduction potential of $I^-/AgI/Ag$ electrode

asked Feb 18, 2014 by sreemathi.v

1 answer

The half potential of $Cl^{-1}(C_1)/AgCl/Ag$ electrode.Given the value of $E^0$ for $Ag^++e^-\rightarrow Ag$ and $K_{sp}$ of AgCl is

asked Feb 18, 2014 by sreemathi.v

1 answer

The emf of cell $Zn/ZnCl_2(0.05mol\;dm^{-3})/Ag^+/AgCl(s)/Ag$ is 1.015V at 298K,the silver electrode being positive,while the temperature coefficient of its emf is $-0.00492VK^{-1}$.Write down the equation for reaction occuring when the cell is allowed to discharge and calculate changes in entropy (s) accompanying this reaction,at 298K?

asked Feb 18, 2014 by sreemathi.v

1 answer

The emf of cell $Zn/ZnCl_2(0.05mol\;dm^{-3})/Ag^+/AgCl(s)/Ag$ is 1.015V at 298K,the silver electrode being positive,while the temperature coefficient of its emf is $-0.00492VK^{-1}$.Write down the equation for reaction occuring when the cell is allowed to discharge and calculate changes in free energy(G)?

asked Feb 18, 2014 by sreemathi.v

1 answer

Consider the relation,$2Ag^++Cd\rightarrow 2Ag+Cd^{+2}$ the standard electrode potentials for $Ag^+/Ag$ and $Cd^{+2}/Cd$ couples $0.8\;V$ and $0.04\;V$ respectively Then the emf of given reaction will be (if $[Cd^{+2}]=0.1M,[Ad^+]=1M)$

asked Feb 18, 2014 by sreemathi.v

1 answer