After removing the outer shell ( 'CaCO_3' ) of two eggs in đil 'HCl,' one is placed in distilled 'H_2 O' and the other is placed'in a saturated solution ' of NaCl. Explain the observation?

What happens when an egg is kept in saturated solution of NaCl after removing its hard shell in dil. HCl?

Fuel cells are galvanic cells in which the chemical energy of fuel is directly converted into electrical energy. Type of fuel cell is a hydrogen - oxygen fuel cell. It consists of two electrodes made up of two porous graphite impregnated with a catalyst (platinum, silver, or metal oxide). The electrodes are placed in aqueous solution of NaOH. Oxygen nad hydrogen are continuously fed into the cell. Hydrogen gets oxidized to H^(oplus) which is neutralized by overset(Θ)(OH) , ie., anodic reaction. H_(2) hArr 2H^(oplus) + 2e^(-) 2H^(oplus) + 2 overset(Θ)(OH) hArr 2H_(2)O H_(2) + 2 overset(Θ)(OH) hArr 2H_(2)O + 2e^(-) At cathode, O_(2) gets reduced to overset(Θ)(OH) i.e., O_(2) + 2H_(2)O + 4e^(-) hArr overset(Θ)(4)OH Hence, the net reaction is 2H_(2) + O_(2) hArr 2H_(2)O The overall reaction has Delta H= -285.6kJ mol^(-1) and Delta G= -237.4kJ mol^(-1) " at " 25^(@)C Suppose the concentration of hydroxide ion in the cell is doubled, then the cell voltage will be

Which of the following statements are correct? Fuel cells are galvanic cells in which the chemical energy of fuel is directly converted into electrical energy. Type of fuel cell is a hydrogen - oxygen fuel cell. It consists of two electrodes made up of two porous graphite impregnated with a catalyst (platinum, silver, or metal oxide). The electrodes are placed in aqueous solution of NaOH. Oxygen nad hydrogen are continuously fed into the cell. Hydrogen gets oxidized to H^(oplus) which is neutralized by overset(Θ)(OH) , ie., anodic reaction. H_(2) hArr 2H^(oplus) + 2e^(-) 2H^(oplus) + 2 overset(Θ)(OH) hArr 2H_(2)O H_(2) + 2 overset(Θ)(OH) hArr 2H_(2)O + 2e^(-) At cathode, O_(2) gets reduced to overset(Θ)(OH) i.e., O_(2) + 2H_(2)O + 4e^(-) hArr overset(Θ)(4)OH Hence, the net reaction is 2H_(2) + O_(2) hArr 2H_(2)O The overall reaction has Delta H= -285.6kJ mol^(-1) and Delta G= -237.4kJ mol^(-1) " at " 25^(@)C A fuel cell is I. A voltaic cell in which continuous supply of fuels are sent at anode to perform oxidation II. A voltaic cell in which fuels such as CH_(4), H_(2) and CO are used up at anode. III. One which involves the reaction of H_(2)- O_(2) fuel cell such as: Anode 2H_(2) + 4 overset(Θ)(OH) rarr 4H_(2)O(I) + 4e^(-) cathode : O+ 2H_(2)O(I) + 4e^(-) rarr 4 overset(Θ)(OH) IV. The efficiency of H_(2)-O_(2) fuel cell is 70 to 75%

Fuel cells are galvanic cells in which the chemical energy of fuel is directly converted into electrical energy. Type of fuel cell is a hydrogen - oxygen fuel cell. It consists of two electrodes made up of two porous graphite impregnated with a catalyst (platinum, silver, or metal oxide). The electrodes are placed in aqueous solution of NaOH. Oxygen and hydrogen are continuously fed into the cell. Hydrogen gets oxidized to H^(oplus) which is neutralized by overset(Θ)(OH) , ie., anodic reaction. H_(2) hArr 2H^(oplus) + 2e^(-) 2H^(oplus) + 2 overset(Θ)(OH) hArr 2H_(2)O H_(2) + 2 overset(Θ)(OH) hArr 2H_(2)O + 2e^(-) At cathode, O_(2) gets reduced to overset(Θ)(OH) i.e., O_(2) + 2H_(2)O + 4e^(-) hArr overset(Θ)(4)OH Hence, the net reaction is 2H_(2) + O_(2) hArr 2H_(2)O The overall reaction has Delta H= -285.6kJ mol^(-1) and Delta G= -237.4kJ mol^(-1) " at " 25^(@)C If the cell voltage is 1.23V for the H_(2)-O_(2) fuel cell and for the half cell: O_(2) + 2H_(2) O + 4e^(-) hArr 4 overset(Θ)(OH) " has " E^(Θ) = 0.40V , then E^(Θ) " for " 2H_(2)O + 2e^(-) hArr H_(2) + 2 overset(Θ)(OH) will be

The following four colourless salt solutions are placed in separate test tubes and a strip of a copper is placed in each. Which of the following solution will finally turn blue? (1)NaCl (2)AgNO3 (3)ZnSO4 (4)Cd(NO3)2

The chemical reaction between marble and dilute HCl is given CaCO_3+2HCl rarr CaCl_2+H_2O+CO_2 Suggest any two ways you would choose to incease the rate of this chemical reaction. Explain the reason.

A galvanic cell is constructed of two hydrogen electrodes, one immersed in a solution with H^+ at 1M and the other in 1M KOH. Calculate E_(cell) . If 1M KOH solution is replaced by 1M NH_3 , will E_(cell) be higher or lower than in 1M KOH?