Chemistry: Topic-wise Test- 6 - NEET MCQ

Cl show different oxidation state as -1 to +7 due to vacant d orbital.

As oxygen is more electronegative than Cl.

Oxygen size is small hence its more electronegative and show -2 oxidation states.

2x + 7 (-2) = 0

x = +7

• Autoxidation is any oxidation that occurs in presence of oxygen.
• The term is usually used to describe the degradation of organic compounds in air (as a source of oxygen).
• Autoxidation produces hydroperoxides and cyclic organic peroxides.

Determining Anodes when connected to the Standard Hydrogen Electrode

The Standard Hydrogen Electrode (SHE) is commonly used as a reference electrode in electrochemistry and has an electrode potential of 0V. The electrode with a lower reduction potential than the SHE will act as the anode (site of oxidation), while the electrode with a higher reduction potential than the SHE will act as the cathode (site of reduction).
A: Fe/Fe²⁺ E₀= − 0.44
The reduction potential of this electrode is lower than that of the SHE, so it will act as the anode when connected to the SHE.
B: Al/Al³⁺ E₀= - 1.66
The reduction potential of this electrode is lower than that of the SHE, so it will also act as the anode when connected to the SHE.
C: F₂(g)/2F⁻(aq) E₀= + 2.87
The reduction potential of this electrode is higher than that of the SHE, so it will act as the cathode, not the anode, when connected to the SHE.
D: Cu/Cu²⁺ E₀= + 0.34
The reduction potential of this electrode is higher than that of the SHE, so it will also act as the cathode, not the anode, when connected to the SHE.

Therefore, electrodes A: Fe/Fe²⁺ (E₀= − 0.44) and B: Al/Al³⁺ (E₀= - 1.66) will act as anodes when connected to the Standard Hydrogen Electrode.

Concept of Reducing Agent:
A reducing agent is a substance that loses or "donates" an electron to another substance in a redox chemical reaction. Therefore, a good reducing agent is the one that gets oxidized easily, or in other words, the one that can easily lose electrons.

Characteristics of a Good Reducing Agent:

• Electron Loss: A better reducing agent is the one that loses more electrons. This is because by losing electrons, the reducing agent gets oxidized and in turn reduces the other substance. This is the basic principle of a redox reaction.
• Reactivity: The reactivity of the metal also determines its capacity as a reducing agent. Metals that are high in the reactivity series are good reducing agents. This is because they can easily lose electrons and get oxidized.
• Stability: Metals that are less stable are better reducing agents because they can easily lose electrons to attain a stable state.

Hence, Option A is the correct answer - a better reducing agent is the one that loses more electrons.

oxidation state of Ag in tollen’s reagent is +1.

Multidentate ligand always act as chelating Ligand

In A Ni has +4 oxidation state.

KCl.MgCl₂.6H₂O is double salt

In A one and more different types of ligands are present.

Oxalate is a bidentate ligand.

C₅H₅⁻a negative ligand.

Cis Platin (cis – [Pt(NH₃)₂(Cl)₂] is a anti cancer drug.

The correct answer is option D(None of the above)
The given compound is 4-Bromo-3methylheptanal

Alcohols have higher boiling points than aldehydes.

This is 1-phenyl propan-1-one.

The correct answer is option C
CH_3​CH₂​CONH₂​ (A)⟶ CH₃​ − CH₂ ​− NH₂​ (B)⟶ ​CH_3​ − CH₂ ​− OH
In the above sequence A & B respectively are Br₂​/KOH and HNO₂​
The first step is Hoffmann bromamide degradation reaction in which an amide (propanamide) is converted to an amine  (ethylamine) containing one carbon atom less. The reagent A is bromine in presence of KOH. In the second step, aliphatic primary amine (ethyl amine) reacts with nitrous acid (reagent B) to form aliphatic primary alcohol (ethyl alcohol).
 

Fe + HCl is preferred due to the following reasons:
- Scrap iron i.e Fe is cheap and commercially easily available
- FeCl₂ formed will get hydrolysed and release HCl, so, HCl which is required in the reaction will be produced by itself
- Hence only small amount of HCl is required to initiate the reaction.

Aniline is prepared commercially by the catalytic hydrogenation of nitrobenzene or by the action of ammonia on chlorobenzene. The reduction of nitrobenzene can also be carried out with iron borings in aqueous acid. A primary aromatic amine, aniline is a weak base and forms salts with mineral acids.

−NO₂ group is reduced to –NH₂ using H₂/Pd.

Its molecular formula is C₄H₈O₂

Diphenhydramine​ is an antihistamine mainly used to treat allergies. It can also be used for insomnia, symptoms of the common cold, tremor in parkinsonism, and nausea. It is used by mouth, injection into a vein, injection into a muscle, or applied to the skin.

RNO₂ +Fe/HCl ->RNH₂

Ephedrine is used to increase blood pressure

The correct answer is Option C.

The correct answer is Option D.
Only primary amines liberate nitrogen gas on reaction with HNO2.

p-amino azo benzene is obtained by treating diazonium chloride with aniline. The reactions are specifically acid catalyzed and involve pre‐equilibrium formation of amine and diazonium salt followed by rate‐limiting attack of the diazonium ion at a C‐atom (C‐coupling) to give the corresponding amino azo compounds.

The solutions in which the electrodes are immersed are called electrolytes. The chemical reaction that takes placein a galvanic cell is the redox reaction. One electrode acts as anode in whichoxidation takes place and the other acts as the cathode in which reductiontakes place.the half-cell occurs is called reduction half-cell and the reaction taking place in it is called reduction half-cell reaction. The electrode where oxidation occurs is called anode and the electrode where reduction occurs is termed cathode. Electrons flow from anode to cathode in the external circuit.

The standard potential of hydrogen electrode is assumed to be zero at all temperature.

The Standard hydrogen electrode (abbreviated SHE), is a redox electrode which forms the basis of the thermodynamic scale of oxidation-reduction potentials. Its absolute electrode potential is estimated to be 4.44 ± 0.02 V at 25 °C, but to form a basis for comparison with all other electrode reactions, hydrogen's standard electrode potential (E⁰) is declared to be zero volts at all temperatures.