Chemistry Test - 7

The oxidative rusting of iron under Earth's atmosphere is slow reaction.

The reaction rate (rate of reaction) or speed of reaction for a reactant or product in a particular reaction is intuitively defined as how fast or slow a reaction takes place. For example, the oxidative rusting of iron under Earth's atmosphere is a slow reaction that can take many years.

As we move from top to bottom the acidic nature of hydrides of the group increases as the electronegativity of atom decreases.

So, the order of acidity of hydrides of the Vth group is:

\(\mathrm{H}_{2} \mathrm{O}<\mathrm{H}_{2} \mathrm{~S}<\mathrm{H}_{2} \mathrm{Se}<\mathrm{H}_{2} \mathrm{Te}\)

Strongest acid among the given is \(\mathrm{H}_{2} \mathrm{Te}\).

Dien (Diethylenetriamine) has following structure:

In Dien, the number of donor atoms is three so it is a tridentate ligand. Each nitrogen atom is a donor atom.

\(EDT A ^{4-}\) is a hexadentate ligand. \(( COO )_{2}^{2-}\) is a bidentate ligand. \(NO _{2}^{-}\)is a monodentate ligand.

In benzyl amine \(\left( P h C H _{2} N H _{2}\right),\) the lone pair of nitrogen is not in conjugation with the benzene ring and it is free for donation to an electrophile. So, D is the most basic compound.In \(p\)-nitroaniline, acetanilide and aniline, the lone pair of nitrogen is in conjugation with the aromatic system (benzene ring). So, it is delocalized and is not freely available for donation. So, \(A, B\) and \(C\) are less basic.

In \(A g_{2} S O_{4}\), silver is present as \(A g^{+}\), in \(C u F_{2}\), copper is present as \(C u^{2+}\), in \(Z n F_{2}\), zinc is present as \(Z n^{2+}\), in \(C u_{2} C l_{2}\), the copper is present as \(C u^{+1}\).

As they are metal cations, the electrons are removed from their actual configuration to form ions.

The respective transition elements exists in:

\(A g^{+}-[A r]4 d^{10} 5 s^{0},\) (have completely filled \(d\) orbital).

\(C u^{+2}-[A r]3 d^{9} 4 s^{0},\) (have incompletely filled \(d\) orbital).

\({Zn}^{+2}-[A r]3 d^{10} 4 s^{0},\) (have completely filled \(d\) orbital).

\({Cu}^{+1}-[A r]3 d^{10} 4 s^{9},\) (have completely filled \({d}\) orbital).

Since, \(C u^{+2}\) has unpaired electron, it will show electron transitions. Therefore, will be coloured.

Tollen's Test is used to distinguish between and aldehyde and ketone. It uses the fact that aldehydes are easily oxidised to their corresponding acids while ketones are not. Tollen's reagent are aqueous ammonical silver nitrate solution which react with aldehydes as shown. \(RCHO +2 Ag ^{+}+2 OH ^{-} \rightarrow RCOO ^{-}+ Ag + H _{2} O\) . \(RCOR +2 Ag ^{+}+2 (OH) \rightarrow\) No reaction If this test is carried in glass tube, the Ag formed forms a mirror on the sides of test tube so the test is also known as silver mirror test. Aldehydes show tollen's test while acetone which is a ketone does not give tollen's test.

Given: Weight of Urea \(=12 {~g}\)

And, weight of sucrose \(=68.4 {~g}\)

We know that: Number of moles \(=\frac{\text{Weight}}{\text{Molar mass}}\)

Therefore, Moles of urea \(=\frac{12}{60}=0.2\)

(Molar mass of Urea is \(60 {gm}\). )

Moles of sucrose \(=\frac{68.4}{342}=0.2\)

(Molar mass of sucrose is \(342 {gm}\))

Since, there are equal moles of solute in equal volumes of water, the mole fraction is the same. As per Raoult's law, the relative lowering of pressure will also be the same.

Due to the generation of aluminate salts, aluminium hydroxide solubilizes in the solution. - Therefore, aluminium vessels should not be washed with materials containing washing soda because washing soda reacts with aluminium to form sodium aluminate.

All amino acids have an amine and a carboxyl group They also have a functional group which is unique to each of them.

Depending on the polarity of the functional group the amino acid can be rendered optically inactive or active. The simplest of all amino acids, Glycine which has \(H\) as a functional group lacks optical acitivity, as the saturated alpha carbon is unsubstituted. Others among the 20 amino acids have D or L stereoisomers. So, the correct answer is 'Glycine'.

Phenol is also known as Carbolic acid. In 1865, the British surgeon Joseph Lister used phenol as an antiseptic to sterilize his operating field.

Phenol is an aromatic organic compound characterized by a hydroxyl (―OH) group attached to a carbon atom that is part of an aromatic ring.

Besides serving as the generic name for the entire family, the term phenol is also the specific name of its simplest member, monohydroxybenzene (C₆H₅OH).