Chemistry Test - 11

Potassium superoxide \(\left(\mathrm {K O_{2}}\right)\) is used in oxygen cylinders in space and submarines because it acts as an oxygen

generator. It absorbs the \(\mathrm {C O_{2}}\) and increases the \(\mathrm {O_{2}}\) content.

This can be shown by the equation:

\(4 \mathrm{KO}_{2}+2 \mathrm{CO}_{2} \rightarrow 2 \mathrm{~K}_{2} \mathrm{CO}_{3}+3 \mathrm{O}_{2}\)

As we can see in the equation, \(\mathrm {C O_{2}}\) is getting absorbed by \(\mathrm {K O_{2}}\) and oxygen is produced.

In places like space or inside submarines underwater, the level of oxygen is very low and oxygen cylinders are used.

Increasing the efficiency of these oxygen cylinders will help the cylinder to last longer.

\(n\) -factor \(=\frac{n_{1} \times n_{2}}{n_{1}+n_{2}}=\frac{4 \times 2}{4+2}=\frac{4}{3}\)

Equivalent weight \(=\frac{\text { mol wt. }}{n \text { - factor }}\)

\(=\frac{M \times 3}{4}\)

\(=\frac {3M}{4}\)

The enormous diversity of protein molecules is due mainly to the diversity of amino acid sequences within the protein molecule. Proteins are building blocks of the body. The proteins are made up of amino acids. The amino acids are linked together by peptide bonds to form a protein. The amino acids consist of amine group made up of nitrogen and hydrogen and the carboxyl group at the end and a side chain of R group which is specific to a particular amino acid. This specific group brings a variability to the proteins. If R group is H it is glycine while if it is CH₂, it is alanine. The sequence of amino acids determines the protein.

\(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{MgBr}\) reacts with water to give ethane.

Since, grignard reagent, \(\mathrm{RMgX}\) is highly reactive with water.

\(\mathrm{CH}_{4}+\mathrm{H}_{2} \mathrm{O} \longrightarrow\) No reaction

\(\mathrm{C}_{2}^{-} \mathrm{H}_{5} \mathrm{Mg}^{+} \mathrm{Br}+\mathrm{H}-\mathrm{OH} \quad \longrightarrow \mathrm{C}_{2} \mathrm{H}_{6}+\mathrm{Mg}(\mathrm{OH}) \mathrm{Br}\)

\(\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{OH}+\mathrm{H}_{2} \mathrm{O} \longrightarrow\) No reaction

\(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OC}_{2} \mathrm{H}_{5}+\mathrm{H}_{2} \mathrm{O} \longrightarrow\) No reaction

For acids, Normality = molarity × basicity

So, Normality = 0.3 × 2 = 0.6

∵ The basicity of H₃PO₃ is 2 because one of the H is not replaceable in H₃PO₃. The H atoms which are linked to oxygen are replaceable, but H atom linked directly to central atom P is nonreplaceable.

The solvent affects the rate of reaction because solvents may or may not surround a nucleophile, thus hindering or not hindering its approach to the carbon atom. Polar aprotic solvents, like tetrahydrofuran, are better solvents for this reaction than polar protic solvents because polar protic solvents will hydrogen bond to the nucleophile, hindering it from attacking the carbon with the leaving group. A polar aprotic solvent with a low dielectric constant or a hindered dipole end will favor SN² manner of nucleophilic substitution reaction. Examples: DMSO, DMF, acetone etc. In polar aprotic solvent, nucleophilicity parallels basicity.

Ionization enthalpies of transition metals are intermediate between those of s- block and p- block elements as they are placed between s- block and p- block in the periodic table.

• The s-block elements are present on one side and the p-block elements are present on the opposite side of the periodic table and involve the filling of the s- orbitals and p- orbitals respectively.
• In between these representative elements i.e., the s- block and the p- block elements lie the d- block elements also known as the transition metals because their properties lie in between the s- block and p-block elements.

Transition metal compounds are usually coloured. This is due to the electronic transition within the d-orbitals.

Transition elements (also known as transition metals) are elements that have partially filed d orbitals.

Many ionic and covalent compounds of transition elements are coloured and this colouring property is due to \(d-d\) electronic excitation. The colour of the compound is complementary to the colour absorbed.

Antibodies are immune system-related proteins called immunoglobulins. Each antibody consists of four polypeptides– two heavy chains and two light chains joined to form a "Y" shaped molecule. The amino acid sequence in the tips of the "Y" varies greatly among different antibodies.

Dichloro diphenyl trichloroethane is a chemical compound commonly used as Insecticide.

Dichlorodiphenyltrichloroethane is commonly known as DDT.It is also called 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane.

It was first developed by Othmar Zeidler in 1874.The insecticidal action of DDT was discovered by the Swiss chemist Paul Hermann Müller in 1939.Paul Hermann Müller was awarded the Nobel Prize in Physiology in 1948 "for his discovery of the high efficiency of DDT as a contact poison against several arthropods".Dichloro diphenyl trichloroethane became infamous for its environmental impacts.