Chemistry Test - 4

3-Hydroxybutanoic Acid + 3-Hydroxypentanoic Acid and Glycine + Amino Caproic Acid forms the Biodegradable polymers.

Biodegradable polymers are defined as materials whose chemical and physical characteristics undergo deterioration and completely degrade when exposed to microorganisms, aerobic, and anaerobic processes.

Assertion ⇒ Chain isomerism can be defined as having same molecular formula but the different chain.

Thus, alkanes having more than 3 carbon atoms exhibit chain isomerism.

Reason ⇒ Since every carbon in alkane has 4 σ bonds, therefore, all carbon atoms are sp³ hybridised.

Thus, both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.

Osmotic pressure, \(\pi=i \times M R T\)

Where, \(i=\) van't Hoff factor, \(M=\) Molarity \(R=\) Gas constant, \(T=\) Temperature

For \(0.500 \mathrm{MC}_{2} \mathrm{H}_{5} \mathrm{OH}(a q), i=1\), thus,

\(\pi_{C H_{6}} \mathrm{OH}(a q)=0.5 \mathrm{RT}\)

For \(0.100 \mathrm{MMg}_{3}\left(\mathrm{PO}_{4}\right)_{2}(a q), i=5\)

\(\left[\because \mathrm{Mg}_{3}\left(\mathrm{PO}_{4}\right)_{2} \rightleftharpoons 3 \mathrm{Mg}^{2+}+2 \mathrm{PO}_{4}^{3-}\right]\)

Thus, \(\pi_{\mathrm{Mg}_{3}}\left(\mathrm{PO}_{4}\right)_{2}(\mathrm{aq})=5 \times 0.1 \times \mathrm{RT}\)

\(=0.5 R T\)

For \(0.250 \mathrm{MKBr}(aq)\)

\(i=2\left[\because \mathrm{KBr} \rightleftharpoons \mathrm{K}^{+}+\mathrm{Br}^{-}\right]\)

Thus, \(\pi_{\mathrm{KB}}(a q)=2 \times 0.250 \times R T=0.5 R T\)

For \(0.125 \mathrm{MNa}_{3} \mathrm{PO}_{4}(\mathrm{aq}), i=4\)

\(\left[\because \mathrm{Na}_{3} \mathrm{PO}_{4} \rightleftharpoons 3 \mathrm{Na}^{+}+\mathrm{PO}_{4}^{3-}\right]\)

Thus, \(\pi_{\mathrm{Na_{3}} \mathrm{PO}_{4}(a q)}=4 \times 0.125 \times R T=0.5 R T\)

Therefore, all solutions have same osmotic pressure.

At equilibrium, the relation between the free energy of the reaction and equilibrium constant is as follows,

\(\Delta {G}^{\circ}=-{R T} \ln {K}_{{p}}\)

If \({K}_{{p}}=1\) at equilibrium

\(\Delta {G}^{\prime}=-{R T} \ln 1\)

or \(\Delta G^{\circ}=0\)

Enzymes requires metal ion as a cofactor  which activates their catalytic activity. For example carbonic anhydrase and alcohol dehydrogenase require zinc, arginase and ribonucleotide reductase require manganese, dinitrogenase and nitrate reductase require molybdenum, pyruvate kinase requires potassium. The metal ions Molybdenum(Mo), Zinc(Zn) and Manganese(Mn) are present at the active site of enzymes and the respective enzymes are called metalloproteins but potassium requiring enzymes are not metalloproteins as it is not a part of enzyme but it activates the enzyme.

The amount of heat required to raise the temperature of a unit mass of a substance by one-degree celsius is known as specific heat. Heat capacity is the amount of heat added to a substance to raise its temperature by one kelvin.

Thus, specific heat may be defined as heat capacity per gram.

The exponential factor represents the fraction of "reactants" that have approached the activation energy hill and made it over per number of attempts.

The exponential factor reflects the percentage of reactants who have approached and crossed the activation energy hill in the number of tries.

Zone refining is a method of purification used for semiconductors like Si, Ge and Ga.

Zone refining process is used to get the purest form of elements. It is a technique for the purification of a crystalline material and especially a metal in which a molten region travels through the material to be refined, picks up impurities at its advancing edge, and then allows the purified part to recrystallize at its opposite edge.

Two bodies at different temperatures are mixed in a calorimeter. The total internal energy of the two bodies remains conserved.

There is no heat lost since the calorimeter is insulated. If we consider both the liquids together as one system, then the work done by the system is zero.

From first law of thermodynamics,

\(\Delta \mathrm{U}=\mathrm{Q}-\mathrm{W}\)

\(\Delta \mathrm{U}=0\)

Since there is no change in internal energy, the internal energy of the system remains constant.

In group number eighteenth all the elements do not have same number of velance electrons.

In group number 18, helium contains two electrons in the valence shell, and the other elements, neon to radon, contain eight electrons in the valence shell.