UP PGT Chemistry Mock Test - 6 - UPTET MCQ

Both elements are present in the same substance . Such reaction is called intramolecular redox reaction.

The correct answer is Option C. 

Noble gases have completely filled the outer shell/valence shell. Due to this reason they are very stable and do not react with other elements. Hence noble gases are called inert gases means they do not react with other elements to form chemical compounds.
 

The elements of "s" and "p" blocks except "d" group elements are called as representative elements. Their outer shells are not completely filled with electrons. The elements get the nearest inert gas configuration by losing or gaining or sharing of electrons. 

C₆H₆(l) + 15/2O₂(g) → 6CO₂(g) + 3H₂O(l)
∆H_r = (∆H_c)_C6H6 ⇒-3261  = ∑H_product - ∑H_reactant = 6(-393.5) -3(-283.83) - ∆_fH_C6H6
∆H_f = 48 kJ mol^-1

Maximum ores are of group 16 elemnts (O, S etc).

For H - atom , Z = 1

Reason behind it is that fluorine is more electronegative element than oxygen.

= 946 + 249 - 607 - 418 = 1195 - 1025 = 170 kJ mo^l-1 
Resonance energy = Observed heat of formation – calculated heat of formation 
= 82 -170 = 88 kJ mol^-1

The correct answer is option A
2.03x 10^-4
The given equation is :-
 N2​(g)+3H2​(g) ⇌ 2NH_3​(g)
Initial moles : 1             3         0
At eqm ;       (1−x)    (3−3x)   (2x)               
(let)
Total moles of equation
 =1 − x + 3 − 3x + 2x = (4−2x)
Now, X(NH_3​) = 
⇒ 2x = 2 − x
⇒ 3x = 2 ⇒ x = 0.66 = 
32​
Now, at equation, moles of N₂​= 1/3, moles of NH_3​ = 4/3
             moles of H2 ​ =3 − 2 = 1

 

Rate of reaction can be measured in terms of Rate of disappearance of reactant or rate of apperance of product.

The presence of particulate matter in polluted air catalyses the oxidation of sulphur dioxide to sulphur trioxide. Oxides of Nitrogen: Di-nitrogen and di-oxygen are the main constituents of air. These gases do not react with each other at a normal temperature.

Pencillin causes allergic reactions.

Even though each atom has more electrons as you move from left to right across the periodic table, the atomic radius decreases. The reason is that you're also adding more protons, which exert a stronger attractive force on the electrons, drawing them in a tiny bit closer. Ionic radius also decreases, although not for the exact same reason.

A carbon atom has four valence electrons. The number of valence electrons of any atom of an element can be determined by the period table group in which the element is classified. There are a total of 18 groups on the period table group.

 XeF₂-sp³d hybridised Xe
Three lone pairs on equatorial positions to minimise repulsion; two F-atom at axial position. Thus, it is linear.

(a) TeF₂,Te₅₀ - Six electrons in valence shell

(b)   hybridised l- atom with three lone pairs at equatorial positions to minimise repulsion thus, linear.

(c) SoCI₃ - sp³-hybridised pyramidal Sb-one lone pair on Sb.
(d) BaCI₂ - ionic .

It shows geometrical isomerism as well as it has a chiral carbon. Hence, A will have four stereoisomers

The greenhouse effect increases the global temperature

The correct answer is Option A.

Out of the given four compounds only the first one has a chiral carbon. Hence compound A is optically active and it can rotate the plane polarised light.
 

Selectivity is the ability to direct the reaction to get a particular product. Here we change the catalyst and we obtain different products with reactant remaining the same.

• Colloidal system is a mixture of two substances, one of which, called the dispersed phase (or colloid), is uniformly distributed in a finely divided state through the second substance, called the dispersion medium (or dispersing medium).
• So, here are 2 phases.

The standard electrode potential, E₀, is a measure of the tendency of a chemical species to be reduced. The higher the E₀ value, the greater the tendency for reduction.

In a redox reaction, the chemical species that gets reduced acts as the oxidising agent. Therefore, the species with the highest E₀ value will be the strongest oxidising agent.

Given the E0 values:

• Fe³⁺ / Fe²⁺ = +0.77V
• I₂(s) / I^- = +0.54V
• Cu²⁺ / Cu = +0.34V
• Ag⁺ / Ag = +0.80V

From the given values, it is clear that Ag+ / Ag has the highest E₀ value (+0.80V). Therefore, Ag+ is the strongest oxidising agent among the given options.

Conclusion:

• Ag+ is the strongest oxidising agent because it has the highest standard electrode potential (E₀) value among the given species.
• Remember, the higher the E₀ value, the greater the tendency of the species to be reduced, and hence, stronger is its oxidising power.

As per IuPAC nomenclature of periodic elements greater than 100, Un means 1, nil means 0 and oct means 8, so the element numbered 108 is unniloctium. It’s chemical names is Hassium and is represented by the symbol “Hs”. It is highly radioactive in nature and man made.

ΔTb/Kb = ΔTf/Kf
0.186/18.6 = ΔTb/0.512
ΔTb = 0.1x0.512
= 0.0512.
Boiling point = boiling point (of water) + ΔTb
=> 100 + 0.0512
= 100.0512

The correct answer is Option B.
The 1st option has R configuration and 2nd has S configuration hence they are non super imposable mirror images of each other and are enantiomers.

Na₂[Fe(CN)₅NO] is Sodium nitroprusside.

 (b)

(a) When Si is doped with electron-deficient impurity -(p -type)

(b) When Si is doped with electron-rich impurity-(n-type)

(c) In case of semiconductors, the gap between the valence band and conduction band is small. Some electrons may Jump to conduction band and thus, conduction is observed. Semiconductors of this type are called intrinsic semiconductors.

(d) Insulators are non-conducting with high energy gap.