DSSSB PGT Chemistry Mock Test - 4 - DSSSB TGT/PGT/PRT MCQ

Hands will be at right angle twice every hour except from 2 to 4 and 8 to 10 where hands will be at right angle only thrice instead of four times.
Thus, hands will be at right angle 22 times in 12 hours or 44 times in 24 hrs.

As on melting, liquid is formed similarly on freezing solid is formed.

Acids taste sour due to their acidic properties and interaction with the taste buds on our tongues. The sour taste is a result of the release of hydrogen ions and their interaction with specific receptors on our taste buds. Carbon dioxide is incombustible and also does not support burning. Hence, it is used in fire extinguishers.

The controversy is about the monsoon fed river and the glacier fed river.

it is stated clearly in the first line of the passage that the purpose of control system is to keep the out constant inspite of changes in load.

The SP = 106.25% of the CP. Thus, CP = 29.75/1.0625
= ₹ 28.

‘रचनाकार’ अर्थात रचना को करने वाला।
जिस समास का उत्तरपद प्रधान हो और पूर्वपद गौण एवं 'को' चिह्न का लोप हो उसे कर्म तत्पुरुष समास कहते हैं। अत: यह कर्म तत्पुरूष समास का उदाहरण है।
उदाहरण:
शाकाहरी = शाक को खाने वाला।

‘अत्याधिक’ अर्थात भरपूर मात्रा।
‘स्वल्प’ अर्थात कम।
‘अग्रणी’ अर्थात जो सबसे आगे रहता हो।
‘जलचर’ अर्थात जल में विचरने वाले जीव।
‘जिजीविषु’ अर्थात अधिक समया तक जीते रहने को इच्छुक।

दो वाक्यों में एक वाकया प्रधान और दूसरा वाक्य गौण हो तथा आपस में (कि, जो, क्योंकि, जितना -उतना, जैसा -वैसा, जब -तब, जहाँ -वहाँ, जिधर -उधर )से जुड़े होते है, "तो" मिश्र वाक्य का योजक चिन्ह है। अतः दिया गया वाक्य मिश्र वाक्य है।

सुशीला स्त्रीलिंग शब्द है। स्त्रीलिंग शब्द है जैसे- प्रार्थना, वेदना, प्रस्तावना, रचना, घटना इत्यादि। (इ) उकारान्त संज्ञाएँ। जैसे- वायु, रेणु, रज्जु, जानु, मृत्यु, आयु, वस्तु, धातु इत्यादि। अपवाद- मधु, अश्रु, तालु, मेरु, हेतु, सेतु इत्यादि।

n can vary from to 10 and can be +ve or –ve.

ZnS shows Frenkel defect.

Molecular solids consist of atoms or molecules held to each other by dipole-dipole interactions, London dispersion forces, hydrogen bonds, or any combination of these. 

Additional Information: Hydrogen bonding refers to the formation of Hydrogen bonds, which are a special class of attractive intermolecular forces that arise due to the dipole-dipole interaction between a hydrogen atom that is bonded to a highly electronegative atom and another highly electronegative atom which lies in the vicinity of the hydrogen atom. 

Dalton’s atomic theory stated that atoms were indivisible. However, the discovery of subatomic particles (such as protons, electrons, and neutrons) disproved this postulate.

Given m_p = 1.67×10^-27kg
h = 6.63×10^-34Js
v = 1.0×10³ms-1

We know wavelength λ = h/mv
∴λ = 6.63×10^-34/(1.67×10^-27 × 1.0×10³)
= 0.40×10^-10
≈ 0.40nm

Hence, Option (B) is the Correct Answer.

• Number of radial nodes = n - l – 1

where n = principal quantum number, l = azimuthal quantum number

• For 3p orbital, n = 3 – 1 – 1 = 1
• Number of radial nodes = 3 – 1 – 1 = 1. 

Bredig's arc method is a method of preparation of the colidal solution of metals such as silver, gold, platinum etc. Copper sol is not prepared using Bredig's arc method.

The correct answer is Option B.
An emulsion is a colloid of two or more immiscible liquids where one liquid contains a dispersion of the other liquids. 
Examples: Oil and water mixtures are emulsions when shaken together. The oil will form drops and disperse throughout the water. So, curd is not an emulsion.
 
Foam is a substance where air or gas bubbles are trapped inside a solid or liquid. 
Examples: Styrofoam, whipped cream, soap bubbles. So, mist is not a foam.
 
An aerosol is a colloid of fine solid particles or liquid droplets in air or another gas. Aerosols can be natural or not. An Example of natural aerosol is fog. Examples of artificial aerosols are dust, particulates, air pollutants and smoke.
 
Solid sol is a type of colloid of the form of one solid dispersed in another continuous solid. So, cake is not solid sol.

Chemical Kinetics deals with rate of a Chemical reactions.

The correct answer is option A

E cell is 0 in equilibrium, that is Ecathode becomes equal to E anode ……….
EZero cell becomes zero when both the electrodes are of the same metal but of different concentration i.e for concentration cell……
We know that EZero cell is - Ezerocathode -E zeroanode (since cathode and anode are same ) so EZero =0
 

The correct answer is Option B.
 
∆T_b =(K_b × 1000 × W₂) / M₂ × W₁
⇒ M₂ = (K_b × 1000 × W₂) / ∆T_b × W₁
= (1.71 × 1000 × 2) / 1 × 100
= 34.2g

The enthalpies of fusion for all reactions are always positive because melting of a solid is an endothermic process in which heat is supplied to the reaction Hence the sum of enthalpies of the product is greater than the sum of enthalpies of the reactant.

The negative electron gain enthalpy of fluorine is less than that of chlorine. It is due to small size of fluorine atom. As a result, there are strong interelectronic repulsions in the relatively small 2p orbitals of fluorine and thus, the incoming electron does not experience much attraction.

Cl, O, and N forms Cl₂, O₂ and N₂ respectively to satisfy octet rule but He has noble gas configuration so do not form any compound and exist as monoatomic gas.

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

Requirement of macronutrient per acre of the land is 5 to 200 kg

various oxides of sulphur, nitrogen, carbon, halogens causes Tropospheric pollution

The correct answer is option A
 
Higher temperatures  speed up the effect of enzyme activity, while lower temperatures decrease the rate of an enzyme reaction. if the temperature is too high, an enzyme will denature, which causes the shape of the enzyme to change. If the enzyme's shape changes, it cannot bind to the substrate.