UP PGT CBT Mock Test Based on PYQs

Question 1

In thermodynamics, which of the following is the correct relationship between enthalpy change ($\Delta H$) and internal energy change ($\Delta E$) at constant pressure?

Accepted Answer

$\Delta H = \Delta E + P\Delta V$

Answer

$\Delta E = \Delta H + P\Delta V$

Answer

$\Delta H = \Delta E + V\Delta P$

Answer

$H = E - PV$

Question 2

According to the Second Law of Thermodynamics and Clausius' statement, the entropy of the universe:

Accepted Answer

हमेशा बढ़ती है और अधिकतम की ओर अग्रसर होती है / Always increases and tends towards a maximum

Answer

हमेशा स्थिर रहती है / Remains constant

Answer

हमेशा घटती है और शून्य की ओर अग्रसर होती है / Always decreases and tends towards zero

Answer

चक्रीय रूप से दोलन करती है / Oscillates cyclically

Question 3

For the gaseous ammonia synthesis reaction:$$\mathbf{N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)} \quad (\Delta H < 0)$$what is the correct relationship between equilibrium constants $K_p$ and $K_c$?

Accepted Answer

$K_p = K_c(RT)^{-2}$

Answer

$K_p = K_c(RT)^{2}$

Answer

$K_p = K_c(RT)^{-1}$

Answer

$K_p = K_c(RT)$

Question 4

In electrochemistry, what is the unit of the cell constant ($G^*$) of a conductivity cell?

Accepted Answer

$	ext{cm}^{-1}$ (या $	ext{m}^{-1}$)

Answer

$\mathbf{	ext{ohm}^{-1}	ext{ cm}^{-1}}$

Answer

$\mathbf{	ext{ohm}\cdot	ext{cm}}$

Answer

$\mathbf{S\cdot	ext{cm}^2\cdot	ext{mol}^{-1}}$

Question 5

In the galvanic cell $\mathrm{Zn(s) | Zn^{2+}(aq) \,\parallel\, Cu^{2+}(aq) | Cu(s)}$, which is the negative electrode and what reaction occurs on it?

Accepted Answer

$\mathrm{Zn}$ इलेक्ट्रोड (एनोड), जहाँ ऑक्सीकरण अभिक्रिया होती है / $\mathrm{Zn}$ electrode (anode), where oxidation occurs

Answer

$\mathrm{Cu}$ इलेक्ट्रोड (कैथोड), जहाँ अपचयन अभिक्रिया होती है / $\mathrm{Cu}$ electrode (cathode), where reduction occurs

Answer

$\mathrm{Zn}$ इलेक्ट्रोड (कैथोड), जहाँ अपचयन अभिक्रिया होती है / $\mathrm{Zn}$ electrode (cathode), where reduction occurs

Answer

$\mathrm{Cu}$ इलेक्ट्रोड (एनोड), जहाँ ऑक्सीकरण अभिक्रिया होती है / $\mathrm{Cu}$ electrode (anode), where oxidation occurs

Question 6

What is the order of reaction for the photochemical reaction $\mathrm{H_2(g) + Cl_2(g) \xrightarrow{h
u} 2HCl(g)}$ carried out over water in the presence of sunlight?

Accepted Answer

शून्य कोटि (Zero order)

Answer

प्रथम कोटि (First order)

Answer

द्वितीय कोटि (Second order)

Answer

तृतीय कोटि (Third order)

Question 7

Which of the following represents the correct exponential form of the Arrhenius equation depicting the temperature dependence of reaction rate constant ($k$)?

Accepted Answer

$k = A e^{-E_a/(RT)}$

Answer

$k = A e^{E_a/(RT)}$

Answer

$k = A e^{-RT/E_a}$

Answer

$k = A e^{-E_a/T}$

Question 8

What is the effect of an increase in temperature on the surface tension of a pure liquid?

Accepted Answer

पृष्ठ तनाव घटता है / Surface tension decreases

Answer

पृष्ठ तनाव बढ़ता है / Surface tension increases

Answer

पृष्ठ तनाव अपरिवर्तित रहता है / Surface tension remains unchanged

Answer

पहले बढ़ता है फिर तेजी से घटता है / First increases then rapidly decreases

Question 9

According to colloidal chemistry, milk is which of the following types of colloidal systems?

Accepted Answer

पायस (Emulsion) - जल में वसा का परिक्षेपण / Emulsion - dispersion of fat in water

Answer

जेल (Gel) - ठोस में द्रव का परिक्षेपण / Gel - dispersion of liquid in solid

Answer

सॉल (Sol) - द्रव में ठोस का परिक्षेपण / Sol - dispersion of solid in liquid

Answer

झाग (Foam) - द्रव में गैस का परिक्षेपण / Foam - dispersion of gas in liquid

Question 10

According to Thomas Andrews' isothermal experiments, what is the exact value of the critical temperature ($T_c$) for carbon dioxide ($\mathrm{CO_2}$) gas?

Accepted Answer

$31.1^\circ	ext{C}$ ($304.25	ext{ K}$)

Answer

$0.0^\circ	ext{C}$ ($273.15	ext{ K}$)

Answer

$100.0^\circ	ext{C}$ ($373.15	ext{ K}$)

Answer

$-78.5^\circ	ext{C}$ ($194.65	ext{ K}$)

Question 11

What is the primary chemical constituent of 'marsh gas' produced by the anaerobic decomposition of organic matter in swamps and marshlands?

Accepted Answer

मेथेन ($\mathrm{CH_4}$)

Answer

एथेन ($\mathrm{C_2H_6}$)

Answer

कार्बन मोनोऑक्साइड ($\mathrm{CO}$)

Answer

हाइड्रोजन सल्फाइड ($\mathrm{H_2S}$)

Question 12

Which of the following solvents practically does NOT exhibit auto-ionization (self-ionization)?

Accepted Answer

एथिल ऐल्कोहॉल ($\mathrm{C_2H_5OH}$)

Answer

जल ($\mathrm{H_2O}$)

Answer

द्रव अमोनिया ($\mathrm{NH_3}$)

Answer

हाइड्रोजन फ्लोराइड ($\mathrm{HF}$)

Question 13

What is the hybridisation and geometry of the manganese ion ($\mathrm{Mn^{2+}}$) in the complex ion $[\mathrm{MnCl_4}]^{2-}$?

Accepted Answer

$sp^3$ (चतुष्फलकीय / Tetrahedral)

Answer

$dsp^2$ (वर्ग समतलीय / Square planar)

Answer

$d^3s$ (चतुष्फलकीय / Tetrahedral)

Answer

$sp^3d$ (त्रिकोणीय द्विपिरैमिडीय / Trigonal bipyramidal)

Question 14

According to Crystal Field Theory and Valence Bond Theory, what are the geometry and magnetic property respectively of the complex ion $[\mathrm{Ni(CN)_4}]^{2-}$?

Accepted Answer

वर्ग समतलीय और प्रतिचुंबकीय / Square planar and diamagnetic

Answer

चतुष्फलकीय और अनुचुंबकीय / Tetrahedral and paramagnetic

Answer

वर्ग समतलीय और अनुचुंबकीय / Square planar and paramagnetic

Answer

चतुष्फलकीय और प्रतिचुंबकीय / Tetrahedral and diamagnetic

Question 15

Which of the following complexes is an example of an 'outer orbital' (high-spin) complex?

Accepted Answer

$[\mathrm{FeF_6}]^{3-}$

Answer

$[\mathrm{Fe(CN)_6}]^{3-}$

Answer

$[\mathrm{Co(NH_3)_6}]^{3+}$

Answer

$[\mathrm{Cr(CN)_6}]^{3-}$

Question 16

In an octahedral crystal field, what are the magnitudes of Crystal Field Stabilization Energy (CFSE) for a $d^4$ metal ion in a weak ligand field (high-spin) and a strong ligand field (low-spin) respectively?

Accepted Answer

$-0.6\Delta_o$ और $-1.6\Delta_o + P$

Answer

$-1.6\Delta_o$ और $-0.6\Delta_o + P$

Answer

$-1.2\Delta_o$ और $-2.0\Delta_o + 2P$

Answer

$-0.4\Delta_o$ और $-1.2\Delta_o + P$

Question 17

What is the hybridisation of the sulfur atom in sulfur hexafluoride ($\mathrm{SF_6}$) and what is the bond angle between all adjacent $\mathrm{F-S-F}$ bonds?

Accepted Answer

$sp^3d^2$ संकरण तथा $90^\circ$ बंध कोण / $sp^3d^2$ hybridisation and $90^\circ$ bond angle

Answer

$sp^3d$ संकरण तथा $120^\circ$ और $90^\circ$ बंध कोण / $sp^3d$ hybridisation and $120^\circ, 90^\circ$ bond angles

Answer

$sp^3d^3$ संकरण तथा $72^\circ$ बंध कोण / $sp^3d^3$ hybridisation and $72^\circ$ bond angle

Answer

$dsp^2$ संकरण तथा $90^\circ$ बंध कोण / $dsp^2$ hybridisation and $90^\circ$ bond angle

Question 18

In which of the following hydrocarbon molecules do the carbon atoms exhibit $sp$-hybridisation?

Accepted Answer

एथाइन (एसीटिलीन, $\mathrm{C_2H_2}$)

Answer

एथीन (एथिलीन, $\mathrm{C_2H_4}$)

Answer

एथेन ($\mathrm{C_2H_6}$)

Answer

मेथेन ($\mathrm{CH_4}$)

Question 19

Among the following interhalogen compounds, which one is NOT known to exist?

Accepted Answer

$\mathrm{ICl_5}$

Answer

$\mathrm{IF_5}$

Answer

$\mathrm{BrF_5}$

Answer

$\mathrm{ClF_3}$

Question 20

Which element in the first transition series ($3d$-series) exhibits the highest oxidation state ($+7$)?

Accepted Answer

मैंगनीज ($\mathrm{Mn}$)

Answer

क्रोमियम ($\mathrm{Cr}$)

Answer

आयरन ($\mathrm{Fe}$)

Answer

वैनेडियम ($\mathrm{V}$)

Question 21

Which of the following transition metal ions is diamagnetic ($\mu = 0$) in nature?

Accepted Answer

$\mathrm{Zn^{2+}}$

Answer

$\mathrm{Cu^{2+}}$

Answer

$\mathrm{Fe^{2+}}$

Answer

$\mathrm{Ni^{2+}}$

Question 22

Why does an aqueous solution of ferric chloride ($\mathrm{FeCl_3}$) exhibit an acidic reaction toward litmus?

Accepted Answer

$\mathrm{Fe^{3+}}$ आयन के धनायनिक जल-अपघटन (cationic hydrolysis) द्वारा $\mathrm{H^+}$ आयन मुक्त होने के कारण / Due to cationic hydrolysis of $\mathrm{Fe^{3+}}$ releasing $\mathrm{H^+}$ ions

Answer

क्लोराइड आयन ($\mathrm{Cl^-}$) के ऋणायनिक जल-अपघटन द्वारा $\mathrm{OH^-}$ मुक्त होने के कारण / Due to anionic hydrolysis of $\mathrm{Cl^-}$ releasing $\mathrm{OH^-}$ ions

Answer

विलयन में अघुलित मुक्त $\mathrm{HCl}$ गैस घुली होने के कारण / Due to presence of unreacted dissolved $\mathrm{HCl}$ gas

Answer

यह एक दुर्बल अम्ल और प्रबल क्षारक का लवण है / Because it is a salt of a weak acid and a strong base

Question 23

Wilkinson's catalyst $\mathbf{[\mathrm{RhCl(PPh_3)_3}]}$ is widely utilized as a homogeneous catalyst for which important chemical transformation?

Accepted Answer

ऐल्कीनों और ऐल्काइनों का समांगी हाइड्रोजनीकरण / Homogeneous hydrogenation of alkenes and alkynes

Answer

ऐल्कोहॉलों का कीटोन में ऑक्सीकरण / Oxidation of alcohols to ketones

Answer

ऐल्कीनों का बहुलकीकरण / Polymerization of alkenes

Answer

ऐरोमैटिक हाइड्रोकार्बनों का नाइट्रीकरण / Nitration of aromatic hydrocarbons

Question 24

In analytical chemistry, which specific organic reagent is used for the gravimetric determination of zirconium(IV) ions ($\mathrm{Zr^{4+}}$)?

Accepted Answer

मैंडेलिक अम्ल (Mandelic acid)

Answer

डाइमेथिलग्लाइऑक्सिम (DMG)

Answer

क्यूप्रॉन (Cupron)

Answer

EDTA

Question 25

Which of the following statements is correct regarding the mechanism and stereochemical outcome of a bimolecular nucleophilic substitution ($\mathrm{S_N2}$) reaction?

Accepted Answer

यह एक संसृत (concerted) एक-पदीय अभिक्रिया है जिसमें विन्यास का पूर्ण प्रतिलोमन (Walden inversion) होता है / It is a concerted single-step reaction that proceeds with complete inversion of configuration (Walden inversion)

Answer

यह मध्यवर्ती कार्बोकैटायन के माध्यम से होती है और रेसिमीकरण (racemization) देती है / It proceeds through an intermediate carbocation and yields racemization

Answer

इसमें नाभिकरागी छोड़ने वाले समूह के समान दिशा से आक्रमण करता है जिससे विन्यास का प्रतिधारण (retention) होता है / The nucleophile attacks from the front side causing retention of configuration

Answer

यह अभिक्रिया कार्बन कंकाल के तीव्र पुनर्विन्यास (rearrangement) के साथ संपन्न होती है / The reaction proceeds with rapid carbocation rearrangement

Question 26

In the following chemical reaction sequence, what is the final product 'B'?$$\mathbf{R-COCl \xrightarrow{CH_2N_2} A \xrightarrow{H_2O, \,\Delta, \,Ag_2O} B}$$

Accepted Answer

$\mathrm{R-CH_2-COOH}$ (उच्चतर कार्बोक्सिलिक अम्ल / Homologous carboxylic acid)

Answer

$\mathrm{R-CO-CH_3}$ (मेथिल कीटोन / Methyl ketone)

Answer

$\mathrm{R-CONH_2}$ (एमाइड / Amide)

Answer

$\mathrm{R-COOH}$ (समान कार्बन वाला अम्ल / Parent carboxylic acid)

Question 27

Upon acid hydrolysis of diethyl malonate (malonic ester) followed by heating the resulting product at $\approx 150-200^\circ	ext{C}$, what is the primary product formed?

Accepted Answer

एसिटिक अम्ल ($\mathrm{CH_3COOH}$)

Answer

फॉर्मिक अम्ल ($\mathrm{HCOOH}$)

Answer

सक्सीनिक अम्ल ($\mathbf{\mathrm{HOOC-CH_2-CH_2-COOH}}$)

Answer

एथिल एसीटेट ($\mathrm{CH_3COOC_2H_5}$)

Question 28

When chlorine gas is bubbled through boiling toluene in the absence of Lewis acids, what is the major organic product formed after exhaustive side-chain substitution?

Accepted Answer

बेंज़ोट्राइक्लोराइड ($\mathrm{C_6H_5CCl_3}$)

Answer

$o$- और $p$-क्लोरोटॉलूईन का मिश्रण / Mixture of $o$- and $p$-chlorotoluene

Answer

बेंजिल क्लोराइड ($\mathrm{C_6H_5CH_2Cl}$)

Answer

हेक्साक्लोरोसाइक्लोहेक्सेन (BHC)

Question 29

Among the following carboxylic acids, which one is the strongest acid (lowest $\mathrm{p}K_a$ value)?

Accepted Answer

फॉर्मिक अम्ल ($\mathrm{HCOOH}$)

Answer

एसिटिक अम्ल ($\mathrm{CH_3COOH}$)

Answer

प्रोपियोनिक अम्ल ($\mathrm{CH_3CH_2COOH}$)

Answer

स्टीयरिक अम्ल ($\mathrm{C_{17}H_{35}COOH}$)

Question 30

Among phenol and the isomeric cresols, which compound exhibits the highest acidity (lowest $\mathrm{p}K_a$)?

Accepted Answer

फीनॉल ($\mathrm{C_6H_5OH}$)

Answer

$o$-क्रीसॉल ($2$-मेथिलफीनॉल)

Answer

$m$-क्रीसॉल ($3$-मेथिलफीनॉल)

Answer

$p$-क्रीसॉल ($4$-मेथिलफीनॉल)

Question 31

Which of the following nitrogen-containing organic compounds is the most basic?

Accepted Answer

बेंजिलऐमीन ($\mathrm{C_6H_5CH_2NH_2}$)

Answer

एनीलीन ($\mathrm{C_6H_5NH_2}$)

Answer

एसिटानिलाइड ($\mathrm{C_6H_5NHCOCH_3}$)

Answer

$p$-नाइट्रोएनीलीन ($\mathrm{O_2N-C_6H_4-NH_2}$)

Question 32

When an alkyl halide is heated with a sodium alkoxide, an ether is formed via nucleophilic substitution. By what name is this reaction known?

Accepted Answer

विलियमसन ईथर संश्लेषण (Williamson ether synthesis)

Answer

कोल्बे वैद्युत-अपघटन (Kolbe electrolysis)

Answer

वुर्ट्ज़ अभिक्रिया (Wurtz reaction)

Answer

पर्किन अभिक्रिया (Perkin reaction)

Question 33

In the photochemical Paternò–Büchi reaction, what primary cyclic product is formed by the irradiation ($h
u$) of an alkene and a carbonyl compound?

Accepted Answer

ऑक्सीटेन (Oxetane - 4-सदस्यीय चक्रीय ईथर / 4-membered cyclic ether)

Answer

ऑक्सीरेन (Oxirane / Epoxide - 3-सदस्यीय चक्रीय ईथर)

Answer

डाइऑक्सेन (Dioxane - 6-सदस्यीय चक्रीय ईथर)

Answer

टेट्राहाइड्रोफ्यूरॉन (THF - 5-सदस्यीय चक्रीय ईथर)

Question 34

Which of the following polymers is NOT an example of an addition polymer, but is instead a condensation polymer?

Accepted Answer

टेरीलीन (डेक्रॉन / Terylene or Dacron)

Answer

पॉलीथीन (Polyethene)

Answer

पॉलीविनाइल क्लोराइड (PVC)

Answer

टेफ्लॉन (PTFE - Polytetrafluoroethene)

Question 35

Which natural organic dicarboxylic acid is primarily found in tamarind and grapes?

Accepted Answer

टार्टरिक अम्ल (Tartaric acid)

Answer

सिट्रिक अम्ल (Citric acid)

Answer

ऑक्सालिक अम्ल (Oxalic acid)

Answer

मैलिक अम्ल (Malic acid)

Question 36

What is the correct molecular formula of barbituric acid (the parent framework of sedative barbiturates) and from the condensation of which two compounds is it synthesized?

Accepted Answer

$\mathrm{C_4H_4N_2O_3}$; यूरिया और डाइएथिल मैलोनेट के संघनन से / $\mathrm{C_4H_4N_2O_3}$; by condensation of urea and diethyl malonate

Answer

$\mathrm{C_4H_6N_2O_2}$; थायूरिया और एसिटिक एनहाइड्राइड के संघनन से / $\mathrm{C_4H_6N_2O_2}$; by condensation of thiourea and acetic anhydride

Answer

$\mathrm{C_5H_6N_2O_3}$; यूरिया और सक्सीनिक अम्ल के संघनन से / $\mathrm{C_5H_6N_2O_3}$; by condensation of urea and succinic acid

Answer

$\mathrm{C_3H_4N_2O_2}$; यूरिया और ऑक्सालिक अम्ल के संघनन से / $\mathrm{C_3H_4N_2O_2}$; by condensation of urea and oxalic acid

Solutions PGT Chemistry MCQs with Answer

Solutions – PGT Chemistry MCQs with Answers

Solutions Class 12 Chemistry MCQs PDF

1. The molality of pure water is:

2. The number of moles of NaCl in 3 litres of 3M solution is:

3. 4 L of 0.02 M NaCl is diluted by adding 1 L water. What is the new molarity?

4. Low oxygen concentration in blood at high altitudes is due to:

5. Which mixture shows a positive deviation from Raoult’s law?

6. Which solution has the highest boiling point?

7. Depression in freezing point of 0.01 M MgCl₂ compared to 0.01 M glucose is:

8. A mango shrivels in concentrated salt solution because:

9. Which statement is false?

10. Henry’s constant (KH) is:

11. Van’t Hoff factor i for NaCl solutions (A: 0.1M, B: 0.01M, C: 0.001M):

12. Urea solution isotonic with 5% solute. Molar mass of solute = ?

13. Volume of conc. H₂SO₄ (98%, d = 1.84 g/cm³) to make 1L 0.1M solution:

14. Mole fraction of solute in 1 m aqueous solution:

15. 1 mole benzene + 1 mole toluene. Vapour pressure of benzene = 12.8 kPa; toluene = 3.85 kPa. Vapour phase will contain:

16. Boiling point of a solution with 6.5 g solute in 100 g water. (Kb = 0.52):

17. Which is incorrect for an ideal solution?

18. If molality is doubled, Kf will be:

19. 10% glucose shows 16.4 atm osmotic pressure. Temperature is: (R = 0.082)

20. Which has highest freezing point?

21. Which statements are correct? (Multiple correct)

22. Benzoic acid in benzene:

Final Thoughts

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