Karnataka 1st PUC Second Test Question Paper 2025 Chemistry

Government of Karnataka
Karnataka Secondary Education Examination Board

Question Papers
Quarterly Exam

SECOND QUARTERLY TEST DECEMBER 2025
CLASS :IPUC SUBJECT: CHEMISTRY(34) Max. Marks : 35
Time:1 Hr. 30 Mins.
PART-A
Select the correct option from the given choices : 7x1=7
1) The oxidation number of manganese in Mn,0, is
a) +3 b) +7 c) +5 d) +6
2) Which statement is wrong?
a) Oxidation number of oxygen in peroxide is +1
b) Oxidation number of oxygen in oxygen difluoride is + 2
c) Oxidation number of oxygenin superoxide is -
d) Oxidation number of oxygen in dioxgen difluoride is +1
3) Conjugate base of Bronsted acid H,0 and HF is
a) H,0* &H,F* respectively b) OH &H,F* respectively
c) H,0* F respectively d) OH &F respectively
4) If the equilibrium constant of H,tI,n2HI, is K, the equilibrium constant of
1
;H) ) H willbe
1
c) K?
a) ;K b) K d) K'
5) Which of the following salts will give highest pH in water ?
a) KCi b) NaCl c) Na,CO, d) all of these
6 Match the Column -I with Column II & choose the appropriate answer
Column-I Column-II
A) nbutane ’2 methyl propane i)Free radical substitution
hv
B) CH,+Cl, ’ CH, CI ii) Wurtz reaction
C) R-COONA Soda
lime
R-H i) Isomerisation
D) R-X+ Na ether R-R iv) Decarboxylation
a) (A)’(i),(B)’(i), (C)’(iv), (D)’()
b) (A)’(i), (B)’(iv),(C)’(), (D)-’(üi)
c)(A)’(0), (B)’(), (C)’(iv), (D)’(i)
d) (A)>(iv), (B)’(),(C)’(ii), (D)’(i)
7) When propene is subjected to ozonolysis, what is the end product?
a) Formic acid b)Ethanal c) Oxalic acid d) Glucose
II Fillin the blanks by choosing appropriate word from those given in brackets:3x1=3
[oxidizing agent, remains unchanged, reducing agent, soda lime]
8) On adding a catalyst toa reaction, the equilibrium constant
9) Areagent which can increase the oxidation number of an element in another substance is
called
10) is a mixture of sodium hydroxide and calcium oxide.
(P.T.0)

-2
PART-B
II Answer any THREE of the following questions. Each question carries 2 marks:
3x2=6
11) What are acids and bases according to Arrhenius theory ?
12) Show that pH t pOH =14.
13) In the reaction 2H,0, ’ 2H,O+0,. Identify the species in which oxygen exhibit-1oxidation
state and mention the type of reaction.
14) Explain decarboxylation reaction with an example.
15) What are ortho and para directing groups ? Give an example.
PART-C
V Answer any ONE of the following questions. Each question carries 3 marks:1x3=3
16) a) What are non-metal displacement reaction ? Give an example. (2)
b) Write the formula of Chromium (III) Oxide. (1)
17) Balance the following redox reaction by oxidation number method.
Cr,0; +So ’Cr +S0, + H,0(Acidmedium) (3)
Answer any ONE of the following questions. Each question carries 3 marks:1x3=3
18) a) Explain common ion effect with an example. (2)
b) What is the effect of catalyst on equilibrium? (1)
19) Describe the effect of
a) Addition of H, (1)
b)Increase in temperature (1)
c) Increase in pressure (1)
On the equilibrium of the reaction :
Nag) +3H(g) 2NH,); AH-92.38 kJ moll
Using Le-Chatelier's principle.
PART-D
VI Answer any TWOof the following questions. Each question carries 5 marks: 2x5=10
20) a) How to prepare Ethyne from calcium carbide ? Write the chemical equation. (3)
b) Give two tests for unsaturation. (2)
21) a) State Huckel Rule. (2)
b) () Complete the equation
OH
(2)
+ Zn A
CH Red hot iron tube
c) 3 n
CH
873 K
(1)
22) a) Explain the mechanisn of nitration of Benzene. (3)
b) Namne the product formed when benzene is treated with excess of chlorine in presence
of anhydrous AlCL, and also give the equation. (2)
PART-E
VI Answer any ONE of the following questions. Each question carries 3 marks:1x3-=3
23) The following concentrations were obtained for the formation of NH, from N, & H, at
equilibrium at S00K. (N,=1.5x 10² M[H,]=3.0 x10* Mand [NH,]=1.2x 10* M.
Calculate equilibriunm constant. 3)
24) The pk, of acetic acid and pk, of ammonium hydroxide are 4.76 and 4.75 respectively.
Calculate the pH of ammonium acetate solution. (3)

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