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2025 34 questions

Q612025 · 24 Jan 2025 · Shift 2
Which of the following mixing of 1 M base and 1 M acid leads to the largest increase in temperature?
1. A.50 mL HCl and 20 mL NaOH
2. B.30 mL HCl and 30 mL NaOH
3. C.45 mL $C H_{3} COOH$ and 25 mL NaOH
4. D.30 mL $C H_{3} COOH$ and 30 mL NaOH
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Answer: B
Q702025 · 24 Jan 2025 · Shift 2
Identify correct statement/s : (A) $- OC H_{3}$ and $- NHCOC H_{3}$ are activating group. (B) $- CN$ and -OH are meta directing group. (C) -CN and $- S O_{3} H$ are meta directing group. (D) Activating groups act as ortho - and para directing groups. (E) Halides are activating groups. Choose the correct answer from the options given below :
1. A.(A), (C) and (D) only
2. B.(A), (B) and (E) only
3. C.(A) and (C) only
4. D.(A) only
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Answer: A
Q742025 · 24 Jan 2025 · Shift 2· Numerical answer
The observed and normal molar masses of compound $M X_{2}$ are $65.6$ and $164$ respectively. The percent degree of ionisation of $M X_{2}$ is ____%. (Nearest integer)
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Answer: 75
Q532025 · 23 Jan 2025 · Shift 2
Match List - I with List - II | | List - I | | List - II | |---|---|---|---| | (A) | Bronze | (I) | Cu, Ni | | (B) | Brass | (II) | Fe, Cr, Ni, C | | (C) | UK silver coin | (III) | Cu, Zn | | (D) | Stainless steel | (IV) | Cu, Sn | Choose the correct answer from the options given below :
1. A.(A)-(IV), (B)-(II), (C)-(III), (D)-(I)
2. B.(A)-(IV), (B)-(III), (C)-(I), (D)-(II)
3. C.(A)-(III), (B)-(I), (C)-(IV), (D)-(II)
4. D.(A)-(III), (B)-(IV), (C)-(II), (D)-(I)
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Answer: B
Q672025 · 23 Jan 2025 · Shift 2
1. A.(C) < (D) < (B) < (A)
2. B.(D) < (A) < (B) < (C)
3. C.(D) < (B) < (A) < (C)
4. D.(C) < (B) < (A) < (D)
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Answer: B
Q602025 · 22 Jan 2025 · Shift 1
A liquid when kept inside a thermally insulated closed vessel at $2 5^{\circ} C$ was mechanically stirred from outside. What will be the correct option for the following thermodynamic parameters ?
1. A. $Δ U = 0, q < 0, w > 0$
2. B. $Δ U > 0, q = 0, w > 0$
3. C. $Δ U = 0, q = 0, w = 0$
4. D. $Δ U < 0, q = 0, w > 0$
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Answer: B
Q682025 · 22 Jan 2025 · Shift 1
Radius of the first excited state of Helium ion is given as : $a_{0} \to$ radius of first stationary state of hydrogen atom.
1. A. $r = \frac{a _{0}}{4}$
2. B. $r = 2 a_{0}$
3. C. $r = 4 a_{0}$
4. D. $r = \frac{a _{0}}{2}$
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Answer: B
Q702025 · 22 Jan 2025 · Shift 1
Which of the following statement is not true for radioactive decay?
1. A.Half life is $ln 2$ times of $\frac{1}{rate constant}$ .
2. B.Decay constant increases with increase in temperature.
3. C.Decay constant does not depend upon temperature.
4. D.Amount of radioactive substance remained after three half lives is $\frac{1}{8} th$ of original amount.
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Answer: B
Q732025 · 22 Jan 2025 · Shift 1· Numerical answer
Some $CO_{2}$ gas was kept in a sealed container at a pressure of $1 atm$ and at $273 K$ . This entire amount of $CO_{2}$ gas was later passed through an aqueous solution of $Ca (OH)_{2}$ . The excess unreacted $Ca (OH)_{2}$ was later neutralized with $0.1 M$ of $40 mL HCl$ . If the volume of the sealed container of $CO_{2}$ was $x$ , then $x$ is _________ $cm^{3}$ (nearest integer). [Given : The entire amount of $CO_{2} (g)$ reacted with exactly half the initial amount of $Ca (OH)_{2}$ present in the aqueous solution.]
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Answer: 45