SPSC CHEMISTRY 25 YEARS PAST PAPERS
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چار آپشن میں سے کسی ایک پر کلک کرنے سے جواب سرخ ہو جائے گا۔
ٹیفلون کس مونومر کا پولیمر ہے؟
- Ethylene
- Propylene
- Tetrafluoroethylene
- None of these
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Explanation
- The chemical formula for tetrafluoroethylene is C₂F₄.
Additional information:
- Chemical name: Polytetrafluoroethylene (PTFE)
- Monomer: Tetrafluoroethylene
- Notable property: Highly non-stick surface, often used in cooking utensils
Last verified on 14-11-2026
نیوٹرون کس نے دریافت کیا؟
- Rutherford
- Thomson
- J Perrin
- Chadwick
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Explanation
- Sir James Chadwick discovered the neutron in 1932.
- He was a British physicist.
- His discovery completed the basic picture of the atomic nucleus.
- He received the Nobel Prize in Physics in 1935 for this discovery.
Additional information:
- J. J. Thomson – Electron (1897)
- Ernest Rutherford – Atomic nucleus (1911) and Proton (1917)
Last updated by NA on 05-11-2026
اینٹی پولیو ویکسین کی پروسیسنگ میں مندرجہ ذیل میں سے کون سا کیمیکل استعمال ہوتا ہے؟
- Formaldehyde
- Ethyl acetate
- Methanol
- None of these
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Explanation
Formaldehyde is used to inactivate the poliovirus in the production of the inactivated polio vaccine (IPV).This ensures the virus is non-infectious while still triggering an immune response.Last verified on 02-11-2026
ہائیڈروجن کا کون سا آاسوٹوپ تابکار ہے؟
- Tritium
- Protium
- Deuterium
- None of these
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Explanation
- Tritium (³H) is the radioactive isotope of hydrogen.
- It undergoes beta (β) decay and changes into Helium-3.
Additional information:
- Hydrogen Isotopes: 3 (Protium, Deuterium, Tritium)
- Protium (¹H): 1 proton, 0 neutrons (Stable)
- Deuterium (²H): 1 proton, 1 neutron (Stable)
- Tritium (³H): 1 proton, 2 neutrons (Radioactive)
- Half-life of Tritium: Approximately 12.3 years
Last verified on 04-08-2026
وہ کیمیائی مرکبات جو پروٹین کی نوعیت کے ہوتے ہیں اور جانداروں کے خلیوں میں بنتے ہیں، کیا کہلاتے ہیں؟
- Vitamins
- Hormones
- Enzymes
- None of these
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Explanation
- Enzymes are protein-based chemical compounds produced in the cells of living organisms.
- They act as biological catalysts, speeding up chemical reactions.
- Enzymes are essential for digestion, metabolism, and energy production.
Verified & Updated
- 0.86
- 1.76
- 0.57
- 5.16
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Explanation
Look at the reaction: N₂ + 3H₂ → 2NH₃
For every 1 N₂ that reacts, 3 H₂ react.
So H₂ gets used 3 times faster than N₂.
Given: H₂ is used at 1.72 mol L⁻¹ h⁻¹
Then N₂ is used 3x slower:
Rate of N₂ = 1.72 ÷ 3 = 0.57 mol L⁻¹ h⁻¹
Last verified on 05-06-2026
طویل ہائیڈروکاربن چین والے کاربوکسلک ایسڈ ہوتے ہیں۔ _____
- Fats
- Lipids
- Fatty acids
- Proteins
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Explanation
- Fatty acids are carboxylic acids with long hydrocarbon chains.
- They contain a carboxyl group (–COOH) attached to a long alkyl chain.
- They are major components of fats and oils.
Last verified on 05-06-2026
ثانوی الکوحل کے آکسیڈیشن سے کیا بنتا ہے؟
- Aldehydes
- Ketones
- Ethers
- Esters
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Explanation
- Oxidation of secondary alcohols produces ketones.
- Secondary alcohols have –OH group attached to a carbon bonded with two other carbons.
- During oxidation, hydrogen is removed and a carbonyl (C=O) group is formed.
Additional information:
- Primary alcohol → Aldehyde → Acid
- Secondary alcohol → Ketone (stops here)
- Tertiary alcohol → No easy oxidation
Last verified on 05-06-2026
کاربنک ایسڈ میں ہر آکسیجن کے بانڈ بنانے میں کاربن کے کون سے ہائبرڈ اوربٹلز استعمال ہوتے ہیں؟
- sp³
- sp²
- sp
- None of these
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Explanation
- sp² hybridization is used by each oxygen in carbonic acid (H₂CO₃).
- In H₂CO₃, carbon is bonded to three oxygen atoms.
- Each oxygen forms sigma bonds and has resonance involvement.
- Oxygen adopts sp² hybrid orbitals for proper bonding geometry.
Last verified on 05-06-2026
وہ عناصر جن کا نیوکلیئر اسپن صفر ہو انہیں براہ راست کس تکنیک سے معلوم نہیں کیا جا سکتا؟
- NMR spectroscopy
- Atomic Absorption spectroscopy
- IR spectroscopy
- HPLC
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Explanation
- NMR (Nuclear Magnetic Resonance) spectroscopy depends on nuclear spin.
- Only nuclei with non-zero spin give NMR signals.
- Elements with zero nuclear spin are NMR inactive.
- Therefore, they cannot be directly detected by NMR spectroscopy.
Last verified on 05-06-2026