SPSC 25 YEARS PAST PAPERS 2001 TO 2026
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چار آپشن میں سے کسی ایک پر کلک کرنے سے جواب سرخ ہو جائے گا۔
کھلی ہوا میں کرومیم ٹو کمپلیکس کا رنگ _______ میں تبدیل ہوتا ہے؟
- Violet
- Green
- Pink
- None of these
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Explanation
Chromium(II) complexes are easily oxidized in open air to Chromium(III), which often appears green.The color change occurs due to oxidation and ligand exchange reactions.
ایڈٹا کو کون سا لیگینڈ کہا جاتا ہے؟
- Polydentate
- Bidentate
- Tridentate
- None of these
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Explanation
EDTA (Ethylenediaminetetraacetic acid) is a polydentate ligand.Because it can bind to a metal ion through six donor atoms.It forms stable chelates by coordinating through oxygen and nitrogen atoms.
فضائی آلودگی ______ کی وجہ سے ہے؟
- Hydrocarbons
- Water vapours
- Carbon dioxide
- None of these
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Explanation
Hydrocarbons contribute to air pollution by forming smog and reacting with nitrogen oxides.They come from vehicle emissions, industrial processes, and burning fossil fuels.
پوٹاشیم اور کیلشیم سلیکیٹس کا مرکب _____ تشکیل دیا گیا ہے؟
- Soft glass
- Flint glass
- Hard glass
- None of these
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Explanation
A mixture of potassium and calcium silicates forms hard glass.This is known for its high resistance to heat and chemicals.It is stronger than soft glass due to its composition.
- Dehydration
- Evaporation
- Filtration
- None of these
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Explanation
Ignition of Fe(OH)₃ removes water (H₂O), converting it to Fe₂O₃.This process is called dehydration, as it involves the loss of water molecules.
سلفورک ایسڈ ایک _______ ایسڈ ہے۔
- Lewis
- Oxoacid
- Protons
- None of these
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Explanation
Sulfuric acid (H₂SO₄) is an oxoacid because it contains oxygen along with hydrogen and sulfur.It donates protons (H⁺), but its classification is based on the presence of oxygen.
ٹھوس مادہ کے اعتدال پسند خشک ہونے کے لئے سب سے موزوں درجہ حرارت ______ ہے؟
- 120°C
- 220°C
- 320°C
- None of these
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Explanation
Moderate drying of solid substances is typically done at 120°C to remove moisture without decomposition.Higher temperatures may cause degradation of heat-sensitive materials.
ایک کمپلیکس کا ایک واحد حل جس میں مساوی مقدار میں دو آپٹیکل آئیسومرز پر مشتمل ہے اسے _____ مرکب کہا جاتا ہے۔
- Racemic
- Reactor
- Acid-base
- None of these
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Explanation
A solution containing equal amounts of two optical isomers is called a racemic mixture.Racemic mixtures are optically inactive because the rotations cancel each other out.
- Inner
- Outer
- Octahedral
- None of these
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Explanation
Octahedral complexes in which the central atom is d2sp3 are called inner orbital octahedral complexes.
While octahedral complexes in which the central atom is sp3d2 are called outer orbital octahedral complexes.
- 3.33 m
- 3.33 mn
- 3.33 mm
- None of these
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Explanation
Using the formula: λ = c / f (where λ = wavelength, c = speed of light, and f = frequency)
λ = (3 × 10^8 m/s) / (90 × 10^6 Hz) ≈ 3.33 m.
