रसायन विज्ञान (Chemistry) – Chemistry MCQ
रसायन विज्ञान (Chemistry) – CEE प्रवेश
Chemistry · Medical Entrance (CEE) – Physics, Chemistry, Biology & MAT · ४१० प्रश्न
४१० प्रश्न उपलब्ध। मोड छान्नुहोस्:
रसायन विज्ञान (Chemistry): प्रश्न र उत्तर
सही लागेको विकल्पमा थिच्नुहोस्। सही भए हरियो, गलत भए रातो देखिन्छ; ३ सेकेन्डपछि सही उत्तर र व्याख्या देखिन्छ।
सही: ० / ०
-
The total number of orbitals in the shell with principal quantum number n = 3 is:
सही उत्तर: क) 9
The number of orbitals in a shell is n² = 9 (one 3s, three 3p, five 3d). 18 is the maximum number of electrons (2n²), not orbitals.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The maximum number of electrons that can be accommodated in a subshell with l = 2 is:
सही उत्तर: ख) 10
For l = 2 (d subshell), there are 2l + 1 = 5 orbitals, each holding 2 electrons, i.e. 10 electrons. 14 is for the f subshell (l = 3).
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
A gas at 27 °C is heated to 327 °C at constant pressure. Its volume becomes:
सही उत्तर: घ) Twice the original
Charles' law uses absolute temperature: 300 K → 600 K, so the volume doubles. Using °C (27 → 327) wrongly suggests about a 12-fold increase.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The ratio of the rates of diffusion of H₂ and O₂ under identical conditions is:
सही उत्तर: क) 4 : 1
By Graham's law, rate ∝ 1/√M, so r(H₂)/r(O₂) = √(32/2) = 4. 16 : 1 is the ratio of molar masses, not rates.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
At constant temperature, if the pressure of a fixed mass of gas is doubled, its volume becomes:
सही उत्तर: क) Half
By Boyle's law, PV = constant at fixed temperature, so doubling P halves V. Volume doubles with temperature (in kelvin) at constant pressure, which is Charles' law.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
4 g of H₂ reacts with 16 g of O₂ to form water. The mass of water formed is:
सही उत्तर: घ) 18 g
4 g H₂ = 2 mol and 16 g O₂ = 0.5 mol; 2H₂ + O₂ → 2H₂O, so O₂ is limiting and gives 1 mol (18 g) of water. 36 g would assume H₂ fully reacts, but there is not enough oxygen.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The percentage of nitrogen by mass in urea, CO(NH₂)₂, is approximately:
सही उत्तर: ख) 46.7%
Molar mass of urea is 60 g/mol and it contains 28 g of nitrogen, so %N = 28/60 × 100 ≈ 46.7%. This high nitrogen content makes urea a popular fertilizer.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The equivalent mass of H₂SO₄ (molar mass 98 g/mol) is:
सही उत्तर: ग) 49
Equivalent mass = molar mass / basicity = 98/2 = 49. 98 would be correct only if the acid were monobasic.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The normality of 0.5 M H₂SO₄ solution is:
सही उत्तर: क) 1 N
H₂SO₄ is dibasic (n-factor 2), so N = M × 2 = 1 N. Normality equals molarity only for monobasic acids like HCl.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
-
The volume occupied by 2 g of hydrogen gas at STP (taking molar volume as 22.4 L) is:
सही उत्तर: ग) 22.4 L
2 g of H₂ is 1 mol (molar mass 2 g/mol), which occupies 22.4 L at STP. 44.8 L would result from wrongly taking the molar mass of H₂ as 1 g/mol.
💬 टिप्पणी / गल्ती रिपोर्ट (०)
यी अभ्यास प्रश्न हुन्, आधिकारिक प्रश्न होइनन्। पाठ्यक्रम, विज्ञापन र नतिजाका लागि सम्बन्धित निकायको आधिकारिक वेबसाइट हेर्नुहोस्। उत्तरमा गल्ती भेटे प्रश्नमुनिको "टिप्पणी / गल्ती रिपोर्ट" मा लेख्नुहोस्।
नमस्ते! पाठ्यक्रम, सामान्य ज्ञान, भाषा परीक्षा वा कुनै प्रश्नको उत्तर बुझ्न सोध्नुहोस्।
AI ले गल्ती गर्न सक्छ। महत्वपूर्ण कुरा आधिकारिक स्रोतमा जाँच्नुहोस्।