Chemistry: Hydrogen and its compound Questions for Railway & SSC CGL Exam 2018: 30th June

Railway Board offers opulent and revered job posts to its aspirants. And it is not every year that we get the notification from Railway offering a good number of vacant seats to the multitude aspirants. But the current year 2018 brought a pleasant surprise with almost 90,000 seats to be filled by the valid candidates. Opportunity is here but you have to welcome it with a provident strategy. The exam will be conducted in the month of May 2018. 

रेलवे बोर्ड अपने उम्मीदवारों के लिए भव्य और प्रतिष्ठित कार्य पदों की पेशकश करता है. और हर साल ऐसा नहीं होता है कि हमें रेलवे की ओर से अधिसूचना मिलती है. लेकिन वर्तमान वर्ष 2018 आपके लिए बहुत सुखद वर्ष है क्योंकि इसमें लगभग 90,000 सीटों को वैध उम्मीदवारों द्वारा भरा जाएगा. आपके पास बहुत अच्छा अवसर है और आपको इसे एक बेहतर रणनीति से प्राप्त करना होगा. परीक्षा मई 2018 के महीने में आयोजित की जायेगी.

Q1. An element X has four electrons in its outermost orbit. What will be the formula of its compounds with Hydrogen? 
एक तत्व X में इसकी बाहरी कक्षा में चार इलेक्ट्रॉन हैं. हाइड्रोजन के साथ इसके यौगिकों का सूत्र क्या होगा?
(a) X_4 H
(b) X_4 H_4
(c) XH_3
(d) XH_4
Show Answer
Sol. The compounds of element X which has four electrons in its outermost orbit will be XH4.

Q2. According to weight, the percentage of Hydrogen in water (H_2 O), is-
वजन के अनुसार, पानी में हाइड्रोजन का प्रतिशत (H2O), है?
(a) 44.45%
(b) 5.55%
(c) 88.89%
(d) 11.11%
Show Answer
Sol. Percentage of composition is the percent by mass of each element present in a compound.
In Water, H2O = 2 + 16 = 18 g/mol
Molecular weight of water 18.0152 grams
No. of Hydrogen atoms present in Water = 2
∴ Percentage of Hydrogen in water
= 2/18×100=11.11%

Q3. Burning of Hydrogen produces- 
हाइड्रोजन के जलने से क्या उत्पन्न होता है – 
(a) Oxygen  / ऑक्सीजन
(b) Ash  / राख
(c) Soil  / मृदा
(d) Water  / पानी
Show Answer
Sol. Hydrogen gas is highly flammable and burns in air at a very wide range of concentrations between 4% to 75% by volume. Hydrogen gas cannot burn in absence of air. But by burning with Oxygen it produces water.

Q4. Which one of the following fuels causes minimum air pollution? 
निम्नलिखित से कौन सा ईंधन न्यूनतम वायु प्रदूषण का कारण बनता है?
(a) Kerosene oil  /किरोसीन तेल
(b) Hydrogen /हाइड्रोजन
(c) Coal /  कोयला
(d) Diesel  / डीज़ल
Show Answer
Sol. Hydrogen is the purest combustion fuel. Water is generated from burning of Hydrogen. While coal, kerosene oil and diesel are known as fossil fuel or carbonic fuel which generates Carbon dioxide and many other harmful gases when it burns.

Q5. Heavy water is a type of- 
भारी पानी ________ का एक प्रकार है.
(a) Coolant / कूलेंट
(b) Moderator / मॉडरेटर
(c) Ore  / अयस्क
(d) Fuel  / ईंधन
Show Answer
Sol. Heavy water (D2O) Deuterium Oxide is used as a moderator and coolant in nuclear reactors because it slows down neutrons effectively and also has a low probability of absorption of neutrons. Deuterium is an isotope of Hydrogen which comprises both a neutron and a proton. D2O is a form of water which reacts with Oxygen to form Deuterium Oxide (O2O), also known as heavy water.

Q6. The chemical formula of Heavy Water is? 
भारी पानी का रासायनिक सूत्र क्या है ?
(a) H_2 O
(b) D_2 O
(c) H_2 CO_3
(d) H_2 S
Show Answer
 Sol. Heavy water is a form of water that contains a larger than normal amount of the hydrogen isotope       deuterium, rather than the common hydrogen-1 isotope that makes up most of the hydrogen in normal water. The chemical formula of Heavy Water is D2O.

Q7. Which of the following fuel material occurred naturally?
निम्नलिखित में से कौन सी ईंधन सामग्री स्वाभाविक रूप से हुई?
(a) U235
(b) Pu239
(c)  Pu241
(d) U-233
Show Answer
Sol. Uranium-235 is an isotope of uranium making up about 0.72% of natural uranium.

Q8. What is heavy water? 
भारी पानी क्या है? 
(a) Oxygen + Heavy Hydrogen / ऑक्सीजन + हैवी हाइड्रोजन
(b) Hydrogen + Oxygen / हाइड्रोजन + ऑक्सीजन
(c) Hydrogen + New Oxygen / हाइड्रोजन + न्यू ऑक्सीजन
(d) Heavy Hydrogen + Heavy Oxygen / हैवी हाइड्रोजन + हैवी ऑक्सीजन
Show Answer
Sol.  Oxygen+Heavy Hydrogen or deuterium

Q9. Heavy water is that water- 
भारी पानी वह पानी है -
(a) The temperature of which is kept constant at 4°C / जिसका तापमान 4 डिग्री सेल्सियस पर स्थिर रखा जाता है.
(b) In which insoluble salts of Calcium and Potassium are present / कैल्शियम और पोटेशियम के अघुलनशील लवण मौजूद हैं.
(c) In which isotopes takes place of Hydrogen / जिसमें समस्‍थानिक हाइड्रोजन की जगह होते है.
(d) In which isotopes takes place of Oxygen / जिसमें समस्‍थानिक ऑक्सीजन की जगह होते है.
Show Answer
Sol.Heavy water is that water In which isotopes takes place of Hydrogen.

Q10. Who among the following discovered heavy water? 
इनमे से भारी पानी किसके द्वारा खोजा गया था?
(a) Heinrich Hertz  /  हेनरिक हर्ट्ज
(b) H.C. Urey /  एच.सी. Urey
(c) G. Mendel  / जी मेंडेल
(d) Joseph Priestly / यूसुफ प्रीस्टली
Show Answer
S10. Ans.(b)
Sol. Harold Clayton Urey, an American Chemist discovered heavy water in 1931. He was awarded Nobel Prize in Chemistry in 1934 for this discovery.

Q11. Consider the following statements: 
निम्नलिखित कथनों को ध्यानपूर्वक पढ़िए.
Hard water is not suitable 
कठोर जल उपयुक्त नहीं है:
1. Drinking / पीने के लिए 
2. Washing clothes with soap / साबुन के साथ कपड़े धोने के लिए  
3. Use in boilers / बायलर में उपयोग करने के लिए 
4. Irrigating crops / फसलों की सिंचाई के लिए

Which of these statements are correct? 
इनमे से कौन सा कथन सत्य है ?
(a) 1 and 2 / 1 और 2
(b) 2 and 3   / 2 और 3
(c) 1, 2 and 4   / 1,2 और 4
(d) 1, 2, 3 and 4  / 1,2,3 और 4
Show Answer
Sol. Drinking water is described as “hard” due to the presence of highly dissolved minerals specifically sulphates of Calcium and Magnesium Chloride. It is very difficult to wash clothes with hard water as it requires more soap and leaves a messy scum that cannot be washed out easily. When hard water is boiled at home or in industries, it leaves deposits of Calcium and Magnesium salts. These deposits reduce the efficiency of boilers, kettles and pipes and can cause blockages and even burst of the boilers. If salt level increases in irrigation water, it becomes harder for lawns and landscape plant to take up water even though the soil is moist. Consequently, more salty water requires extra effort to irrigate.

Q12. Permanent hardness of water is due to- 
पानी की स्थायी कठोरता की वजह है:
(a) Chlorides and sulphates of Calcium and Magnesium / कैल्शियम और मैग्नेशियम के क्लोराइड और सल्फाट
(b) Calcium bicarbonate sulphates / कैल्शियम बिकारबोनेट सल्फ़ेट्स
(c) Magnesium bicarbonate  / मैग्नेशियम बाइकार्बोनेट
(d) Clorides of Silver and Potassium  / सिल्वर और पोटेशियम के क्लोराइड्स
Show Answer
Permanent hardness in water is hardness due to the presence of the chlorides  and sulphates of calcium and magnesium

Q13. The pH-value for water is-
पानी का pH-मान है - 
(a) Nearly zero / लगभग शून्य
(b) Nearly 7/ लगभग 7
(c) 5 or less than 5 /5 या 5 से कम
(d) 8.7 or more / 8.7 या अधिक
Show Answer
Sol. The pH value of pure water is 7. Pure water is neutral by nature. The solution with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline.

Q14. Water is a good solvent of ionic salts because- 
पानी आयनिक लवण का एक अच्छा विलायक है क्योंकि-
(a) It has a high boiling point  / इसका उच्च क्वथनांक है
(b) It has a high dipole moment / इसमें एक उच्च द्विध्रुव आघूर्ण है
(c) It has a high specific heat  / इसमें उच्च विशिष्ट आघूर्ण है
(d) It has no colour  / इसका  कोई रंग नहीं है
Show Answer
Sol. Water is a good solvent due to its polarity which can easily dissolve into polar compounds. Water dissolves ionic salts by hydrating their component ions. For example, water dissolves NaCl by hydrating and stabling the Na+ and Cl– ions.

Q15. Large quantities of drinking water is prepared from impure water by- 
अशुद्ध पानी से पीने के पानी की बड़ी मात्रा को किसके द्वारा तैयार किया जाता है -  
(a) Desalination  / डिसेलिनेशन
(b) Distillation  / आसवन
(c) Ion-exchange  / आयन विनिमय
(d) Decantation  / निस्तारण
Show Answer
Sol. Desalination is a process that removes minerals from saline water (Also refer to removal of salts and minerals). Seawater desalination has a very effective way of production of potable water for drinking and industries.



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