Chemistry Questions for Railway & SSC CGL Exam 2018: 19th July

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. 

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.

Q1. Pasteurization is related to:
पाश्चरराइजेशन _______ से संबंधित है:
(a) Sterilization of milk / दूध के विसंक्रमण
(b) Dehydration of milk /दूध के निर्जलीकरण
(c) Fermentation of milk /दूध के किण्वन
(d) Distillation of milk /दूध के आसवन
Show Answer
Sol. The Pasteurization is a process that kills microbes (mainly bacteria) in food and drinks such as milk and facilitates its preservation and safety. In this process, the milk is heated at about 63°C for 30 minutes or, alternatively at about 72°C for 15 seconds to ensure that any harmful bacteria is not alive. The process was invented by the French scientist Louis Pasteur. So it is called Pasteurization.

Q2. Which is the most abundant element after Oxygen in Earth crust?
पृथ्वी की परत पर ऑक्सीजन के बाद सबसे प्रचुर मात्रा में तत्व कौन सा है?
(a) Silicon / सिलिकॉन
(b) Carbon / कार्बन
(c) Sodium / सोडियम
(d) Chlorine /क्लोरीन
Show Answer
Sol. The most abundant element on earth’s surface after Oxygen is Silicon. The word ‘Silicon’ was taken from the Latin word silex. Silicon chips are used as a semiconductor in computers.

Q3. Which is the most reactive metal?
सबसे प्रतिक्रियाशील धातु कौन सी है?
(a) Sodium / सोडियम
(b) Calcium / कैल्शियम
(c) Iron / लोहा
(d) Potassium  / पोटैशियम
Show Answer
Sol. Potassium is the most reactive metal.
The reactivity series of the following elements is
Potassium (K)>Sodium (Na)>Calcium (Ca)>Iron (Fe)

Q4. Which one of the following is the hardest metal?
निम्न में से कौन सी सबसे कठोर धातु है?
(a) Gold/सोना
(b) Iron/आयरन
(c) Nickel / निकेल
(d) Tungsten /टंगस्टन
Show Answer
Sol. Tungsten is one of the hardest metals found in nature. Tungsten is often utilized to create hard alloys, such as high speed steel to increase protection against abrasion as well as improve electrical conductivity.

Q5. Chemically “Plaster of Paris” is:
"प्लास्टर ऑफ़ पेरिस" रासायनिक रूप से है:
(a) Calcium Sulphate /कैल्शियम सल्फेट
(b) Calcium Carbonate /कैल्शियम कार्बोनेट
(c) Calcium Oxide / कैल्शियम ऑक्साइड
(d) Calcium Oxalate /कैल्शियम ऑक्सालेट
Show Answer
Sol. A group of gypsum cement, essentially hemihydrated Calcium Sulphate (CaSO₄. 1/2H₂O), a white powder that forms a paste when it is mixed with water and then hardens into a solid used in making a cast, mould and sculpture.

Q6. Monazite is an ore of–
मोनाजाईट एक अयस्क है-
(a) Zirconium  /ज़िरकोनियम
(b) Thorium  /थोरियम
(c) Titanium / टाइटेनियम
(d) Iron / लोह
Show Answer
Sol. Monazite is an important ore for Thorium, Lanthanum and Cerium. India, Madagascar and South Africa have large deposits of monazite sands. The deposits in India are particularly rich in Monazite. Its extensive deposits are found in Southern India.

Q7. Which one of the following liquids is used in Thermometers?
निम्नलिखित में से कौन सा एक तरल थर्मामीटर में प्रयोग किया जाता है?
(a) Mercury/ पारा
(b) Water/ पानी
(c) Ether/ ईथर
(d) Benzene /बेंजीन
Show Answer
Sol. Mercury is a chemical element with the symbol (Hg). Mercury is used in thermometers due to its special properties. It can measure a wide range of temperatures from –40 to 356°C and up to 570°C under pressure in a liquid state. It expands regularly in proportional to the absolute temperature changes. A heavy, silvery d-block element, mercury is the only metallic element which is found in liquid state at standard conditions for temperature and pressure.

Q8. Out of the following which is not an alloy?
निम्नलिखित में से कौन सी एक मिश्र धातु नहीं है?
(a) Steel / स्टील
(b) Brass / पीतल
(c) Bronze / कांस्य
(d) Copper / कॉपर
Show Answer
Sol. Copper is a metal; however Steel, Brass and Bronze are alloys.

Q9. Which of the following alloys contains Copper?
निम्नलिखित में से किस मिश्र धातु में कॉपर शामिल होता है?
(a) Brass/ पीतल
(b) Bronze/ कांस्य
(c) German Silver / जर्मन रजत
(d) All the above / उपर्युक्त सभी
Show Answer
Sol. Brass consists 68-71% Copper and rest is Zinc. Bronze consists 88% Copper and 12% Tin. German silver has almost 60% Copper.

Q10. Pencil lead is:
पेंसिल लेड है:
(a) Graphite/ ग्रेफाइट
(b) Charcoal/ चारकोल
(c) Lamp black/ लैंप काला
(d) Coal/ कोयला
Show Answer
Sol. Graphite and Diamond both are allotropes of Carbon. Pencil cores are made of Graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.

Q11. What is heavy water?
भारी पानी क्या है? 
(a) Oxygen + Heavy Hydrogen / ऑक्सीजन + हैवी हाइड्रोजन
(b) Hydrogen only / केवल हाइड्रोजन
(c) Hydrogen + New Oxygen / हाइड्रोजन + न्यू ऑक्सीजन
(d) Heavy Hydrogen + Heavy Oxygen / हैवी हाइड्रोजन + हैवी ऑक्सीजन
Show Answer
Sol. Heavy water (D2O) is also called deuterium oxide, water composed of deuterium, the hydrogen isotope with a mass doubles that of ordinary hydrogen, and oxygen. Deuterium, (D, or 2H), also called heavy hydrogen

Q12. Which is used as Laughing gas is–
हास्य गैस (लाफिंग गैस) के रूप में उपयोग की जाने वाली गैस है- 
(a) Nitrous Oxide / नाईट्रस ऑक्साइड
(b) Nitrogen dioxide / नाइट्रोजन डाइऑक्साइड
(c) Nitrogen Trioxide / नाइट्रोजन ट्रायऑक्साइड
(d) Nitrogen Tetra Oxide / नाइट्रोजन टेट्राऑक्साइड
Show Answer
Sol. Nitrous Oxide (N₂O) is a also known as laughing gas. It is a colourless gas with a sweet odour and taste. Inhalation leads to disorientation, euphoria, numbness, loss of coordination, dizziness and ultimately a loss of consciousness. It is also used as the anesthetic gas.

Q13. Which one of the following is also called Stranger Gas?
निम्नलिखित में से किसे अजनबी गैस भी कहा जाता है? 
(a) Argon / आर्गन
(b) Neon / नीओन
(c) Xenon / क्सीनन
(d) Nitrous Oxide / नाइट्रस ऑक्साइड
Show Answer
Sol. Xenon is a chemical gas with symbol Xe and atomic number 54. It is a rare, odourless, colourless, tasteless, chemically unreactive gas. Xenon gas is also known as stranger gas as its volume is low in the atmosphere (0.08 parts per million of xenon). It was discovered in England by the Scottish chemist Willian Ramsay and British chemist Morris Travers in 1898.

Q14. Baking soda is–
बेकिंग सोडा है-
(a) Sodium Chloride / सोडियम क्लोराइड
(b) Sodium Bicarbonate / सोडियम बाइकार्बोनेट
(c) Sodium Hydroxide / सोडियम हाइड्रोक्साइड
(d) None of the above/ उपरोक्त में से कोई नहीं.
Show Answer
Sol. Sodium bicarbonate is also known as Baking Soda. The chemical formula of Sodium Bicarbonate is NaHCO₃.

Q15. The chemical formula of washing soda is
वॉशिंग सोडा का रासायनिक सूत्र है
(a) NaOH
(b) Na₂CO₃
(c) NaHCO₃
(d) Ca(OH)₂
Show Answer
Sol. Sodium Carbonate is known as washing soda. It is used as detergent. Its formula is Na₂CO₃.



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