Chemistry Questions for Railway & SSC CGL Exam 2018

Metals Questions

Dear Students,

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. Which of the following is the electron configuration of Calcium? 
निम्नलिखित में से क्या कैल्शियम का इलेक्ट्रॉन विन्यास है?
(a) 2, 8
(b) 2, 8, 7
(c) 2, 8, 8
(d) 2, 8, 8, 2

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Ans.(d)
Sol. Calcium is a dull, grey, solid element with a silver appearance which exists in the solid state. It has a high melting point (1115k) and boiling point (1757K). All these features make it related to the metals. The valence electron configuration of Calcium is 2, 8, 8, 2. Hence, it has a tendency to lose two electrons to get a noble gas configuration. Since it can lose electrons, it can be used in ionic bonding and can form ionic compounds. Like other metals, Calcium also reacts vigorously with dilute acids like hydrochloric acid and produce large amounts of heat, forms Calcium Chloride (CaCl2) and Hydrogen gas. All these properties of Calcium prove that it is a metal.

Q2. Which is the most reactive metal? 
सबसे प्रतिक्रियाशील धातु कौन सी है?
(a) Sodium / सोडियम
(b) Calcium / कैल्शियम
(c) Iron / लोहा
(d) Potassium  / पोटैशियम

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Ans.(d)
Sol. Potassium is the most reactive metal. 
Reactivity series (or Electrochemical Series) of metals- 
Potassium K Most reactive 
Sodium Na
Barium Ba 
Calcium Ca
Magnesium Mg 
Aluminium Al
Zinc Zn 
Iron        Fe 
Nickel Ni
Tin        Sn
Lead Pb
Hydrogen H
Copper Cu
Mercury Hg
Silver Ag
Platinum Pt
Gold Au 
From the above reactivity series, we can see that Potassium is the most reactive metal.

Q3. Which one of the following pairs of metals constitutes the lightest metal and the heaviest metal, respectively? 
धातुओं के निम्नलिखित युग्म में से किसमें क्रमशः हल्की धातु और सबसे भारी धातु है?
(a) Lithium and Mercury / लिथियम और पारा
(b) Lithium and Osmium / लिथियम और ओसमियम
(c) Aluminium and Osmium / लिथियम और ओसमियम
(d) Aluminium and Mercury / एल्यूमिनियम और पारा

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Ans.(b)
Sol. The prescribed options of metals in atomic weight and density are as follows-
    Metals      Atomic No. Atomic Weight (amu) Density
1. Lithium      3 6.941 0.534
2. Mercury      80 200.59 13.534 
3. Osmium      76 190.23 22.61
4. Aluminium      13 26.982 2.70
From this above- mentioned data, it is clear that Lithium is the lightest and Osmium is the heaviest metal. Osmium is the denest naturally occurring element. Therefore, it is the heaviest metal.

Q4. Which is the hardest in the following? 
निम्नलिखित में से क्या सबसे कठोर है?
(a) Diamond / हीरा
(b) Glass / कांच
(c) Quartz  / क्वार्ट्ज
(d) Platinum / प्लैटिनम

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Ans.(a)
Sol. Diamond is the hardest, least compressible and best thermal conductor among all natural materials.

Q5. 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) Platinum/प्लैटिनम
(d) Tungsten /टंगस्टन

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Ans.(c)
Sol. Among non-metals, diamond is the hardest whereas, among the metals, Platinum is the hardest.

Q6. Which one of the following materials is very hard and very ductile? 
निम्न में से कौन सा सामग्री बहुत कठोर है और बहुत नमनीय है?
(a) Carborundum / कॅरबॉरंडम
(b) Tungsten / टंगस्टन
(c) Cast iron / ढलवाँ लोहा
(d) Nichrome / निक्रोम

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Ans.(d)
Sol. Nichrome (NiCr, nickel-chrome, chrome-nickel, etc.) generally refers to any alloy of Nickel, Chromium and often iron and or other elements or substances. Nichrome is very ductile material. It has high specific resistively and minimum temperature coefficient. It also has the ability to operate at high temperature. Nichrome alloys are typically used in resistance wire. They are also used in some dental restorations (fillings) and in other applications.

Q7. The heaviest natural element is? 
सबसे भारी प्राकृतिक तत्व कौन सा है?
(a) Uranium / यूरेनियम
(b) Mercury / पारा
(c) Gold / सोना
(d) Calcium / कैल्शियम

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Ans.(a)
Sol. Uranium is the heaviest naturally occurring element with an atomic no. of 92. It is a pure form of silver-coloured heavy metal. Its most common isotope Uranium-238 has a nucleus containing 92 protons and 146 neutrons. It has a density of 18.95 g/cm3.

Q8. Heaviest metal of the following is made of- 
निम्नलिखित में से सबसे भारी धातु किससे बनी है-
(a) Copper / कॉपर
(b) Uranium / यूरेनियम
(c) Aluminium / एल्युमीनियम
(d) Silver / चांदी

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Ans.(b)
Sol. Uranium is the heaviest naturally occurring element with an atomic no. of 92. It is a pure form of silver-coloured heavy metal. Its most common isotope Uranium-238 has a nucleus containing 92 protons and 146 neutrons. It has a density of 18.95 g/cm3.

Q9. The costliest metal of the world discovered is:
खोजी गई दुनिया की सबसे महंगा धातु कौन सी है
(a) Endohedral Fullerene / एंडोहेड्रल फुलेरिन
(b) Califormium 252 / कैलिफ़ोर्नियम 252
(c) Tritium / ट्रिटियम
(d) Rhodium / रोडियाम

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Ans. (a)
Sol. The material, there discovery and cost per gram in US$ are given below- 
Material Discovery Cost per gram 
(in year) (in US $)
Tritium 1934 30,000
Rhodium 1803 58
Californium-252 1950 27 million 
Endohedral 1985 167 million 
Fullerene 
From the above list, it is clear that Endohedral Fullerene is the costliest material of the world discovered recently. But as the question asked about the costliest metal, it is not a correct answer. However, there are two types of Endohedral Fullerense namely-Endohedral Metallofullerenes and non-metal doped fullerene. Cali-fornium-252 is the costliest metal but is not discovered recently. So the question seems to be incorrect.

Q10. The chemical structure of the pearl is- 
मोती की रासायनिक संरचना क्या है-
(a) Calcium Carbonate / कैल्शियम कार्बोनेट
(b) Calcium Carbonate & Magnesium Carbonate / कैल्शियम कार्बोनेट और मैग्नीशियम कार्बोनेट
(c) Calcium Chloride / कैल्शियम क्लोराइड
(d) Calcium Sulphate / कैल्शियम सल्फेट

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Ans.(a)
Sol. The chemical composition of pearl is 85% Calcium Carbonate, 10-14% Conchiolin and 2-4% of water (CaCO3 and H2O). Conchiolin is a protein.

Q11. The main constituents of pearl are- 
मोती के मुख्य घटक हैं
(a) Calcium Carbonate and Magnesium Carbonate / कैल्शियम कार्बोनेट और मैग्नीशियम कार्बोनेट
(b) Magnesium oxide and Sodium Chloride/ अरगोनाइट और कोन्चिओलिन
(c) Ammonium sulphate and Sodium Carbonate / अमोनियम सल्फेट और सोडियम कार्बोनेट
(d) Calcium oxide and Ammonium Chloride / कैल्शियम ऑक्साइड और अमोनियम क्लोराइड

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Ans.(b)
Sol. The chemical composition of pearl is 85% Calcium Carbonate, 10-14% Conchiolin and 2-4% of water (CaCO3 and H2O). Conchiolin is a protein.

Q12   Name the property of metal in which it can be drawn into thin wires 
धातु के गुण का नाम बताइये जिसके द्वारा इसे पतली तार के रूप में खींचा जा सकता है?
(a) Sonorous/ ध्वन्यात्मक
(b) Ductility/ लचीलापन
(c) Malleability/ आघातवर्धनीयता
(d) Conductivity/ प्रवाहकत्त्व

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Ans.(b)
Sol. Ductility is the property of a metal by virtue of which it can be drawn into wires.

Q13. What are Rubies and Sapphire chemical known as? 
रूबी और सैफायर रसायन को किस रूप जाना जाता हैं?
(a) Silicon Dioxide / सिलिकॉन डाइऑक्साइड
(b) Aluminum Oxide / एल्यूमीनियम ऑक्साइड
(c) Lead Tetroxide / लेड टेट्रोक्साइड
(d) Boron Nitride / बोरन नाइट्राइड 

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Ans.(b)
Sol. Aluminium Oxide is a chemical compound of Aluminium and Oxygen with the chemical formula Al_2 O_3. Corundum is the most common naturally occurring crystalline form of Aluminium Oxide. Rubies and Sapphires are gem-quality in forms of Corundum which owe their characteristic colours to trace impurities.

Q14. Assertion (A) : Sodium metal is stored under kerosene. / अभिकथन(A):सोडियम धातु को केरोसिन में संग्रहीत किया जाता है
Reason (R) : Metallic sodium melts when exposed to air. कारण(R): : हवा के संपर्क में आने पर धातु सोडियम पिघल जाता है
(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).  / दोनों (A) और (R) सत्य हैं, और (R) (A) की सही व्याख्या है.
(b) Both (A) and (R) are true, but (R) is not a correct explanation of (A). / दोनों (A) और (R) सत्य हैं, और (R) (A) की सही व्याख्यानहीं  है.
(c) (A) is true, but (R) is false. /(A) सत्य है , लेकिन (R) असत्य हैं
(d) (A) is false, but (R) is true. /(A) असत्य है , लेकिन (R) सत्य हैं

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Ans.(c)
Sol. Sodium is kept in kerosene to prevent it from coming in contact with Oxygen and moisture present in the air. If this happens, it will react with the moisture and form Sodium hydroxide. This is a strongly exothermic reaction and a lot of heat is generated. Thus, Sodium is kept under kerosene.

Q15. These days yellow lamps are frequently used as street light. Which one of the following us used in these lamps:
इन दिनों पीले लैंप अक्सर सड़क के प्रकाश के रूप में उपयोग किया जाता है इनमें से कौन सा इन दीपक में इस्तेमाल किया जाता है?
(a) Sodium(सोडियम)
(b)Neon(नियॉन)
(c)Hydrogen(हाइड्रोजन)
(d) Nitrogen(नाइट्रोजन)

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Ans.(a)
Sol. There are 2 types of street light bulbs are used by municipalities. They are sodium vapor and mercury vapor bulbs. The mercury vapor bulbs are usually a white ambient light and sodium an orange/yellow light. Compared to LPS (Low-pressure sodium) lamps, high-pressure sodium lamps tend to have a longer life, less lumen per watt efficiency and most importantly a higher colour rendering index.

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- https://www.sscadda.com/2018/05/chemistry-metals-questions-for-railway-ssc-cgl.html