611. Element stored in wax: Lithium 612. Sodium and potassium are kept in:Kerosene  613. Rubber is soluble in: Benzene (C6H6) 614. The only acid shows the characteristics

576. The gas emitted by burning wood is mainly: Carbon dioxide  577. Containers for carrying strong acids are made of:  Lead 578. The process of

541. What is the commercial name of calcium nitrate?  Norwegian saltpetre  542. Which are the important phosphatic fertilisers?  Calcium superphosphate, nitro phosphate & triple phosphate 

506. What causes the foul smell of the rancid butter? Butyric acid  507. Which compound of silver is used in the silvering of mirrors?  Silver

471. The geosynchronous satellites orbit——- km above the earth?  36,000 km  472. Which substance has the highest expansivity in normal temperature? Caesium  473. What is

436. Which metal is used in the fireworks to give them a purple colour?  Rubidium 437. Which is the least electronegative & the most electropositive

411. Amyl acetate has the smell of: (a) Grapes (b) Orange (c) Pineapple (d) Banana Answer: (d) 412. Which one of the following is not

381. The acid in soft drinks: (a) Acetic acid (b) Carbolic acid (c) Citric acid (d) Carbonic acid Answer: (d) 382. The acid present in

351. The isotope used for the treatment of Cancer: (a) Carbon-14 (b) Uranium-238 (c) Cobalt-60 (d) None of these Answer: (c) 352. The chemical property

321. Wax is soluble in: (a) Benzene (b) Water (c) Alcohol (d) Iodine Answer: (a) 322. The acid contained in onion: (a) Oxalic acid (b)

291. If the pH value of a substance is below 7, it is: (a) Acid (b) Base (c) Neutral (d) Water Answer: (a) 292. The

261. 15th group is called ……. group: (a) Carbon                                 

226. Gunmetal is made from-  tin and copper. 227. Cobalt is used in making-  rust-resistant alloys. 228. Steel is a form of iron. To make

191. Butane is used in- cigarette lights. 192. A mixture of oxygen and acetylene gases are used for-  gas welding. 193. Methane is the main

161. The permanent hardness of water can be removed by adding — Answer: Washing Soda 162. The alcohol used in power alcohol is Answer: ethyl

126. The gas usually filled in an electric bulb is — Answer: Nitrogen 127. Sodium burns in air to give- Answer: Sodium peroxide 128. Which

91. Which of the following is the lightest metal? Answer: Lithium 92.  Carborundum is — Answer: Silicon Carbide 93. Carbon, diamond and graphite are together

61. Sir Humphry Davy discovered: (a) Helium    (b) Hydrogen (c) Sodium  (d) Oxygen Answer: (c) 62. A natural fertilizer: (a) Urea       

31. The element used for radiographic imaging: (a)Calcium        (b) Strontium       (c) Barium          (d) Beryllium Answer: (c)

1. The gas formed when Potassium permanganate is heated: (a) Nitrogen (b) Oxygen (c) Hydrogen (d) Ammonia Answer: ( b) 2. The pungent smell emitted

Discovery of Elements – Inert Gases Element Discoverer Argon Sir William Ramsay and Lord Rayleigh Neon Sir William Ramsay and M.W. Tavers Krypton Sir William

कार्बन को जलने के लिए पर्याप्त ऑक्सीजन न होने से क्या बनता है? Ans-कार्बन मोनोऑक्साइड। किस धातू को मिट्टी के तेल में रखा जाता है Ans-सोडियम कार्बन डाइऑक्साइड गैस हवा से भारी होती है या हल्की? Ans-भारी होती है। सर्वाधिक “ कठोर पदार्थ“कौन सा है Ans-हीरा ठोस कार्बन डाइऑक्साइड का प्रयोग कहां होता है? Ans-रेफ्रिजरेशन में। पेट्रोलियम किसका मिश्रण है? Ans-हाइड्रोकार्बन का। खाद्य पदार्थों के संरक्षण में किस अम्ल का प्रयोग किया जाता है Ans-बेन्जाइक अम्ल मेथेन गैस क्या है? Ans-ईंधन। ट्यूबलाइट में कौन सी गैस भरी होती है Ans-मरक्यूरिक ऑक्साइड