(c)<\/strong>
\n<\/p>\n(d)<\/strong><\/p>\n\n- A white precipitate of lead chloride appears which dissolves on heating.<\/li>\n
- A white insoluble precipitate of Barium sulphate is obtained.<\/li>\n
- White crystals of sugar turn to a black spongy mass called sugar charcoal.<\/li>\n
- A brisk effervescence with the release of colourless, odourless, acidic gas that extinguish glowing splint i.e., carbon dioxide gas is evolved.<\/li>\n
- A colourless gas with smell of burning sulphur i.e., Sulphur dioxide is released. A yellow crystal settles at the bottom i.e., sulphur.<\/li>\n<\/ol>\n
(e)<\/strong><\/p>\n\n- Electron affinity<\/li>\n
- Froth Floatation Method (concentration of ore)<\/li>\n
- Nickel<\/li>\n
- Addition reaction<\/li>\n
- Valence electron<\/li>\n<\/ol>\n
(f)<\/strong>
\n
\n
\n(g)<\/strong>
\n
\n(h) (i)<\/strong><\/p>\n\n- Prop-1-ene<\/li>\n
- Butr-2-yne<\/li>\n
- Ethan-1-al<\/li>\n<\/ol>\n
(ii)<\/strong><\/p>\n\n- < (less than)<\/li>\n
- < (less than)<\/li>\n<\/ol>\n
SECTION-II (40 Marks)<\/span>
\n(Attempt any four<\/strong> questions from this section)<\/em><\/p>\nQuestion 2:<\/strong>
\n(a)<\/strong> Use the letters<\/strong> only written in the Periodic Table given below to answer the questions that follow: [4]<\/strong>
\n<\/p>\n\n- State the number of valence electrons<\/strong> in atom J<\/strong>.<\/li>\n
- Which element shown forms ions<\/strong> with a single negative charge?<\/li>\n
- Which metallic element<\/strong> is more reactive than R<\/strong>?<\/li>\n
- Which element has its electrons arranged in four shells<\/strong>?<\/li>\n<\/ol>\n
(b)<\/strong> Fill in the blanks by selecting the correct word from the brackets: [2]<\/strong><\/p>\n\n- If an element has a low ionization energy then it is likely to be …………. (metallic\/non metallic).<\/li>\n
- If an element has seven electrons in its outermost shell then it is likely to have the ……….. (largest\/smallest) atomic size among all the elements in the same period.<\/li>\n<\/ol>\n
(c)<\/strong> The following table shows the electronic configuration of the elements W, X, Y, Z:<\/p>\n\n\n\nElement<\/td>\n | W<\/td>\n | X<\/td>\n | Y<\/td>\n | Z<\/td>\n<\/tr>\n |
\nElectronic configuration<\/td>\n | 2, 8, 1<\/td>\n | 2, 8, 7<\/td>\n | 2, 5<\/td>\n | 1<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Answer the following questions based on the table above:<\/p>\n \n- What type of Bond is formed between: [2]<\/strong>
\n1. W and X \u00a0 \u00a0 \u00a0 \u00a0 \u00a02. Y and Z<\/li>\n- What is the formula of the compound formed between: [2]<\/strong>
\n1. X and Z \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 2. W and X<\/li>\n<\/ol>\nAnswer:<\/strong> \n(a)<\/strong><\/p>\n\n- No. of Valence electrons in atom J = 5<\/li>\n
- Element M<\/li>\n
- Element T is more reactive than R.<\/li>\n
- Element T has its electrons arranged in four shells<\/li>\n<\/ol>\n
(b)<\/strong><\/p>\n\n- Metallic<\/li>\n
- Smallest<\/li>\n<\/ol>\n
(c) (i)<\/strong><\/p>\n\n- Ionic bond.<\/li>\n
- Covalent bond.<\/li>\n<\/ol>\n
(ii)<\/strong> \n<\/p>\nQuestion 3:<\/strong> \n(a)<\/strong> Write a balanced chemical equation<\/strong> for each the following: [3]<\/strong><\/p>\n\n- Burning of ethane in plentiful supply of air.<\/li>\n
- Action of water on Calcium carbide.<\/li>\n
- Heating of Ethanol at 170\u00b0C in the presence of conc. Sulphuric acid.<\/li>\n<\/ol>\n
(b)<\/strong> Give the structural formulae of each of the following: [3]<\/strong><\/p>\n\n- 2-methyl propane<\/li>\n
- Ethanoic acid<\/li>\n
- Butan-2-ol<\/li>\n<\/ol>\n
(c)<\/strong> Equation for the reaction when compound<\/strong> A is bubbled through bromine dissolved in carbon tetrachloride is as follows: [2]<\/strong> \n<\/p>\n\n- Draw the structure of A.<\/li>\n
- State your observation during this reaction.<\/li>\n<\/ol>\n
(d)<\/strong> Fill in the blanks using the appropriate words given below: [2]<\/strong> \n(Sulphur dioxide, Nitrogen dioxide, Nitric oxide, Sulphuric acid)<\/p>\n\n- Cold, dilute nitric acid reacts with copper to give ………..<\/li>\n
- Hot, concentrated nitric acid reacts with sulphur to form ……….<\/li>\n<\/ol>\n
Answer:<\/strong> \n \n(d)<\/strong><\/p>\n\n- Nitric oxide.<\/li>\n
- Sulphuric acid<\/li>\n<\/ol>\n
Question 4:<\/strong> \n(a)<\/strong> Identify the gas evolved<\/strong> and give the chemical test<\/strong> in each of the following case: [2]<\/strong><\/p>\n\n- Dilute hydrochloric acid reacts with sodium sulphite.<\/li>\n
- Dilute hydrochloric acid reacts with iron (II) sulphide.<\/li>\n<\/ol>\n
(b)<\/strong> State your observations when ammonium hydroxide solution is added drop by drop and then in excess to each of the following solutions: [2]<\/strong><\/p>\n\n- copper sulphate solution.<\/li>\n
- zinc sulphate solution.<\/li>\n<\/ol>\n
(c)<\/strong> Write equations for the reactions taking place at the two electrodes<\/strong> (mentioning clearly the name of the electrode) during the electrolysis of: [4]<\/strong><\/p>\n\n- Acidified copper sulphate solution with copper electrodes.<\/li>\n
- Molten lead bromide with inert electrodes.<\/li>\n<\/ol>\n
(d)<\/strong><\/p>\n\n- Name the product formed<\/strong> at the anode<\/strong> during the electrolysis of acidified water using platinum electrodes.<\/li>\n
- Name the metallic ions<\/strong> that should he present in the electrolyte when an article made of copper is to be electroplated with silver. [2]<\/strong><\/li>\n<\/ol>\n
Answer:<\/strong> \n(a)<\/strong><\/p>\n\n- Sulphur-di-oxide gas is evolved.
\nColourless, gas with smell of burning sulphur. It turns acidified potassium dichromate orange to green.<\/li>\n - Hydrogen sulphide gas is evolved.
\nColourless gas with smell of rotten eggs. It turns lead acetate paper black.<\/li>\n<\/ol>\n(b)<\/strong><\/p>\n\n- Bluish white precipitate appears which dissolves in excess of NH4<\/sub>OH and give an inky blue solution of tetra amino copper sulphate.<\/li>\n
- A gelatinous white precipitate appears which dissolves in excess of NH4<\/sub>OH and give a clear transparent colourless solution of tetra amine zinc sulphate.<\/li>\n<\/ol>\n
(c)<\/strong> \n \n(d)<\/strong><\/p>\n\n- Oxygen gas.<\/li>\n
- Silver ions\/Ag+<\/sup>.<\/li>\n<\/ol>\n
Question 5:<\/strong> \n(a)<\/strong> A gas cylinder contains 12 \u00d7 1024<\/sup> molecules of oxygen gas. \nIf Avogadro\u2019s number is 6 \u00d7 1023<\/sup>; Calculate: \n(i)<\/strong> the mass of oxygen present in the cylinder. \n(ii)<\/strong> the volume of oxygen at S.T.P. present in the cylinder. [O = 16] [2]<\/strong> \n(b)<\/strong> A gaseous hydrocarbon contains 82.76% of carbon. Given that its vapour density is 29, find its molecular formula<\/strong>. [C = 12, H = 1] [3]<\/strong> \n(c)<\/strong> The equation 4NH3<\/sub> + 5O2<\/sub>\u00a0 \u00a0\u2192 \u00a0 4NO + 6H2<\/sub>O, represents the catalytic oxidation of ammonia. If 100 cm3<\/sup> of ammonia is used calculate the volume of oxygen required to oxidise the ammonia completely. [3]<\/strong> \n(d)<\/strong> By drawing an electron dot diagram show the formation of Ammonium Ion<\/strong> [AtomicNo. :N =7 and H = 1] [2]<\/strong><\/p>\n |