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Gujarat Research SocIely s JASUDBEN M. L. SCHOOL AND BLOOMINGDALES PRE-PRIMARY 052 Corner of 16th and 17th Roads, Khar, Mumbai 400 .MadhuriShah Campus, Ramakrishna Mission Road, 2023-2024 Preliminary Examination Date: 12/12/23 Std: X Time: 2 hours Subject: Chemistry Marks: 80 separatelv. Answers to this Paper must be written on the paper provided minutes. You will not be allowed to write during first 15 This time is to be spent in reading the question paper: writing the answers. The time given at the headof this Paper is the time allowed for Section A is compulsory. Attempt any four questions from Section B. The intended marks for questions or parts of questions are given in brackets []. This Question paper contains eight printed sides. SECTION A (40 Marks) (Attempt all questions from this Section.) Question 1 [15] Choose the most appropriate option: (i) The electrolysis of acidified water is an example of: a) Reduction b) Oxidation c) Redox reaction d) Synthesis (ii) The gas law which relates the volume of agas to moles of the gas is: a) Boyle'sLaw b) Charles' Law c) Avogadro's Law d) Gay Lussacs Law (i ) Formation of chloroform from methane and chlorine is an example of which reaction? a) Addition b) Dehydration c) Substitution d) Elimination 1 (iv) Which of the following methods is used for the dressing of sulphide nre. a) Hydrolytic method b) Froth floatation c) Leaching d) Calcination (v) Duralumin is an alloy of: a) Copper and tin b) Copper and zinc c) Aluminium and Copper d) Aluminium and tin (vi) The element having smallest size in the periodic table: a) He b) H c) F d) Ne (Vi) The correct arrangement of metals in the decreasing order of reactivity is: a) Al > Zn > Fe > Cu b) Cu > Fe> Zn > Al c) Cu > Zn > Fe> Al d) Al > Fe > Zn > Cu (vii) The element having lowest ionization potential in period 3 is: a) Sulphur b) Magnesium c) Aluminium d)Sodium (iX) How many grams of Naare present in 0.2 moles of it? a) 23 g b) 4.6 g c) 46 g d) 2.3 g (x) Which is the alloy used for welding: a) Bronze b)Steel c) Brass d) Solder (xi) Astrong electrolyte from the following is: a) Acetic acid b)Oxalic acid c) Ammonium hydroxide d) Sodium hydroxide 2 X Which of the followg eactons gvesOpper asa iodtic alPasing d ammonia over heated coppe oxo bAdding diute bydrhlonc acd to roprer oxIde Heating copper ox de d) Dassng oXygen Over heated cooper oxIde XI The incorect statement about acid is al the gve iO on water b) they are sOur in taste c)they tum blue Iitmus red phenolphthalein d theygve pink colour with to sulphur it gets oxidized to XIV Wher hot concentrated sulphuric acid is added (d) None of these (c) H;sO. (b) SO al ;S of ammoniais carTied out XV The temperature at which catalyticoxidation (d) 800 C (c) 1000 C (b) 450C a 200 C Question 2 preparation of hydrogen The diagram shows an apparatus for the laboratory [5] chionde liy hogen chlonde B a identfy Aand B b)Write the equation for the reaction occuring in the flask. C) What is the nethod of collection of hydrogen chlonde gas? density of hydrogen d) What does the method of collection tell you about the tdonde? at is the dry ng agent used here? [5] (O= 16). oxygen. of molecule mass of one the Calculate (i) a) soda. Crystallisation in washing of water b)Calculate the O= 16, H= 1). (Na = 23, C=12, the water as shown by and dioxide oxidisesethyne tocarbon c) Oxygen equation: 2C,H, + 50, What volume 4CO, + 2H,0 produce 8.4 dm3 of carbon to required is of ethyne gas at STP dioxide at STP? [H =1, C= 12,O= 16] brackets: the instruction given in the per as following the Arrange (ii) [5) electronegativity] (a) Li, F, O, N [increasing order of potential] (b) Na, S, AI, CI [increasing order of lonization covalent bonds] (c) O2, N2, Cl2 [increasing order of number of cathodel (d) Zn , Na', Cu?, Ag [order of preference of discharge at the (e) Br, F. CI, I[Decreasing order of atomic radius] (iv) Give one word or aphrase for the following statements: (a)The tendency of an element to form chains of identical atoms. [5] (b)The chemical bond formed by a shared pair of electrons, each bonding atom contributing one electron to the pair. (c) Electrode used as cathode in electrorefining of impure copper. (d) The tendency of an atom to attract electrons to itself when combined in a compound. (e) The energy released when an electron is added toa neutral gaseous isolated atom to form a negatively charged ion. -o - I name for the following: (v) (a) GiveIthe IUPAC H 1) H O H-C-C-C-H H H 4 [2] 2) H H HC -C C H H-C- H (b) Draw the structure for each of the following compounds: (3) 1) But-1-ene 2) Propanoic acid 3) Ethanol SECTION II(40Marks) Section.) (Attempt any four questions from this Question 3 compounds. Also state the formation of the foliowing show to diagrams dot Draw (i) formed: [2] the type of bond a)Ammonia (2] b) Sodium chloride of an organic formula and the molecular formula empirical the Determine hydrogen. Its (i) is 26.24% Oxygen and 4.92% compound whose composition by mass vapour density = 61. [3] [H=1, C= 12, O=16] (i i)Namne the gas produced: witha metal sulphide. a) on reaction of dilute sulphuric acid to sodium sulphite. b) when dilute sulphuric acid is added electrolysis of acidified water. c) at the anode during the [3) Question 4 present in 0.25 moles of hydrogen gas () How many molecules and atoms are [2] CsH10 and also give their names. ( )Give the all the possible isomers of [3) (u) Name the following: a)Alkali metal present in fourth period (b)Halogen present in second period c) Inert gaspresent in third period. 5 (iv)Give balanced chemical equation for the following reactions a) Calcium carbide to ethyne b) Ethyl acetate from acetic acid c) Ethanol from ethyl bromide. (3) Question 5 () The following table represent the elements and the atomic numbe: Element Atomic Number 13 7 R 10 With reference to this, answer the following using only the alphabets given in the table: (a) Which element combines with hydrogen to form a basic gas? (b) Name the element, which forms an ionic compound with chloine. (c) Write the formula for the above compound formed in (b). () ldentity the substance in each of the following. (a) The electrode that increases in mass silver. |3) during the electroplat1ng of (b) The acid that is a dehydrating as wellas a drying agent. (c) The catalyst used to OxIdize ammonia into nitric oxide (i)Give a balanced chemical equation for each of the following. (a) Action of dilute hydrochloric acid on magnesium bicarbonate (b) Laboratory preparationof ammonia from ammonium chloride. (c) Reaction of excess ammoniawith chlorine. (d) Reaction of copper with concentrated sulphuric acd (4) Question 6 (i) Give reason. (a) Noble gases have zero electron affinity values. (b) Which is larger Na or CI ?Why? () Give the reactions occurring and the observations during the eloctrolysis of copper sulphate solution using copper electrodes: (a) at the anode (tb) at the cathode (21 (21 w) Give abalanced chemical equation for each of the following 14) (a) Action of conc Nitic acid on Sulphur (b)Laboralory preparat1on of Nitric acid (c) Reaction of Zinc sulphide and dilute sulphuric acid. (d) The action of conc. Sulphuric acid on Carbon Question 7 (0) An element has an atomic number 16. State. [2] (a) The period to which it belongs (b)The number of valence electrons. (2] () How will you distinguish between: (a) dilute hydro chloric acid and dilule sulphuric acid using lead nitrate solution. (b) Sulphur dioxide and carbon dioxide using potassium permanganate solution. (i)Given below is amethod to show the extraction of Aluminium [3) (a) Name the process used for the purification of the ore used in the extraction. (b)Why is cryolite added during electrolytic reduction of fused alumina? (c) Why is powdered coke sprinkled on top of the electrolyte? (iv) State one relevant observation for each of the folowing: (a) Atthe cathode,when aqueous copper (l) sulphate is electrolyzed using platinum electrode. (b) Burningof ammonia in oxygen. (c) Action of concentrated Sulphuricacid on glucose. (3] Question 8 () Fllup the blanks with the correct choice given in brackets conduct (a) The polar covalent compound in gaseous state that does not .(carbon tetra chloride, ammonia, methane) electricity is (2) (b) The compound that does not have a lone pair of electrons is (water, ammonia, carbon tetra chloride) [2] (ii) Name the following: (a) Second member of the homologous series of alkenes. (b) Fourth member of the alcohol series. [3] (ii)Copy and complete the table given below: Lab Preparation of Reactants Used Drying Agent Used Method of Collection Ammonia (iv) Copy the following table and write the colour of the precipitate in (i) to (i) and the nature of the precipitate (soluble or insoluble) in (iv) to (vi). Aqueous salt solution Colour of precipitate when NaOH is added in a small quantity Copper (0) sulphate () (i) (i) Lead nitrate Calcium chloride r k********: [3j Nature of precipitate (soluble or insoluble) when NaOH is added in excesS (iv) (v) (vi)
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