Formatting page ...
GOLDCREST HIGH-LATUR ON THE WINGS OF EXCELLENCE CYCLE TEST-05 TIME:1 HOUR DATE:-23/11/2017 SUBJECT:-CHEMISTRY GRADE-10 MARKS:40 (MOLE CONCEPT & STOICHIOMETRY) General Instructions Answers to this paper must be written on the paper provided separately. You will not be allowed to write during the first 15 minutes. This time is to be spent in reading the question paper. The time given at the head of the paper is the time allotted for writing the answers. The intended marks of questions or parts of questions are given in brackets [ ]. Question-01 (a) Define Gay Lussac s Law . 2 C4H10 +13 O2 8CO2 + 10 H2O . 400 c.c. of butane is burnt with 3000 c.c. of oxygen Find (i) the amount of carbon dioxide formed and unused oxygen (ii) If 4 moles of butane is used, than find the number of moles of carbon dioxide formed. (iii) Also find the number of molecules of carbon dioxide present at the same time (iv) If 2 moles of butane is used, find the volume of carbon dioxide formed (Atomic Weight of C=12,O=16,H=1) [5] (b) Define Avogadro s Law relating it with in terms of particles. A flask contains 3.2 g of sulphur dioxide. Calculate (i) the moles of Sulphur dioxide present in the flask. (ii) the number of molecules of sulphur dioxide present in the flask. (iii) the volume occupied by 3.2 g of Sulphur dioxide at S.T.P (S-32 ,O 16). [4] (c) Define Gram Atom, Molar volume. A gas cylinder contains 24 x 10 24 molecules of nitrogen gas .If Avogadro s no is 6 x 1023 and the relative atomic mass of nitrogen is 14,Calculate: (i) Mass of nitrogen gas in the cylinder. (ii) Volume of nitrogen at S.T.P in dm3 [3] (d) Commercial NaOH weighting 30g has some sodium chloride in it. The mixture on dissolving in water and subsequent treatment with excess silver nitrate solution formed a precipitate weighing 14.3g What is the percentage of sodium chloride in the commercial sample of sodium hydroxide? The reaction is : NaCl + AgNO3 AgCl + NaNO3( RMM of NaCl-58, AgCl-143) [2] (e) Define Relative Molecular Mass. A certain gas X occupies a volume of 100 cm 3 at S.T.P and weighs 0.5g .Find its relative molecular mass. [2] (f) The equation for the burning of octane is : 2 C8H18 + 25O2 16 CO2 + 18 H2O. (i) How many moles of carbon dioxide are produced when one mole of octane burns? (ii) What volume, at S.T.P, is occupied by the number of moles determined in (i). (iii) If the relative molecular mass of carbon dioxide is 44,what is the mass of carbon dioxide produced by burning two moles of octane? (iv) What is the empirical formula of octane? [4] (g) What do you mean by Percentage composition? Calculate the % of water of crystallization in FeSO 4.7H2O.(F-56,S32,H-1,O-16). [2] (h) Define Vapour Density. Vapour density of a gas is 8.5.Calculate the following in 8.96 dm3 of gas at S.T.P.(i) Number of moles of gas. (ii) Weight of the gas in grams [3]
|
