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Title: An unknown hydrate of cobalt(II) cyanide, Co(CN)2 • XH2O, is heated to give 32.7 Post by: OldSpice on Dec 8, 2014 An unknown hydrate of cobalt(II) cyanide, Co(CN)2 • XH2O, is heated to give 32.7% water. What is the water of crystallization (X) for the hydrate?
A) 2 B) 3 C) 4 D) 6 E) 10 Title: Re: An unknown hydrate of cobalt(II) cyanide, Co(CN)2 • XH2O, is heated to give 32.7 Post by: Electric on Dec 11, 2014 Content hidden
Title: Re: An unknown hydrate of cobalt(II) cyanide, Co(CN)2 • XH2O, is heated to give 32.7 Post by: OldSpice on Dec 14, 2014 Perfect!
..Thank you so much for your support Title: Re: An unknown hydrate of cobalt(II) cyanide, Co(CN)2 • XH2O, is heated to give 32.7 Post by: Electric on Dec 14, 2014 My pleasure
Title: Re: An unknown hydrate of cobalt(II) cyanide, Co(CN)2 • XH2O, is heated to give 32.7 Post by: smi3 on May 9, 2022 The game plan with these is to figure out the number of moles of H2O there are per mole of CaSO4. Start by assuming any quantity of CaSO4 X H2O.
Assume 100.0 g of CaSO4 XH2O. 20.9 % of that = 20.9 g That is the mass of water. 1 mole of water = 18.0 g 20.9 g x 1 mol/18.0 g = 1.16 mol H2O 100 % - 20.9 % = 79.1 % CaSO4 79.1 g is the mass of CaSO4 1 mole of CaSO4 = 40.1 + 32.1 + 4(16.0) = 136.2 g 79.1 g x 1 mol / 136.2 g = 0.581 mol CaSO4 Now calculate the ratio of mol H2O to mol CaSO4 1.16 / 0.581 = 2.00 So X = 2 |