Question

18. A student performed the same experiment you did in the lab to find the chemical formula of a copper chloride hydrate with the general formula Cu,Cl,.2H20. Water molecules evaporated when the solid was heated until it turned brown then the sample was dissolved in water to react with a coil of aluminum wire and copper deposited on the coil. The student weight the initial material in a beaker before and after drying, and weight the deposited dried copper powder to obtain the following data table: DATA TABLE 1.100 g Mass of hydrated sample (g) 0.870 g Mass of dehydrated sample (g) 0.230 g Mass of water evolved (g) 0.409 g Mass of copper (g) How many moles of water were in the sample of copper chloride hydrate? a. How many moles of copper were in the sample of copper chloride? b. How many moles of chlorine were in the sample of copper chloride? c. Write the proper chemical formula for the compound that the student tested. d. 19. According to Arrhrenius an acid is: a) a substance that produces OH- ions when dissolved in water. b) a molecule (or ion) that donates a proton (H*). c) a substance that produces H ions when dissolved in water. d) a molecule (or ion) that accepts a proton (H').

Answer 1

0.230g =0,0128 mol 18 @ 'No. of mores of water = ma : Molar mass of water, [Molar mass of water=1800159mol - 18.015 g/mol ® No. of moles of cu = mass of cu Molar mass of Cee. = 0.4099 - 53.549mon = 0.0064 mol, @ mass of chlorine in the sample = Mass of dehydrated sample- mass of ce = (0.870-0.409) g . = 0.4619 No. of moles of chlorine = 4.6 mol = 0.0130 mo @ ele: el! H20 in the sample= 0.00647: 0.0130:0.0128 = 1: 2:03: 2 1! 2:2 1.The chemical formula of the compound es 1 cuch. 2H2O (Ans) 19 According to Archenéis an and is ---@ (a substance that produces Htions when dissolved in water).