Question

8. Balanced chemical equation for the formation of copper sulfide from copper and sulfur QUESTIONS 1. Can you determine the molecular formula of a substance from its percent composition? 2. Given that zinc chloride has a formula weight of 136.28 amu, what is its formula? 3. Can you determine the atomic weights of zine or copper by the methods used in this experiment? If so, how? What additional information is necessary to do this? 4. How many grams of zinc chloride could be formed from the reaction of 3.57 g of zine with excess HC1? 5. Aluminum sulfide reacts with water to form aluminum hydroxide and hydrogen sulfide. (a) Writea balanced equation for this reaction. (b) How many grams of aluminum hydroxide can be obtained from 10.5g of aluminum sulfide?

Answer 1

No-8 Balance chemical equation for formation of copper sulfide from copper and sulfur 2 cu + s rightarrow cu_2 s = 2 cu^+ + s^2 minus Answer No 1 The present composition can provide only the empirical formula. For finding out molecular formula, molecular mass must be given. Either molecular mass can be find out by doing experiment. Let say example = A unknown compound contains 85-63% C and H 14.37 %. Experimental molar mass is given S6 g/mole. Solution assume we have 10 gmy comp then we has 85.63 g y c and 14, b 7gg Now mole of C = wt/mw = 85.63/12 = 7.13 molw g C mole of H = 14.27/4.008 = 14.26 mole. So for empirical formula = we need only molar composition = so mole of C/mole of H = 7.13/14.26 = 1/2 so empirical formula is CH_2.