Question

For the questions 1 3 of Exp. 2, b What is the color of Phenolphthalein, an indicator, in basic condition? (2pt) 1. Clur ren useon Complete and balance the following chemical equations. Show your answer whether it is the precipitation (color) or gas 2. (bubble) evolution reaction if possible. (6pts) H:SO4+ 2NaOH H2O+ Na SO 2 NaHCO+H2SO. Na2SO4+ 2 H2O+CO: PbCl2 NaNO Pb(NOs):+NaCl In Exp. 2, you mixed nine kinds of known solutions with un known aqueous solution in order to identify what un known aqueous solution is. This kind of analysis for the identification of solution in water chemistry is called 3 Mous o6 Coffe Analysis. (2pt) Qalaae Moler Miss 0 For question 4-5 of Exp. 4, Calculate the followings. (6pts) 4. a) The empirical formula for a compound, copper sulfide Cu,S, Meempound 0.4907 g O.0S19C meoper 0.3923 g (A- 63.55 g/mol) Mess one Sy mef 0.0984 g (A.- 32.06 g/mol) O.3M8 3.56 91M0) 32.00 91MP O.O981 CaLor O.00819 b) The % composition of copper in the compound. Xlooo O.B923 Balance the following chemical equations. (4pts) 5 S Cu (0)+ 25(0) CusS (s)+20:() ZCyO (s) + So,(g)

Answer 1

The colos of phenolphthalein an indicator n basic condition i Pink a) th504 NaoH y batandj 20Nazsay +3 NaoH +H20 tc0 Na04 Na Hco3 +Hs04 balanding y Hags04 t2H0+2002 (as bubbele) NaHcoHs04 PhuNaNo PhCNO +Nac balanu Pbckt Na No (Ppt) 2 Nacl Pb (N 3) This king analyss for iduntifrcatron called sohution 1n Nater themiy Is - Anotyois Lualitative

4. a) GivEn rempaund C-1 mcper=-3933An 3-55 g/mel) 0-39231 (AN 0-410 Aw-3-55 g/me = 32-06 3/l) ০-০৭3५ Msulur 2 (u) C-006I 0-39239 X E3.559/me C.00306 C.O0306 1 11 32.66 O0306 Empirical formula = mass XI00 Percantye compesctive - total mass Cups Mass 2X63-ST32.06 (63.552D /composition (u Isq.1 79.8S.