Chemistry Practice: Atomic Masses, Balancing Equations, Identifying Compounds - Prof. W. M, Study notes of Chemistry

Download Chemistry Practice: Atomic Masses, Balancing Equations, Identifying Compounds - Prof. W. M and more Study notes Chemistry in PDF only on Docsity! chrl eKr 3/ protons . fL n"rtron, tY *"rrnumber 3*L etectrons 1328a2+ (6 oro,on, f6 n ut on, ))2 r.r, number electrons /ooDs H1 (,H) : 73,(b"i Lho'{" \ Practice Questions - Chapters 1 thru 3 1) Give the number of protons, neutrons, electrons, and mass number for the following: ' 2) The density of mercury, the only metal to exist as a liquid at room temperature, is 13.6 g/cmt. a) What is the volume of 1.00 kg of mercury in liters? ' 6a,& vn &&A 1.00 liter? 3,6 l\ c' ' . , { ) c) What is the mass of one mercury atom? . , \ (Loo.s't 't Hi\( {l":jg\-i1 -\ = 3nz t ,+t , / \ 6,oLLYl o" ' " tr-ow s ) 3) How many atoms are in 36.5 gm of Sn (atomic weight = 118.7 g/mol) cw\ 4) a) Rutherford etermined the mass of an electron by observing the scatter of alpha particles from thin gold foil. b) Millikan applied electric field to an oil mist where the oil droplets were electrically charged with a radioactive source. What two forces were balanced in this experiment in which the mass of the electron was determined? fr-a, ,l-q ".-*- Q lee l-r- t Lk u h., o J-\ J \ l W.i " ) i-L r '_ I I Y )D g tTq z\ - t^h*\) z3 l / g3:x /b cn hrYt s ,,.Fo(lD cWt 5) A Compound known as fluoroacetal is composed of 20.71.% C,13.79 Yo O, and 65.50% F. What is its empirical formula? otw\ Cl*p\ What is its chemicalformula? t ra,44 u*Lh: 4C- {tl 2^{ o 1W2-o | - Ll t '6 f ga/ ' r l - , f o5a P*-l4,ol s "l$' oz- f \ tcv Hr N,ol* y i= tQ. [ ' z -2- 9 1 - t l c/'*nr. (o-,n. = Lg H, u Nly 0- / 6 'a l '= / 6 "oo q1,l l 7) Balance the following three chemical reactions. Avoid fractional coefficients in your final answers. , . U f t l / 6la(a 7 r trn, lgy * 5 o,El ) ?*otut * 5u,o(t) b) I tzos(s) *-. f .o1rl>Lt,( i+ {coz(e) c) Gaseous oxygen reacts with gaseous ammonia, NH3, to give gaseous nitrogen dioxide and tiquid ihydrogen ^o o*id". o ' rtN 4 a lN 0z 4 l{-o 1 ot r 4 tr{a - ,l AIOL +( l1;o 8) 10.0 g of iron metal is reacted with excess chlorine to give lron (ll l) Chloride according to the reaction cl*V Ta) 2Fe(s)+ 3 Cl2(g) 2 FeClg (s) . How many grams of Clz is consumed when all 10.0 g Fe rgacts? ^ A \ t o ox-(gtrfr) (# l ( ffiW)' / q os lf only 18.5 g FeClg is obtained after reacting 10.0 e Fe, what is the percent yield?b) ('tFdLl#A trr Wffi::i = 21o43F % Y U,'LQ' tq.t# (l*rf) 21 o43fr+ s 6317u o\nq L7l 12.5 g Zn metal is added to 250. mL of 1.000 M HCI solution and allowed to react to form aqueous solution of ZnClz(aq) and H2 gas. a) Write a balanced equation for this reaction. Z n +- L[k-4* a 7^ U.- +- t{>- b) Calculate the limiting reactant in this reaction? /x'rs z" (&J/l9t s o,/qt ,rL&> \ 6sl 313rn1l t *n / [u,rrur-,4"4 (ffi*-tS(#) s o.tL{ m^<-t{> . o, lk_p_ts LfL 6 ( ) 1/ c) What is the maximum amount of Hz gas in moles that can form? 6,1>Strn "L tl- t S tn a-{ c,*r# l4^+ '*" &'vt\) d) Determine how much excess reactant remains in units of moles. a l Q)-ce-t< re-k fu4/+ /S Z-n g"t1J 7n tnh,-\?n - ?r, .n^ulnL /:-t ?-zt - $,nJ *rt € 1'33 >Lyco-M /n *,4 c\n^P3 19) Draw Lewis structures for the following compounds and indicate the formal charges r ^1 of each atom in the molecule. Indicate resonance if present.I , n \ ' \^frY Jw " I 13' Noz crF3 e- pair Eeometryt +e,-hr>L{'1*{*[ e- pair u"o^"r, Lr,&**t p bna { . l / 1 A molecular geometry, k {rrrlnnaLw\ moleculargeometry (t r,** . . . t ? t o * l a I tT .'-T: f 'lJ L - - t l a . ( . ' o r o ? o , "O =N-o 1 t 4 . 8/r "Yoo:O-N-h a e - w / t 8 t l t n 1 . 1 a 1l=^(A-F i I o ' ite : , 4 SFq :F I . 1 + . . . O'E -? -F ^ e / - - J I ' c - t L € ) I l e l - ' a . 6 \ What is the electronic and molecular geometries of each? Indicate if molecule is polar or nonpolar. 13- NOz ln q l-o qun,{ 6 r'6"fnn,l"'t p fa nat SFa {nt a 4 r-(';,I";:;,,dil clF3 I I I ncar b"wt lo-sLry- So-e-Sa-k) 20) Indicate the formal charges of the following Lewis structures. cL^f3. ")(t G a , H*N=O b) t \ f t 'o) { t - l } l - t i' / . { ' L . - r H-O=N a t .l-v^t o onoP L tly*^",XJ abr-f .l 1"**\ fnvtQ,c- ^ -) 3 *'*'ti Which is more favorable structure (a or b) based on formal charges and why? n S Lr".{E U*y& ( *\ rrl or(--z Q-*r.'&{L- a4/'& k [ta'n1' Q.r.,n^k rni*t-r LIe"4 *'h*"q*- \Ya*'r"n&*'r)'