1 (UAN (UAN 2005 2005//2006 2006)) H2O(l) → H(g) + ½ O2(g) ; ΔH = + 68,3 kkal H(g) + ½ O2(g) → H2O(g) H2O(g) ; ΔH = - 57,8 kkal H2O(l) → H2O(s) ; ΔH = - 1,4 kkal !"#$a%a& !&'al *a" !s !&a* #a a*ala% A -11,. kkal +11,. kkal -.1,0 kkal +.1,0 kkal +12,47 kkal Pembahasan : Konsep reaksi bersusun !aks !"#$a%a& !s !&a* #a a*ala% H2O(s) → H2O(g) l!% ka"!&a '# s#s#&la% s!*!ka& 'ga !"saaa& a&g *k!'a%# aga" !&g%aslka& "!aks a&g *&g&ka& 'a !&g&g&ka& H2O(s) * $aga& k" *a& H2O(g) * $aga& ka&a&, aka o
!"saaa& 1 '!'a
o
!"saaa& 2 '!'a ka"!&a H2O(g) s#*a% * s!$!la% ka&a&
o
!"saaa& 3 *$alk aga" H2O(s) $!"a*a * s!$!la% k"
H2O(s) → H2O(l) ; ΔH = + 1,4 kkal --- 'a&*a !&a* + ka"!&a *$alk *$alk
9!la&#'&a s#s#& *a& #la%ka& "!aks-"!aks '!"s!$#' s!$aga $!"k#' H2O(l) → H(g) H(g) + ½ O2(g) ; ΔH = + 68,3 kkal H(g) + ½ O2(g) → H2O(g) H2O(g) ; ΔH = - 57,8 kkal H2O(s) → H2O(l) ; ΔH = + 1,4 kkal :::::::::: ::::::::::::::: ::::::::: :::: + H2O(s) → H2O(g) ; ΔH = + 11,. kkal --- s 2 (UAN 2006/2007) 2006/2007) k!'a%# k!'a%# !&!"g !&!"g ka'a& ka'a& "a'a-"a'a "a'a-"a'a = 146 kkal/l - 83 kkal/l -H .. kkal/l -l 7. kkal/l H-l 103 kkal/l aka !"#$a%a& !&'al a*a "!aks
2H4(g) + Hl → 2H4l(g) a*ala% A -510 kkal +510 kkal +72 kkal -42 kkal -12 kkal Pembahasan : konsep energi ikat U&'#k sal s!!"' &, aka& sa&ga' !$a&'# ka k'a s#s#& s'"#k'#" l!<s&a '!"l!$% *a%#l# #&'#k !&!&'#ka& ka'a&&a a ka s#*a% la&>a" ka, '*ak %a"#s !$#a' s'"#k'#" l!<s#& $asa&a s#*a% !&g!"' !"k#' s'"#k'#" l!<s "!aks * a'as
!"*asa"ka& k&s! !&!"g ka', aka ΔH" = ?!&!"g !#'#sa& ka'a& - ?!&!"g !$!&'#ka& ka'a& !#'#sa& 4 -H = 4 (..) = 3.6 kkal/l 1 = = 1 (146) = 146 kkal/l 1 H-l = 1 (103) = 103 kkal/l :::::::::::::: + ? = 645 kkal/l !$!&'#ka& 5 -H = 5 (..) = 4.5 kkal/l 1 - = 1 (83) = 83 kkal/l 1 -l = 1 (7.) = 7. kkal/l :::::::::::::: + ? = 657 kkal/l aka ΔH" = ?!&!"g !#'#sa& ka'a& - ?!&!"g !$!&'#ka& ka'a& ΔH" = 645 - 657 ΔH" = -12 kkal/l @a* #&'#k 1 l a' ΔH" = -12 kkal --- s 3 (UAN 2008/200.) @ka *k!'a%#
ΔHB H4 = -75 k@/l ΔHB O2 = -3.3 k@/l ΔHB H2O = -242 k@/l aka ΔH "!aks !$aka"a& gas H4 !&#"#' "!aks H4 + 2O2 → O2 + 2H2O a*ala% A -1040 k/l -802 k/l -445k/l +8.0 k/l +1040 k/l Pembahasan : Konsep Hukum Hess ΔH"!aks = ?ΔH %asl - ?ΔH !"!aks ΔH"!aks = (ΔHB O2 + 2ΔHB H2O) - ( ΔHB H4) ΔH"!aks = (-3.3 + 2(-242)) - (-75) ΔH"!aks = -802 k/l --- s
!'!"a&ga& U&'#k #&s#"-#&s#", ΔHB = 0 aka ΔHO2 = 0 *a& '*ak *as#kka& *ala !"%'#&ga& 4 (UAN 2011/2012) !"%a'ka& !"saaa& "!aks '!"ka $!"k#'C 1 Nal(s) → Na(s) + ½l2(g); ΔH = + A k@/l 2 H4(g) + 2O2(g) → O2(g) + 2H2O(g) ΔH = - k@/l 3 ½N2(g)+ 3/2H2(g) → NH3(g) ; ΔH = - k@/l 4 H2(g) + ½O2(g) → H2O(l) ΔH = - k@/l 5 2(s) + 3/2H2(g) + ½O2(g) → 2H5OH(l) ; ΔH = - k@/l !"saaa& "!aks a&g !"#aka& ΔHB , ΔH*, *a& ΔH> a*ala% A 1, 2 *a& 3 1, 2 *a& 4 2, 3 *a& 4 3, 4 *a& 5 3, 1 *a& 2 Pembahasan : Menganalisis persamaan termokimia ΔHB !&#&#kka& "!aks !$!&'#ka& ΔH* !&#&#kka& "!aks !&g#"aa& ΔH> !&#&#kka& "!aks !$aka"a&
1 Nal(s) → Na(s) + ½l2(g) --- !&g#"aa& Nal 2 H4(g) + 2O2(g) → O2(g) + 2H2O(g) --- !$aka"a& H4 3 ½N2(g)+ 3/2H2(g) → NH3(g) --- !$!&'#ka& NH3 4 H2(g) + ½O2(g) → H2O(l) --- !$!&'#ka& H2O 5 2(s) + 3/2H2(g) + ½O2(g) → 2H5OH(l) --- !$!&'#ka& 2H5OH @a* s a&g '!a' a*ala% 3, 1, *a& 2 --- s
