"100molekuli" - 1 õppematerjal

Üldloodusteadus

n( H 2O ) = = = 1,67(mol ) M 18 b)m(C6 H 6 ) = V = 0,88 200 = 176( g ) M (C6 H 6 ) = 12 6 + 1 6 = 78( g / mol ) m 176 n (C 6 H 6 ) = = = 2,3(mol ) M 78 N 100 c )n(C6 H 6 ) = = = 16,67 10 -23 (mol ) 22) N A 6 10 23 Antud: a)V=30ml b)V=200ml p(C6H6)=0,88g/cm3 c)N(C6H6)=100molekuli a)n(H2O)=? b)n(C6H6)=? c)n(C6H6)=? Vastus: a)n(H2O)=1,67mol; n(C6H6)=2,3mol; n(C6H6)=16,67×10-23mol. n CM = n = CM V V N = n N A N = CM V N A N ( Na2 SO4 ) = 0,35 0,2 6 10 23 = 0,42 10 23 = 4,2 10 22 (kristallit ) N ( Na + ) = 4,2 1022 2 = 8,4 10 22 (iooni ) 2- 23) N ( SO4 ) = 4,2 10 (iooni ) 22 V = 200ml = 0,2l M ( Na2 SO4 ) = 23 2 + 32 + 16 4 = 142( g / mol ) m 10