2 The table shows melting and boiling points for four substances. In which are the particles in an ordered arrangement at room temperature? Circle letter A, B, C or D.
melting point/"C boiling point/"c
A
- 115
79
B
-91
-88
с
SO
218
D
-23
77

Question

Химия: 2 The table shows melting and boiling points for four substances. In which are the particles in an ordered arrangement at room temperature? Circle letter A, B, C or D. melting point/ C boiling point/ c A - 115 79 B -91 -88 с SO 218 D -23 77

Арти2004 · Accepted Answer

Fe + H2SO4 = FeSO4 + H2 (1)
Mg + H2SO4 = MgSO4 + H2 (2)
1)    пусть m(Fe) = xг, тогда n(Fe)= x/56 моль; Тогда m(Mg)= (5,12 –x) г, n(Mg)= (5,12-х)/24 моль.
2)      масса (FeSO4) = у г, тогда n(FeSO4)= y/152 моль, тогда m(MgSO4)= (20,48 – y) г, n(MgSO4) = (20,48 - y)/120 моль;
3)      Из (1) х/56 = у/152; у = 152х/56 =19х/7;
4)
Из (2) (5,12-х)/24 = (20,48 –у) /120; подставив значение у во второе уравнение, получим х- 2,24 г (масса железа),
тогда масса магния = 5,12-2,24 =2,88 г.
5)      W(Mg)= 2,88*100%/5,12= 56,25%

2 The table shows melting and boiling points for four substances. In which are the particles in an ordered arrangement at room temperature? Circle letter A, B, C or D. melting point/"C boiling point/"c A - 115 79 B -91 -88 с SO 218 D -23 77

MOGZ ответил

2 The table shows melting and boiling points for four substances. In which are the particles in an ordered arrangement at room temperature? Circle letter A, B, C or D.
melting point/"C boiling point/"c
A
- 115
79
B
-91
-88
с
SO
218
D
-23
77