viernes, 19 de noviembre de 2010

Tarea quimica 5

                                               Tarea química 5.
Ejercicios de la hoja 3, 5 y 6.
Análisis cuantitativo:
3)                                   (NH4)2 Cr2 O7                             Cr2 O3+ N2+ H2O
#  Átomos             N= 1  H=8     Cr= 2  O=7                Cr= 2 O= 3 N=2 H= 2 O=1
# Moléculas          1 NHCrO 7                 1CrO3                1N2                      1H2O               
# Moles                  1 NHCrO 7                1CrO3                 1N2                     1H2O
Gramos                  179.01 gr                  100 gr                 28 gr            33.008 gr
                                                                                                   = 161.008 gr 
Clasificación y balance:
a (NH4)2 Cr2 O7           b Cr2 O3 +  c N2  +d  H2O=  Descomposición.
N= 2                                  Cr= 2       N= 2     H= 2
H= 8                                 O= 3                       O= 1
Cr= 2
O= 7

Para N
2a= c                                                           a= 1
Para H                                                         b= 2
3a + b= 2c + d                                            c= 2
Para  Cr                                                       d=  2/3
2a= 2d
Para O   b= 2c

5)                                 P4 O10 +  Mg(OH)2             Mg3(PO4)2 +H2O
# Átomos           P=4    O=10    Mg=1  O=2 H=2       Mg=3 P=2 O=8  H=2 O=1
# Moléculas       1PO10            1Mg(OH)2              1Mg(PO4)2         1H2O  
# Moles               1PO10            1Mg(OH)2             1Mg(PO4)2          1H2O
Gramos              190.97gr         42.326gr                 183.28 gr             18.016gr

a P4 O10+ b Mg (OH)2  →c Mg3 (PO4)2 + d H2O= Neutralización.
P=4                Mg=1                Mg=3                   H=2
O=10            O=2                    P=2                      O=1
                      H=2                  O=8
Para P
4a=c             1=4a
                    ¼=a
Para O
10a+ b= 2c + d                                          a= 1/4
Para Mg                                                     b= 6
B= 3c + 2d                                                 c= 3
B= 6                                                            d= 1/5
Para H
B= 3c


6)                          I2 O5    + BrF3                I F5 +       O2    + BrF2               
# átomos        I= 2  O=5     Br=1  F=3               I=1  F=5   O=2       Br=1   F=2
#moléculas      1IO5             1BrF3                    1IF5            1O2         1BrF2
# Moles          1IO5               1BrF3                     1IF5            1O2        1BrF2
Gramos          206.9gr         136.9gr                  221.9gr       32gr         117.9gr

I2 O5+ Br F3 IF5+ O2+ BrF2 =  Desplazamiento

viernes, 12 de noviembre de 2010

Tarea quimica 4


                                                  Tarea química 4.
Pagina 86:
3.39-    Sn- estaño                O- 16
              SnO2                       Sn- 118
                                               Pm- 134
% elemento=   masa del elemento/ Pm  *100
% Sn=   118q/134q   * 100
% Sn= 88.06
% O= 16*2/134  * 100
%= 23.881
Sn= 88.06%
O= 23.882%

3.41-      Ca H10 O                                                              C= 12*9= 108
                                                                                              H= 10
                                                                                               O= 16
a) C= 80.597%           H= 7.463%                                        O= 11.940%
    % C= 108/134  *100
    %C= 80.597

%H = 10/134  *100                                                       %O= 16/134  *100
%H= 7.463                                                                       %O= 11.940

  3.43-       a)        C= 44.4%                                        O= 9.86%
                           H= 6.21%
                           S= 39.5%                   
1) Convertir a moles:
44.4 g 1mol c/ 12g=   3.7 mol C
6.21g    1 mol H/1g= 6.21 mol H
39.5g     1 mol S/ 32g= 1.234 mol S
9.86g    1 mol O/ 16g= 0.616 mol O
Encontrar factor común:
C= 3.7 mol C/0.616 mol= 6.006 C
H= 6.21 mol H/ 0.616 mol= 10.08 H                        =            C6 H10 S2 0
S= 1.234 mol S/ 0.616 mol= 2.003 S
O= 0.616 mol O/ 0.616 mol= 1

b)  162g/ 162g= 1               =                     C6 H S2 O

Libro pagina 125:

4.53-  # gramos= M     V     Pm
            #gramos= (2.80)     (0.500 lt)     (87)
           #gramos= 121.8 gramos es la masa de IK.

4.55-  MaCl2 =  Cloruro de magnesio
                                      60.0 ml
                                      0.100 M
Ma= 24
Cl= 35*2=70
                 94 Pm                 
            Molaridad= # moles/ 1 lt sal
0.100 M= # moles/ 0.6 lt
0.100/ # moles= 0.6 H
Moles= 0.6/ 0.100 M=  # moles= 6
4.56:   Ko lt
            35.0 ml
            5.50 M
K= 39
O= 16              =56 Pm                            # gramos= 5.50 M     0.035 ml  * 56
H= 1                                                          #gramos= 107.8      
                                                                        107.8= 10.78 gr

4.59-  V= ?                                      Na= 23
                                                        Cl= 35                       =58
a) 2.14- NaCl
    0.270 M
                           # gramos= M  *V  *PM
                           #gramos= 0.270 *V * 58
                           2.14 g= 0.270 * V * 58  
                          2.14/58= 0.270 * V
                       2.14/0.270= 136.6 H
b)  4.30 g de estanol                       V=?
          1.50 M                            Estanol= C2 H S O H
C= 12*2= 24
H= 1*6= 6
O= 16= 16
              46 Pm                            430 g/ 1.50* 46= V
 0.0623 ml= V
623 lt= V

c) 0.85 g – acido acético= CH3 COO H
C= 12*2= 24
H= 1*4= 4                     = 60
O= 16*2= 32
0.85g/ 0.30*60= V
0.0472 ml= V
472 lt= V