Question

DAU COROANA + MULTE PUNCTE !
1 : Calculati compozitia procentuala si formula chimica a substantei H : P : O = 3 : 31 : 64
2: Ecuatiile dintre + de egalat reactiile : cupru + azotat de argint
calciu + oxigen
reactia de descompunere a cloratului de potasiu (KCLO3)
reactia dintre clorura de fier (2) si hidroxid de potasiu

Answer 1

1 .  3+31+64 = 98    %H = 3/98 ·100 =3,06%   ; %P=31·100/98 = ;31,63%
%O=64/98·100= 65,3%
element              masa                       nr. de atomi             formula
     H                         3                              3/1 = 3
     P                       31                             31/31 = 1
     O                      64                               64/16 = 4           
                                                                                             H3PO4
2. Cu + 2AgNO3 ⇒ Cu(NO3)2 + 2Ag
2Ca+O2 ⇒2CaO
 2KClO3⇒ 2KCl + 3O2
FeCl2 = 2KOH ⇒ Fe(OH)2 + 2KCl