anorganica probleme, semestrul 1

1.ECHIVALENTUL -GRAM A Ca3(PO4)2
M=4*30+31*2+16*8=310
E=M/E=310/6=51.66g
2. care este normalitatea unei solutii KOH 20% ,p=1.119g/ml
M=39+1+16=56
E=M/E=56/1=56
N=10*1.19*20/56=4.25Eg/l
3.Ce cantitate de H2C2O4 este necesara pt a prepara 300g solutie 10%
c%=100*md/ms
10% =100* md/300
md=3*10=30g
4.prin amestecarea a 100g solutie de KCl 3% cu 200g
solutie KCl 15% se obtine in final o concentratie de:
c%=md/ms*100
3%=md/100*100
md=3g
15%= md/200*100
md=30g
md f=3g+30g=33g
msf=100+200=300
c%=md/ms*100
c%=33/300*100=11%
5.normalitatea a 500 ml solutie H2So4 ,0.2 M este
m=1000*md/M*Vs
0.2=1000*md/98*500
md=98*0.2/2=9.8
N=1000*md/E*Vs
N=1000*9.8/49*500=0.4 N
6200 ml de solutie HNo3 solutie de 1N se dilueaza
cu apa distilata pana cand columul final al asol este 5 litri
md=N*Vs*Es/1000
M HNO3=1+14+48=63
Es=M/1=63/1=63
md=1*200*63/1000=12.6
N=1000*md/Es*Vs
N=1000*12.6/63*5000=0.04N
7. pentru prepararea a 400 g de solutie de Nacl 20% ,Nacl 15%
si nacl 10% sunt necesare urmatoarele cantitati
20%-15%=5 parti
20%-10%=10 parti
10+5=15 parti
15................400 g sol
5 parti...........x g
10 parti..........y g
x=5*400/15=133.33
y=10*400/15=266.66
8.z=17
1s2 2s2 2p6 3s2 3p5
grupa a7-a perioada a3-a