Question

cine mă poate ajuta ,si daca imi puteti explica?!

Answer 1

1)

ms=400 g

md=80 g

c=?

c=md•100/ms=80•100/400=20%

2)

c=md•100/ms

md=75 kg sodă

ms=500 kg soluție

c=75•100/500=15%

3)

c=15%

md=60 kg

c/100=md/ms

15/100=60/ms=>ms=100•60/15

ms=400 kg

4)

c=md•100/ms

md=2 kg sare

c=4%

ms=md•100/c=2•100/4=50 kg soluție

5)

ms=50 g

c=8%

md=?

md=c•ms/100=8•50/100=4 g

6)

ms=20 kg

c=1,5%

ms=?

ms=1,5%•20 kg/100%=0,3 kg

7)

md=25 g

m apă=475 g

c=md•100/ms

ms=md+m apă

ms=25 g+475 g=500 g

c=25 g•100/500 g

c=2500/500=5%

8)

m apă=320 g

md=80 g

c=?

ms=md+m apă=80+320=400 g

c=md/ms•100=80/400•100=20%

9)

c=md•100/ms

md=300•16/100=48 g dizolvat

ms=md+m apă

m apă=300-48=252 g apă

10)

c=12%

md=60 g

m apă=?

c/100=md/ms

12/100=30/ms

=>ms=60•100/12=500 g

ms=md+m apă

500=60+m apă

m apă=520-60=440 g

11)

c1=md1/ms1•100

md1=c1•ms1/100

md1=40 g

c2=md1/ms1+m apă

ms1+m apă=md1•100/c2

200+m apă=400

m apă=400-200

m apă=200 g

12)

ms=400 g

c=16%

md=400•16/400=4•16=64 g

ms2=400 g+200 g=600 g

c2=64•100/600=64/6=10,(6)%

13)

c/100=md/ms

12/100=md/400=>md=12•400:100=48 g

c dublă=12•2=24

24/100=md/ms=48/ms

ms=100•48:24=200 g

ms cu c=24%

400-200=200 g apă

14)

100 g soluție___________20 g substanță_____________80 g apă

Dacă se evaporă 100 g apă

Rămân 40 g soluție____________100 g substanță

100 g soluție___________x

x=25%

15)

md1=40•10:100=4 g

md2=30•40:100=12 g

md3=md1+md2=4+12=16 g

ms3=ms1+ms2=40+40=80 g

c3=md3/ms3•100=16/80•100=20%

16)

ms1=200 g

c1=20%

c1=md1/ms1•100<=>md1=c1•ms1/100=40 g

ms2=200 g

c2=10%

=>c2=md3/ms2•100<=>md2=c2•ms2/100=20 g

c finală=md1+md2/ms1+ms2+m H2O•100=40-20/200+200+200•100=60/600•100=10%

17)

c=md•100/ms

md=40•13/100=5,2 kg dizolvat

ms=md+m apă

m apă=40-5,2=34,8 kg apă

18)

md=39 g

c=13%

c=(md/md+m H2O)•100

13=(39/39+m H2O)•100

13(39+m H2O)=3900

507+13 m H2O=3900-507

13 m H2O=3393:13

m H2O=261 g

19)

md/ms•100=c

c=5%

md=x

ms=475 g+x

x/(475+x)•100=5=>

=>100x/(475+x)=5=>

100x=2375+5x=>

=>95x=2375=>

=>x=2375/93=>

=>x=25 g

20)

c=md/ms•100=>

md=c•ms/100=10•200/100=20 g NaCl

ms=md+m H2O=>m H2O=ms-md=200-20=180 g

md=(c•m H2O)/(100-c)=20•180/100-20=45 g NaCl

m NaCl adăugat=45-20=25 g NaCl

Data viitoare,te rog frumos să pui mai puține probleme.