Question

cine imi rezolva dau coroana

Answer 1

1/.

cunoastem

Vs = 100 ml = 0,1 L, Cm = 2 M, ro = 1,1 g/cm3 (g/ml)

V.apa = 100 ml = 0,1 L

stim relatiile:

Cm = md/miuxVs

c% = mdx100/ms

ro = ms/Vs

din Cm => md = CmxmiuxVs

miu.NaOH = 40 g/mol

=> md = 2x0,1x40 = 8 g NaOH

din ro => ms = roxVs

= 1,1x100 = 110 g sol. NaOH

ms.final = ms + m.apa = 110 + 100 = 210 g sol. NaOH

=> c% = 8x100/210 = 3,81%

2/.

din legea de stare a gazelor PV = nRT

=> V = nRT/P

n = 560/28 = 20 moli

R = 0,082

T = 273+27 = 300 K

P = 2 atm

=> V = 20x0,082x300/2

= 246 L N2