Question

repede va rog frumos este urgent

Answer 1

reactia chimica:

NaOH+HCl->NaCl+H2O

mereu se lucreaza cu md, in cerinta ne da:
ms1=400g HCl de c1=36,5%
ms2=400g NaOH de c2=28%

36,5/100=md1/400=>md1=146g HCl
28/100=md2/400=>md2=112g NaOH
substanta in exces este:

n1=4 moli HCl
n2=2,8moli NaOH,dar 1molHCl reactiomeaza cu 1 mol de NaOH=>(4-2,8=)1,2moli HCl in exces

masa de apa:
1 molNaOH.......1mol H2O
2,8moli NaOH.....x
x=2,8moli H2O
masa molara H2O=1*2+16*1=18 g/mol
m=n*M=2,8*18=50,4 grame de apa

masa de sare(NaCl):
1molNaOH......1molNaCl
2,8moli NaOH.....y
y=2,8 moli NaCl
masa molara NaCl=23*1+35,5*1=58,5g/mol
m=n*M=2,8*58,5=163,8 grame de sare