a. c= n,moli/V,litri ,unde V=0,250l--------> inlocuieste!
b.aplici aceeasi formula ,dar calculezi moli
,n= 400g/40g/molNaOH....V se da
c. aplici aceeasi relatie,dar calculeazi
n=196g/(2gH+_32gS+4x16gO)/mol
v= m/ro---> v=200g/1,84g/cmcub=====> transformi in l impartind la 1000