Mavzu: Moddalarning berilgan massasi ulushi, foiz ulushi aniqlash, murakkab moddalarning formulalarini keltirib chiqarishga oid masalalar

22-masala. 3 mol massasi 96 gr bo`lgan moddani toping?
3mol----------96 gr
1mol-----------x=32gr O<sub>2</sub>
23-masala. 0,5 mol massasi 32 gr bo`lgan moddani toping?
0,5mol---------32 gr
1mol-----------x=64 gr Cu
24-masala. 12 mol massasi 24 gr bo`lgan moddani toping?
12mol-----------24gr
1mol--------------x=2 gr H<sub>2</sub>
25-masala. 0,5 mol massasi 31,5 gr bo`lgan moddani toping?
0,5mol--------------31,5 gr
1mol--------------x=63 gr HNO₃
Mavzu: Mol. Modda miqdori mavzusiga oid masalalar yechish
Mol.Modda miqdori. Molyar massa-bu modda massasining modda miqdoriga bo’lgan nisbatidir. M= ; m—massa, (gr) n-miqdor(mol),
M-molyar massa (gr\mol)
1-masala: Massasi 10,8 gr bo’lgan metal namunasida alyuminiy
moddasi qanday miqdorni egallaydi?
Yechish: M(Al)=27 gr\mol ekanligini bilamiz, bu masalani ishlashda
ushbu formuladan foydalanib hisoblaymiz:
n (Al)= n=10,8\27=0,4 mol.
Javob: 0,4 mol


2-masala:Massasi 50,8 gr bo’lgan molekulyar yodda qancha
struktura birlik bor?
Yechish:
n(J₂)= n J₂=50,8\254=0,2 mol
N(J₂)=0,2·6,02·1023=1,2·1023
3-masala: 0,25 mol miqdordagi moddaning massasi 26,5 gr bo’lsa
uning molyar massasini hisoblang?
Yechish: Mr=m/n
Mr =26.5/0.25=106
Javob: Mr =106gr/mol
4-masala: 28,2 gr K₂O dan qancha massa potash olish mumkin.
Yechish:
K₂O +CO₂= K₂CO₃

28,2 -----------x=41.4g

94gr (K₂O)---------- 138 gr (K₂CO₃)

5-masala.3 mol H₄P₂O₇ va 5 mol H₂Cr₂O₇ tarkibidagi element atomlar
nisbatini hisoblanag?
Yechish :
3 mol ------- x 5 mol -------- x
H₄P₂O₇ H₂Cr₂O₇
1 mol ------- 13 ta 1 mol -------- 11 ta
x= 39 ta atom bor x = 55 ta atom bor
39: 55 39 : 39
1 : 1,4