1)
M H2SO4=98
98g H2SO4.............6,023*10^23 molecule
1900g H2SO4..........X molecule
X=1900×6,023*10^23/98
X=31,066×10^25 molecule H2SO4
2)
M HCL=36,5
36,5 g HCl.........6,023×10^23
Y g HCl.......6,022×10^26
Y=36,5×6,022×10^26/6,023×10^23
Y=36493,9399g HCl
3) 382 g Cu3(PO4)2........1mol
Z g Cu3(PO4)2........4 moli
Z=382×4
Z=1528 g Cu3(PO4)2