nomer 2 sama nomer 4 gimana ya, tolong dong

2) Mol Mg(OH)2 = gram ÷ Mr = 58 : 58 = 1 mol
Mol HCl = 2/1 x mol Mg(OH)2 = 2 mol (perbandingan koefisien)
Massa HCl = mol x Mr = 2 x 36,5 = 73 gram

4) Propana = 8 liter, Volume sebanding dengan Mol, Propana = 8 mol
Mol CO2 = 3/1 x mol Propana = 24 mol (perbandingan koefisien)
Volume CO2 (STP) = 24 x 22,4 = 537,6 liter