Question

Calculate the following quantities: (a) mass, in grams, of 1.50 x 10^-2 mol CdS (b) number of moles of NH4Cl in 86.6 g of this substance (c) number of molecules in 8.447 x 10^-2 mol C6H6 (d) number of O atoms in 6.25 x 10^-3 mol Al(NO3)3

Answer 1

as moles of cast 1.50x 10 mole. Molar Mass of cds= 144.46 gm/mot. so mass of sample= moles of cds x molae mass of cols = 1.50x10 mdex 144.46 gm note I mass of CdS = 2.1669 gm ] by Mass of NHA cl sample 86.6gm. Molah mass of NHA cl = 1814 + 4x 1+ 1x35.5 53.59mmel. Moles of NHA Cl = Mass of Sample 86.686 Molar mass of sample 53.5 pro/soof. Moles of NHA cl = 1.62 mole > Moles of CG HG = 8.447x10 mole. each mole have = 6.022 x 13 atoms. so, alomsor molecules in 8. 447x10 mole = 6.0228 12²x8.447x10² = 5:08781822 atoms (d) Moles of Al(Ng) = 6.25x10 mde each osole of Af (NO) have 3-mole of oxygen, so Number of mole of oxygen Eo]= 9x6.25x1 mole = 0.05625 mole. so Number of atoms = 0.05625 X 6.022, 103 atom O ators = 3.39x18 atoms