Question

Be sure to answer all parts. Calculate the number of cations and anions in each of the following compounds. Enter your answers in scientific notation. (a) 7.73 g of KBr: x 10 cations anions (b) 4.61 g of Na,so: anions (c) 6.16 g of Ca3(PO4)2: anions

Answer 1

Answers a) 7.73 g of KBY {KBr - kt & Br) moles of KBr = mass molar mass of KBY 7.73 119.002 0.0649 mel moles of kt cations = 1, moles of KBV - 1x 0.0649 - 0.0 6 4 9 mol Number of Kt cations = moles & Avogadro's number - 0.0649 x 6.022 x 1003 3.908 x 1ood cations moles of Br anions - ix moles of key = 1X 0.0699 - 0.0649 Number of By anions = moles X moles x AVOS Avogadro's number 6.00 ? x 103 - 0.0649 X 3.908 x road Anions.

b) 4.61 g of Nad so a (Naso - dovat & sogg moles of now so = mass molar mass of oua so 4.61 142.04 0.0324 moll motes of ovat cations = ax moles of ongeso = 2 X 0.0344 0.06 48 mol Number of ovat cations = moles x Avogadro's number - 0.0646 X 60 X 3 3.902 X 1ood cations moles of soa- anions = 1x moles of walso = 1x 0.0804 = 0.0324 mol number of son anions = moles x Avogadro's number - 0.0324 x 6.oda xoQ3 - 1.951 x 1002 Anions

c) 6.16g of ca, Potha (caroa) - 3 cat & & po 3 moles of caz (PA) = mass molar mass of ca, pot) 6.16 310.18 0.0198 mol - 8x moles of caz (Pof) moles cart cations of = 3x o.olag - 0.0 594 mol number - moles x Avogadro's number of colt cations = 0.0594 x fiodd x 1083 cations 3.577 x 10.2 moles of pop onions = 2x moles of cas (Pot) 2x 0.0198 0.0396 mol Number of por anions = moles & Avogadro's number 6.oda x 1093 0.0396 * - 3,384 Xlope anions