Appendix

1086 Analytical Chemistry 2.0Appendix 8: Recommended Primary StandardsAll compounds should be of the highest available purity. Metals should be cleaned with dilute acid to removeany surface impurities and rinsed with distilled water. Unless otherwise indicated, compounds should be driedto a constant weight at 110 o C. Most of these compounds are soluble in dilute acid (1:1 HCl or 1:1 HNO 3 ),with gentle heating if necessary; some of the compounds are water soluble.Element Compound FW (g/mol) Commentsaluminum Al metal 26.982antimony Sb metal 121.760KSbOC 4 H 4 O 6 324.92 prepared by drying KSbC 4 H 4 O 6 •1/2H 2 O at110 o C and storing in a desiccatorarsenic As metal 74.922As 2 O 3 197.84 toxicbarium BaCO 3 197.84 dry at 200 o C for 4 hbismuth Bi metal 208.98boron H 3 BO 3 61.83 do not drybromine KBr 119.01cadmium Cd metal 112.411CdO 128.40calcium CaCO 3 100.09cerium Ce metal 140.116(NH 4 ) 2 Ce(NO 3 ) 4 548.23cesium Cs 2 CO 3 325.82Cs 2 SO 4 361.87chlorine NaCl 58.44chromium Cr metal 51.996K 2 Cr 2 O 7 294.19cobalt Co metal 58.933copper Cu metal 63.546CuO 79.54fluorine NaF 41.99 do not store solutions in glass containersiodine KI 166.00KIO 3 214.00iron Fe metal 55.845lead Pb metal 207.2lithium Li 2 CO 3 73.89magnesium Mg metal 24.305manganese Mn metal 54.938