Question

GRAVIMETRIC ANALYSIS Gravimetric Analysis-A type of analysis in which a sample is subjected to some treatment that causes a change in the physical state of the analyte that permits its separation from the other components of the sample. Mass measurements of the isolated analyte used along with the known stoichiometry of the compounds involved, permit calculation of the analyte concentration. Commonly, the analyte is separated by subjecting it to a precipitation reaction. -EXAMPLE a) A 0.4550-g solid mixture containing MgS0, is dissolved in water and treated with an excess of Ba(NOs)lh. resulting in the precipitation of 0.6168 g of BaSO., according to the following reactien: BaSO (s) + Mg(NO,)2(aq) MgSOalaq)+ Ba(NOs)a(aq) What is the concentration (mass percent) of MgSo, in the mixture? What is the percent of chloride ion in a sample if 1.1324 g of the sample produces 1.0881g of AgCl when treated with excess Ag'? b) Ag'laq)+ C(aq) AgCl(s)

Answer 1

(57 molas mars 2 33.38 @ Givern Equations MgSO4 langt Ba (NO) BaSO4 + Mg News moles of BaSO4s) produced = 0.6168 = 0.6168 BaSO4 J = 2.64 X10 3 moles. How from above chemical Equation, Imole of M SO u ag trives & mole of BaSO4(s) 2.64 x103 mole of Mg (son dan Givedy 2.64 X103 moles of Basco A mole of Mg soyag) - 7 120.366 g i 2.64 x 103 mole of MgSO4 (ag) - 2.64X10 XR0.366 - 0.3181 grof Masoy. Gives How

low mass porcent = mass of Masou non total mass 6.3181 x 100 0.6168 = 51.57 % . Given Equation, Agtag + ce an Ageless moks produced = 1.0221 How Gives Aga 1.0881 molas mass of age 143-32 = 0.00759 = 7.59x103 miles. I mole of cr lues & Imole of ACI 7.59 x10 mole of cr - 7.59 x103 modes of Ag C. know 1 mole of ar 35.453 g. 7.59x10-3 mole of C -> (9-59X10* *35.453) galer = 0.269 9940 mass percent = mass oor x 100 we total mass 0.26 91 x 100 = 23.469 1. 1324
thank you vmuch

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