4.00 mL of 7.00 x 103 M Fe(NO3)3 (7.00 times 10 to the minus 3rd power M Fe (NO3)3) is added to 6.00 mL of 7.00 x 103 M KSCN (7.00 times 10 to the minus 3rd power M KSCN) along with 4.00 mL of water. The concentration of [F e(SCN)2+] was found to be 2.00 x 10-3 M (2.00 times 10 to the minus 3rd power M) at equilibrium. How many initial moles of F e3+ are present in the solution? Express your answer as a decimal number (no exponents). Your Answer:

Solid Pbl2 (Ksp = 9.8 109) is placed in a beaker of water. After a period of time, the lead(II) concentration is measured and found to be 1.1 103 M. Has the system reached equilibrium? That is, is the solution saturated? If not, will more Pbl2 dissolve?

A few drops of each of the indicators shown in the accompanying table were placed in separate portions of a 1.0-M solution of a weak acid, HX. The results are shown in the last column of the table. What is the approximate pH of the solution containing HX? Calculate the approximate value of Ka for HX. Indicator Color of Hln Color of ln pKa of Hln Color of 1.0 M HX Bromphenol blue Yellow Blue 4.0 Blue Bromcresol purple Yellow Purple 6.0 Yellow Bromcresol green Yellow Blue 4.8 Green Alizarin Yellow Red 6.5 Yellow

In a titration of cyanide ion, 28.72 mL of 0.0100 M AgNO3 is added before precipitation begins. [The reaction of Ag+ with CN- goes to completion, producing the Ag(CN)2- complex. Precipitation of solid AgCN takes place when excess Ag+ is added to the solution, above the amount needed to complete the formation of Ag(CN)2-. How many grams of NaCN were in the original sample?

Write net ionic equations for the reaction of H+ with (a) Fe2S3 (b) Mg(OH)2 (c) MgCO3 (d) Pt(NH3)42+ (e) Hg2I2

Calculate the molar solubility of AgBr in 0.035 M NaBr (KSP=51013).

At 25C, 10.24 mg of Cr(OH)2 are dissolved in enough water to make 125 mL of solution. When equilibrium is established, the solution has a pH of 8.49. Estimate Ksp for Cr(OH)2.

Calculate the solubility in grams per 100 mL of BaF2 in a 0.10 M BaCl2 solution.

Calculate the equilibrium concentration of Zn2+ in a solution initially with 0.150 M Zn2+ and 2.50 M CN-.

The solubility of magnesium hydroxide in pure water is 1.3 x 10–4 mol/L. (a) Calculate the Ksp of Mg(OH)2; (b) What isthe pH of saturated Mg(OH)2solution at 25oC? (c) Calculate the solubility of Mg(OH)2 in a solution buffered at pH 9.0?