Ag2S forms a black precipitate and CdS forms a dark yellow precipitate. A solution of CdS is prepared by dissolving 0.25 moles of solid CdS in distilled water. When equilibrium is established, a small amount of dark yellow solid remains on the bottom. A 0.25 mol if solid AgNO3 is then stirred into the beaker, and the dark yellow precipitate is replaced with a black precipitate. I. Did the following equilibrium shift after the AgNO3 was added? Explain using 2-3 sentences.

CdS (s) equilibrium arrows Cd 2+ (aq) + S 2- (aq)

II. Which compound has the larger Ksp value? Justify your answer.

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)

What is the percentage of hydrogen in c2h4

The data below were determined for the reaction shown below. s2o82– + 3i – (aq) → 2so42– + i3– expt. # [s2o82–] (m) [i –] (m) initial rate 1 0.038 0.060 1.4 × 10 – 5 m/s 2 0.076 0.060 2.8 × 10 – 5 m/s 3 0.076 0.030 1.4 × 10 – 5 m/s the rate law for this reaction must be: