A class is given a demonstration of solution chemistry and solubility equilibria.Passage: A 6.57-g sample of NiSO4•6H2O (molar m
ass 262.84) is dissolved in enough water to make 50.00 mL of a green solution, and 7.15 g of Na2CO3•10H2O (molar mass 286.14) is dissolved in enough water to make 50.00 mL of a colorless solution. The two solutions are mixed, and a green precipitate forms. The resulting slurry is divided into two equal portions. To one portion is added an excess of 6 M HCl, which results in the disappearance of the precipitate and a rapid evolution of a gas. To the second portion is added a few milliliters of 6 M NH3. The precipitate dissolves, and a blue solution forms.Question: According to the information in the passage, the gas that evolves is:A) sulfur dioxide. B) sulfur trioxide. c) carbon dioxide. D) carbon monoxide.
There is two reactions taking place: first, nickel sulfate reacts with sodium carbonate yielding sodium sulfate and nickel carbonate, which is a green solid. Then nickel carbonate reacts with hydrochloride, yielding nickel chloride, carbon dioxide and water.
1. Na3PO4+Mg(NO3)2= NaNO3 + MgPO4 So this is not the answer. 2. Al+CuCl2= AlCl3+ Cu So this is the answer. 3. Mg+O2= MgO2 So this is not an answer 4. Cl2+KI= KCl+I2 So this is also an answer
The definition of <em>equilibrium</em> is when the forward rate and the reverse rate are <em>equal</em>.
Because in the initial state there's only NO₂, there's no possibility for the reverse reaction (from N₂O₄ to NO₂). Thus the forward rate will be larger than the reverse rate.
