(3b-101) Balance the following equations (be sure to first convert any chemical names into formulas). Show all steps for balancing or write a brief explanation of your mental process if you were able to balance it in your head. FeCl3 + NaOH → Fe(OH)3 + NaCI P+ 02 P205 Lead(II) hydroxide reacts with hydrogen chloride to produce water and lead(II) chloride. Zinc sulfide reacts with aluminum phosphide to produce zinc phosphide and aluminum sulfide.

Consider the reaction 3X + 2Y→ 5C + 4D How many moles of X are needed to produce 24.00 moles of D? If your answer is not a whole number, answer to the hundredths place.

One way the U.S. Environmental Protection Agency (EPA) tests for chloride contaminants in water is by titrating a sample of silver nitrate solution. Any chloride anions in solution will combine with the silver cations to produce bright white silver chloride precipitate. Suppose an EPA chemist tests a 200. mL sample of groundwater known to be contaminated with cadmium chloride, which would react with silver nitrate solution like this: CdCl₂(aq) + 2 AgNO3(aq) → 2 AgCl(s) + Cd(NO3)₂(aq) The chemist adds 75.0 mM silver nitrate solution to the sample until silver chloride stops forming. He then washes, dries, and weighs the precipitate. He finds he has collected 7.0 mg of silver chloride. Calculate the concentration of cadmium chloride contaminant in the original groundwater sample. Be sure your answer has the correct number of significant digits. mg L

There are two steps in the extraction of copper metal from chalcocite, a copper ore. In the first step, copper(I) sulfide and oxygen react to form copper(I) oxide and sulfur dioxide: 2Cu,S(s) 30,(8) 2Cu,0(s) + 2 SO, (g) In the second step, copper(I) oxide and carbon react to form copper and carbon monoxide: Cu,O(s) + C(s) 2Cu(s) + Co (g) Suppose the yield of the first step is 84.% and the yield of the second step is 95.%. Calculate the mass of copper(I) sulfide required to make 4.0 kg of copper. Be sure your answer has a unit symbol, if needed, and is rounded to the correct number of significant digits.