Perform the following mathematical operations, and express the result to the correct number of significant figures. a. = b. = C. = d. = e. = f. =

5. Given the following reaction: C6H12O6 + 0₂--> CO₂ + H₂O a. Balance the equation b. Determine the number of grams of water produced when 1.68 g of C6H12O6 (glucose) is oxidized.

6. Urea (CH4N₂O) is a common fertilizer that is synthesized by the reaction of ammonia (NH3) with carbon dioxide (CO₂). 2 NH3 + CO₂--> CH4N₂O + H₂O In an industrial synthesis of urea, a chemist combines 1.364 X 10^5 g of NH3 with 2.114 X 10^5 g of CO₂. The reaction was performed and 1.684 X 10^5 g of urea was obtained. Determine the limiting reactant, theoretical yield, and percent yield for the production of urea.

1. (a) How is the percent copper determined in this experiment ? (b) What is the chemical reaction and the mole ratio between oxalate and permanganate in the titration reaction ? Chemical reaction: _______________________________________ Mole ratio: _______________________ C₂04² : _________________ MnO4 (c) How is the percent water determined in this experiment?

3. Briefly discuss the safety precautions related to this experiment. (chemical and equipment related)

TITLE PAGE INTRODUCTION: (the usual...) clearly state the purpose and explain the chemistry(i.e. define the Law !) - do not simply list calculations PROCEDURE: in PARAGRAPH form (3rd person past tense !)... explain the actual procedure done - don't just copy from the lab manual DATA: all data is contained on the lab computer printout - attach the printout HERE ! CALCULATIONS: show equations and calculations of all predicted volumes and % oxygen - give equations used, plug in data, show calc and final result... use units, sig figs & labels GRAPH: report quality graph...you can use the lab graph as long as you followed the directions given on lab handout DISCUSSION: as usual...state results (remember there were 2 parts to this experiment...hence, 2 results)...Give the true balanced equation for the reaction... compare results to expected & comment...give 3-4 sources of experimental error and how those errors would affect the results.

Buffers Substances that change_____in pH. _____H+ when pH is to low (acidic). _______H+ when pH is to high (basic).

1. Write the electron configuration and the orbital diagram for the following elements. Then, state how many valence electrons it has. A. Ca B. Fe C. Cl-1 D. Li E. Mg+2

3. Explain what evidence indicated a reaction took place for each of the reactions.

02 Question (4 points) 1st attempt Part 1 (2 points) I've discovered a new material! Its entropy of vaporization is 322.5 J/mol-K and its enthalpy of vaporization is 580 kJ/mol. Which of the following is TRUE? Choose one: O Vaporization always decreases entropy of a system. O Vaporization always increases entropy of a system. O Vaporization at high temperatures increases entropy of a system, but at low temperatures decreases entropy. O Vaporization at high temperatures decreases entropy of a system, but at low temperatures increases entropy. Part 2 (2 points) di See Periodic Table What is the vaporization point, in K, for this material? K