Author: Anonymous

Deductive reasoning starts with general premises and applies them to specific cases to arrive at a conclusion.

What was the widely accepted hypothesis of inheritance during Mendel’s time?

True or False. Evolution is goal-oriented, moving toward perfection.

In a controlled experiment, what does the control group receive?

21.  (WCSU25.[x]) The ocean is said to contain one hundred trillion million dollars of gold (Au) in the form of gold(III) chloride.  For decades, chemists (and wannabes) have attempted to precipitate gold from seawater, albeit unsuccessfully.  One method would be to form an insoluble gold salt. Then, by a redox reaction, reduce the gold ions to pure gold ($$$!). a.  (6 points) In theory, sodium hydroxide could be used to precipitate gold from seawater.  Write the net ionic equation for the reaction below. Start with the complete ionic equation and identify spectators. AuCl3(aq)    +   3 NaOH (aq) ⟶  Au(OH)3 (s)     +    3 NaCl (aq)   b.  (4 points) Provide an alternative anion to hydroxide that could be used to precipitate gold in a similar reaction.  Write the formula of the insoluble product.  Explain in a few words how you selected the ion.   c. (12 points) You want to test the reaction in the lab before you head out to the ocean.  Calculate the mass (in g) of solid gold hydroxide (MW = 247.99 g/mol) that would form if 30 mL of a 0.200 M AuCl3 solution was mixed with 0.75 g of solid NaOH (MW = 40.0 g/mol). SHOW ALL WORK.   d.  (5 points) Calculate the percent yield if 0.98 g of precipitate are formed. (If you are unable to reach an answer in part c, you may use 3.0 g as the theoretical yield.)   Enter the percent yield in the box below.

Why is repeatability important in scientific experiments?

A group of different species living in the same area is called a:

14. (WCSU25.[x], 9 points) Draw the Lewis structures of the following molecule/ion. a. BH3 b. COCl2 c. SO42-   Enter the total number of lone pairs in all structures (a+b+c) below.

Put the following steps of prokaryotic transcription in order.

Put the following steps of DNA replication of the leading stand in chronological order.