7.  A chromatography experiment was used to determine components in a mixture. a.  Calculate the Rf values for spot A and spot B using your ruler. Show your work. Use appropriate significant figures in your measurements and calculations.  (6 points, WCSP24.[x])    b. The stationary phase for the previous chromatogram was cellulose, which is highly polar due to the presence of multiple hydroxyl (OH) groups.  The mobile phase was water.  Given this, identify which amino acid (a building block for proteins) shown below corresponds to A and B.  Explain your reasoning. (6 points)   Enter the Rf value of spot A in the box below.

19.  (WCSP[x], 5 points) Hydrogen bonding is responsible for many of the interesting and unusual properties of water. Draw a picture showing hydrogen bonding in liquid water.  Use three water molecules in your drawing and dashed lines to depict the hydrogen bonding interactions. Enter the number of hydrogen bond donor-acceptor interactions in the sketch.  

(WCSP24) Explain the “like dissolves like” principle. Use at least two specific examples in your explanation.

In the 1910s, a massive immigration of blacks from south to north occurred as a result of

Whenever Jamia sees someone wearing traditional Middle Eastern clothing or a woman with a hijab, she gets very upset. She will cross the street to avoid them and turn down another aisle in the store to avoid them. If she accidentally comes close to someone she believes is Muslim or Middle Eastern she gets nervous and has to leave immediately. What is Jamia experiencing?

Which of the following contributed least to anti-Catholic attitudes in 19th century America?

According to Terry’s up/down metaphor which of the following persons would be exclusively a member of “down” groups?

The primary difference between being a refugee and an immigrant is that refugees are defined as immigrants who are

What is the first step and most basic tactic when trying to promote social change?

What happens to the native language of immigrants in the United States after a few generations?