In order to determine the identity of a particular lanthanide metal (M), a voltaic cell is constructed at 25°C with the anode consisting of the lanthanide metal as the electrode immersed in a solution of 0.0467 M MCl3, and the cathode consisting of a copper electrode immersed in a 1.00 M Cu(NO3)2 solution. The two half-reactions are as follows:

M(s)  M3+(aq) + 3e–

Cu2+(aq) + 2e– Cu(s)
The potential measured across the cell is 2.70 V. What is the identity of the metal?

Reduction Half-Reaction

E° (V)

Cu2+(aq) + 2e– Cu(s)

0.34

Ce3+(aq) + 3e– Ce(s)

–2.336

Tm3+(aq) + 3e– Tm(s)

–2.319

Eu3+(aq) + 3e– Eu(s)

–1.991

Gd3+(aq) + 3e– Gd(s)

–2.279

Sm3+(aq) + 3e– Sm(s)

–2.304

Tm

Gd

Ce

Eu

Sm

Given 7.65 g of butanoic acid and excess ethanol, how many grams of ethyl butyrate would be synthesized, assuming a complete 100% yield?

The number at the end of an isotope’s name is the number.

98 points you will be galileo perform the experiment to determine if objects with different mass fall at the same, or different, rates in the air and in a vacuum. before you conduct your experiment, you need to form a hypothesis. a hypothesis is a prediction of what you think will happen in the experiment. the hypothesis is a statement that describes “if” a certain set of circumstances are present “then” there will be a specific result that will occur. record your hypothesis here: record the results from step one of the experiment (dropping the objects in the air): first trial: second trial: third trial: record the results from step two of the experiment (dropping the objects in a vacuum): first trial: second trial: third trial: did the experiment support your hypothesis? using the data from your experiment, describe why you believe your hypothesis was either proven or disproven. what forces were acting on the objects dropped in the air? what force was acting on the objects dropped in the vacuum? part two: comparing forces choose two forces and compare and contrast these forces. you must provide two ways that they are alike and two ways that they are different. you may make a list, write in paragraph form, or make a chart. choose two forces and compare and contrast these forces. these must be different forces than used in the prior question. provide two ways that they are similar and two ways that they are different. you may make a list, write it out, or make a chart.