We have access to the complete dataset of all ages (in years) at death for First Ladies of the U.S. who have passed. From this data set we know that the average age at death is 71.7 years. You are interested in how the sample statistics vary for different samples of size n=15 from this population. A sampling distribution is constructed where one of the samples is used to create a bootstrap distribution. This sample has mean: x-bar = 78 years. Below are boxplots of the sample of size n = 15, the sampling distribution, and the bootstrap distribution (although not necessarily in that order!). Use all of the provided information to select the correct reason for each Boxplot identification. Boxplot A is the sampling distribution because it is centered at the and has a standard error that is roughly equal to the estimated standard error found with the . Boxplot B is the bootstrap distribution because it is centered at the and has an estimated standard error that is roughly equal to the standard error found with the . Boxplot C is the sample of n = 15 because it is centered at the where the sample standard deviation (s) is the value of the standard error found with the sampling distribution.

What is the mass in grams of MgCI₂ that can be produced from 0 moles of Cl₂ gas reacting with excess magnesium? Mg(s) + Cl₂(g) → MgCI₂(s)

Consider the reaction Mg2Si(s) + 4 H2O(l) → 2 Mg(OH)2(aq) + SiH4(g) Which of the reactants is in excess if we start with 50.0 g of each reactant? Show your work and explain your reasoning.

The fictional element Chaffium (symbol Ch) makes two oxyanions: ChO3¯ and ChO4¯ What would be the name of ChO4¯? Explain your reasoning. Note: The fictional element name is a Latin word that ends with -ium like many real elements. Just use the same rules as you would with a real element name.

Consider an element that has 3 naturally occurring isotopes. The isotopic masses and percent abundances are 53.9396 amu (5.845%), 55.9349 amu (91.754%), and 56.9354 amu.  What is the average atomic mass in amu of X? Show your work and give your answer to 2 decimal places.

Carl Fredricksen raised 80 sheep, then entered into a series of business transactions. He traded all the sheep for goats at an exchange rate of 5 goats for 7 sheep. Next, he exchanged all the sheep for hogs at a rate of 4 goats for 2 hogs weighing 225 lbs. each. He sold all the hogs at a market price of $60.00 per 100.0 lbs. How much money did he make from the 60 goats?  Show your work using dimensional analysis.

What would be the charge on an atom of nickel which only has 25 electrons? 

What would be the charge on an atom of gold which only has 78 electrons? 

A chemist is trying to identify an unknown metal and finds that 25.0 cm³ of the substance has a mass of 224.43 g at 20°C. Which of the following metals is it? Show your work.

For the reaction 2 CI2(g) + 4 NaOH(aq) → 3 NaCl(aq) + NaCIO2(aq) + 2H2O(I) 11.9 g CI2 is reacted with 12.0 g NaOH. Determine which is the limiting reactant. Show your work and explain your reasoning.