A student attempted to identify an unknown compound by the method described in this experiment. When he heated a sample weighing 1.031 g the mass went down to 0.688 g. When the product was converted to a chloride the mass went up to 0.748 g. (Answers I got are in bold)

1.Explain if you believe the sample to be a carbonate or hydrogen carbonate. (I said it is a hydrogen carbonate due to the loss of mass)

2.Write the two possible chemical equations for the reaction that that you believe occurred; one for sodium and one for potassium (carbonate or hydrogen carbonate). (we are supposed to use these two formulas but I am not sure how: 2XHCO3→ X2CO3 + H2O + CO2 this is hydrogen carbonate X2CO3 + 2 H+ + 2 Cl-→ 2 XCl + H2O + CO2 This one is for the hydrochloric acid being added)

3.Show by calculation how many moles of the chloride salt would be produced from one mole of original compound; one for sodium and one for potassium (carbonate or hydrogen carbonate).

4.Fill out the following information to help you determine how many grams of the chloride salt would be produced from one molar mass of original compound?

If NaHCO3 ____________ g original compound → ____________ g chloride

If KHCO3 ____________ g original compound → ____________ g chloride

If Na2CO3 ____________ g original compound → ____________ g chloride

If K2CO3 ____________ g original compound → ____________ g chloride

5.Calculate the theoretical value of Q for all 4 compounds

6.What was the student’s observed value of Q? ( I got 1.378 since this is calculated by original mass divided by final mass)

7.Which compound did the student have as their unknown?

Let EE and FF be events of an experiment. Select all of the sentences below that are correct. Marks will be deducted for selecting options that are incorrect.

Select one or more:

a. If EE and FF are mutually exclusive then they must also be independent.

b. If EE and FF are independent then Pr(E∩F)=Pr(E)Pr(F)Pr(E∩F)=Pr(E)Pr(F).

c. If EE and FF are mutually exclusive then EE and FF can't occur at the same time.

d. It is possible for EE and FF to be neither mutually exclusive nor independent.

e. If EE and FF are mutually exclusive then Pr(E∪F)=0Pr(E∪F)=0.

In an experiment involving the breaking strength of a certain type of thread used in personal flotation devices, one batch of thread was subjected to a heat treatment for 60 seconds and another batch was treated for 120 seconds. The breaking strengths (in N) of ten threads in each batch were measured. The results were

60 seconds: 43 52 52 58 49 52 41 52 56 50 120

seconds: 59 55 59 66 62 55 57 66 66 51

Let μX represent the population mean for threads treated for 120 seconds and let μY represent the population mean for threads treated for 60 seconds. Find a 99% confidence interval for the difference μX−μY . Round down the degrees of freedom to the nearest integer and round the answers to three decimal places.

The 99% confidence interval is ( , ).

What Lewis acid is used in the acetylation reaction of ferrocene?

In the experiment of acetylation of ferrocene, what will be the ordering of elution? How will you explain the observed ordering?

A mixture of cis and trans isomers of [Cr(CO)₄(PPh₃)₂] is loaded onto a column and eluted with 10:90 ethyl acetate : petroleum ether solvent mixture. Which isomer will elute first? Why?

What two acetylated products are isolated from the acetylation of ferrocene? Which of the products is the minor product and how will you explain the poor yield of the minor product?

(12pts) An experiment was conducted to examine the effect of age on heart rate when a person is subjected to a specific amount of exercise. Ten male subjects were randomly selected from four age groups: 10-19, 20-39, 40-59, and 60-69. Each subject walked on a treadmill at a fixed grade for a period of 12 minutes, and the increase in heart rate, the difference before and after exercise, was recorded (in beats per minute). Answer the questions based on the printout.

(2pts) Write the null and alternative hypotheses for this test.

(2pts) Give the test statistic and P-value for this problem.

(4pts) Write your conclusions for this test in terms of the story.

(4pts) The output for the Bonferroni Multiple Comparisons procedure is given below. If it is appropriate to use that at this point, explain why and give the conclusions to the procedure. If it is not appropriate to use Bonferroni at this point, explain why not.

In an experiment, 25.5 g of metal was heated to 98.0°C and then quickly transferred to 150.0 g of water in a calorimeter. The initial temperature of the water was 23.0°C, and the final temperature after the addition of the metal was 32.5°C. Assume the calorimeter behaves ideally and does not absorb or release heat.

1.) What is the value of the specific heat capacity (in J/g•°C) of the metal?

_____ J/g•°C

Suppose that you performed a new glucose experiment with a different set of standards and a different wavelength, where x is concentration is M and y is ∆A.

The ∆A for the unknown is 0.123. Calculate the relative uncertainty on the unknown, i.e., u/c_unk. Use 2 sign figs

A student conducts an experiment boiling water in a 3.96L pot. The Diameter of the base of the pot is 7-3/4” and the height is 5-1/8”.

2 Liters of water @ 23°C takes 17 minutes before it reaches a boil. It has a height in the pot of 2-3/4”. The process took 1 hour and 13 minutes to boil dry. How much energy was required to do this?

In an experiment to study the photoelectric effect, a scientist measures the kinetic energy of ejected electrons as a function of the frequency of radiation hitting a metal surface. She obtains the following plot (Figure 1). The point labeled "?0" corresponds to light with a wavelength of 523 nm.*the image wouldn't attach*

A). What is the value of ?0 in s?1?

B). What is the value of the work function of the metal in units of kJ/mol of ejected electrons?

C). Note that when the frequency of the light is greater than ?0, the plot shows a straight line with a nonzero slope. What is the slope of this line segment? Note that when the frequency of the light is greater than, the plot shows a straight line with a nonzero slope. What is the slope of this line segment?