in an experiment, 15.0 g of ice at -30 celsius is converted into steam with a temperature of 115 celsius. How much energy is required for this process? DHvap= 2260 J/g; DHfus= 334 J/g; cs(ice)= 2.06 J/(g celsius; cs(water)= 4.18 J/(g celsius; cs(steam)= 1.99 J/(g celsius))

In an experiment, a student was asked to measure the desity of an unknown liquid. He was given a small flask, which he found to have a mass of 32.6195 grams when empty. He filled the flask with water at 21.6 (0.997860 g/mL) degrees C and found the full flask to have a mass of 156.8995 grams. The student then emptied and dried the flask and then filled the flask with an unknown liquid. The mass of the flask filled with the unknown liquid was 134.2515 grams. Determine the volume of the flask and density of the unknown liquid.

An experiment was made to measure the mean number of axe strikes that is necessary to cut a tree trunk. A total of 16 identical tree trunks were cut by a randomly chosen person, and the following data (number of axe strikes) was collected: 52, 54, 56, 55, 57, 47, 53, 45, 46, 48, 55, 57, 51, 54, 56, 52. Is there sufficient evidence to conclude that the median number of strikes is 50?

An experiment was made to measure the mean number of axe strikes that is necessary to cut a tree trunk. A total of 16 identical tree trunks were cut by a randomly chosen person, and the following data (number of axe strikes) was collected: 52, 54, 56, 55, 57, 47, 53, 45, 46, 48, 55, 57, 51, 54, 56, 52. Is there sufficient evidence to conclude that the median number of strikes is 50?

An experiment was conducted to test the effect of a new drug on a viral infection. After the infection was induced in 100 mice, the mice were randomly split into two groups of 50. The first group, the control group, received no treatment for the infection, and the second group received the drug. After a 30-day period, the proportions of survivors, p̂1 and p̂2, in the two groups were found to be 0.36 and 0.64, respectively.

(a) Is there sufficient evidence to indicate that the drug is effective in treating the viral infection? Use α = 0.05.

(b) Find the test statistic and rejection region. (Round your answers to two decimal places. If the test is one-tailed, enter NONE for the unused region.)

(c) Use a 95% confidence interval to estimate the actual difference (p₁ − p₂) in the survival rates for the treated versus the control groups. (Round your answers to two decimal places.)

The goal of this experiment is to prepare an aqueous solution of sodium hydroxide and determine its concentration by titrating it with a solution containing a precise mass of potassium hydrogen phthalate KHC8H4O4 (abbreviated KHP). The reaction formula is: NaOH(aq) + C8H5KO4(aq) → NaC8H4KO4(aq) + H2O(l). This indicates that the ration of NaOH to KHP is 1:1 which means that 1mol KHP is equal to 1 mol NaOH. ​

A. Calculate the relative average deviation (RAD) for your standardized solution (in parts per

thousands).

B. Does a RAD measure accuracy or precision? Explain.

C. What goal was accomplished by standardizing these solutions?

D. How does the precision from this week effect next week’s results?

An experiment was conducted in laying hens to examine the in
uence of several hormones on biliary secretionsin laying hens. White leghorn hens were surgically
tted with cannulas for collecting secretions and a jugular cannula for continuous
infusion of the hormones under investigation. One trial per day was conducted on
each hen, as long as her implanted cannulas remained functional. Each trial began
with an infusion of saline for 20mins, after which biliary secretions were collected
and new vials attached to the cannulas. Infusion of a hormone was then begun and
continued for 40mins. Measurement of secretion levels was then repeated. The le
\A2Q3.txt" contains data for two di erent hormones. The variables \Bilsecpr" and
\Bilsecpt" contain the pre- and post- hormone treatment measurements. Are there
significant changes in secretion rates with any of the hormones? Compare also the
changes in secretion rate between the two hormones and comment on your findings.

What type of test to use, assumptions and hypothesis with the selected test?

An experiment on tethered mine motions is to be conducted in fresh water in a wave tank. The mine is a sphere of 5cm diameter made of polystyrene (weight assumed negligible). The anchoring block is a lead cube of side length 5cm. The specific gravity of lead is 14.0. If the mine is joined to the lead cube by a light chord such that it floats completely submerged just below the free surface, determine:

a) the tension in the chord

b) the reaction force between the lead cube and the bottom of the tank.

The purpose of this experiment was to determine the equilibrium constant of the reaction between iron (III) chloride (FeCl3) and potassium thiocyanate (KSCN) through the use of spectrophotometry.

Part A: Producing the calibration curve

Part B: FInding the equilibrium concentraions

Why were FeCl3 and HCl added to the blank solutions? Why not just use distilled water for the blanks? Why would you use two different blank solutions for parts A and B?

The data for an Enzyme with a Kcat is 5,000m-1. This experiment was performed by adding a given amount of substrate of 100 micrograms of enzyme in buffer solution. What is the molecular weight of the enzyme?