Alex

I need a little help calculating the grade I would need on my final to get a 90% for the class.

Here's the grading breakdown:

80% of the final grade is from 5 tests (4 regular tests and 1 final which is worth TWICE as much as a regular test)

20% of the final grade is from lab.

Here are my scores:

test 1- 80%

test 2- 70%

test 3- 92%

test 4- 90%

test 5 (final)- ??

*tests 1-4 are out of 100 possible points and the final is out of 200 points*

Lab grade: 98% average

So, what is the grade I need to get on my final to get a 90%?

thanks

0.213 g of an unknown monoprotic acid required 34.55 mL of 0.1007 M NaOH solution to reach a pink end point with phenolphthalein indicator.

a) How much acid would be required to neutralize 25.00 mL of the same NaOH solution?

---Would this just be the ratio .213/34.55 = x/25 where x= .154 g

b) What is the molar mass of the acid?

c) What would the molar mass of the acid in the above question be if it were diprotic?

---I would just add 1.008 grams to b) to get this value, correct?

10 points for best answer.

Determine the volume of sulfuric acid (in mL) needed to prepare 37.4 g of Aluminum Sulfate by the reaction:

2 Al + 3 H2SO4 --> Al2(SO4)3 + 3 H2

The sulfuric acid solution, whose density is 1.104 g/mol containts 15% H2SO4 by mass.

I get 4.38 mL, but that's wrong...

1) The reaction of which acid with water is product-favored?

a. nitric acid

b. chloric acid

c. nitrous acid

d. chlorous acid

e. phosporous acid

2) Which of the following is the strongest acid in aqueous solution?

a. H3PO4

b. H3AsO4

c. H3PO3

d. H3AsO3

e. H3SbO4

1. Which of the following solutes, dissolved in 1kg of water would be expected to provide the fewest particles and to FREEZE at the HIGHEST temperature?

a. HClO4

b. HClO3

c. HClO2

d. HClO

e. HCl

(all at constant Molarity)

2. The ionization constant of water at a temperature above 25 C is 2.0 x 10^-14. What is the pH of pure water at this temperature?

2 H2O --> H3O+ + OH-

a. 13.77

b. 6.85

c. 7.00

d. 7.85

e. 5.65

3. What is the hydromium ion concentration of a .0041 M Ba(OH)2 solution?

a. 1.0 x 10^-12

b. 8.2 x 10^-3

c. 4.1 x 10^-3

d. 2.4 x 10^-12

e. 1.0 x 10^-7

1) The reaction of which acid with water is product-favored?

a. nitric acid

b. chloric acid

c. nitrous acid

d. chlorous acid

e. phosporous acid

2) Which of the following is the strongest acid in aqueous solution?

a. H3PO4

b. H3AsO4

c. H3PO3

d. H3AsO3

e. H3SbO4

1)

A sample of ammonia gas was allowed to come to equilibrium at 400K.

2 NH3 (g) --> N2 (g) + 3 H2 (g).

At equilibrium, the concentration of H2 is .0270 M, the concentration of N2 is .00901 M, and the concentration of NH3 is .0920 M. What is Kp (equilibrium constant for pressure) for this equilibrium?

*R=.0821*

How many grams of pure H2SO4 can be obtained from 250 grams of iron ore if the ore is 82% FeS2? The reactions involved are given below:

4FeS2 + 11 O2 --> 2 Fe2O3 + 8 SO2 (95% efficient)

2SO2 + O2 --> 2SO3 (90% efficient)

SO3 + H2O --> H2SO4 (90% efficient)

1. In the reaction 2H2O2 --> 2H2O + O2, the initial concentration of H2O2 is 0.555 M and 20.4 seconds later, the concentration of H2O2 is 0.306 M. What is the initial rate of the reaction?

a) 0.0122 M/s

b) -0.00610 M/s

c) -0.0122 M/s

d) 0.00610 M/s

e) 0.0150 M/s

2. The hypochlorite ion oxidizes the iodide ion in aqueous solution as represented by the following equation: OCl- + I- --> OI- + Cl-. The rate law is Rate=k *[I-]*[OCl-]/[OH-]. If time is measured in seconds and concentration (denoted by []) is measured in moles per liter, what are the units for K?

A compound containing carbon and nitrogen has a composition of 46.16% carbon and 53.84% nitrogen by mass. A solution prepared by dissolving 3.388 g of this compound in 50.00 g of carbon tetrachloride (CCl4) produces a solution that boils at 83.27 degrees C. What is the molecular formula of the compound? (Boiling Point Constant for CCl4 is 5.03 C/m, and pure CCl4 has a freezing point of 76.72 degrees C.

a) CN

b) C2N2

c) C3N3

1. A 12.0% sucrose solution by mass has a density of 1.05g/cm^3. What mass of sucrose is present in a 25.0 mL sample?

2. A sulfuric acid solution that is 65.0% H2SO4 by mass has a density of 1.55 g/mL at 20 degrees C. What is the molality of sulfuric acid in the solution?

For the following reaction, 4.66 grams of calcium hydroxide are mixed with excess sulfuric acid. The reaction yields 7.72 grams of calcium sulfate.

sulfuric acid (aq) + calcium hydroxide (s) = calcium sulfate (s) + water (l)

What is the theoretical yield of calcium sulfate in grams ?

What is the percent yield of calcium sulfate ?

For the following reaction, 5.98 grams of chlorine gas are mixed with excess phosphorus (P4). The reaction yields 6.81 grams of phosphorus trichloride.

phosphorus (P4) (s) + chlorine (g) phosphorus trichloride (l)

What is the theoretical yield of phosphorus trichloride in grams?

What is the percent yield for this reaction ? %

For the following reaction, 3.23 grams of oxygen gas are mixed with excess benzene (C6H6). The reaction yields 2.96 grams of carbon monoxide.

benzene (C6H6) (l) + oxygen (g) carbon monoxide (g) + water (g)

What is the theoretical yield of carbon monoxide in grams ?

What is the percent yield of carbon monoxide ?

What are the type I and type II errors of each?

assume that the given hypotheses are true.

a) The percentage of Americans who believe that life exists only on Earth is equal to 20%.

b) The percentage of households with at least two cell phones is less than 60%.

For each question, write the Type I and Type II errors that corresepond to the given hypothesis:

a) The percentage of Americans who believe that life exists only on Earth is equal to 20%.

b) The percentage of households with at least two cell phones is less than 60%.

If 22 percent of all sodas dispensed by a vending machine overflow their cups, then :

a) What is the probability that exactly five out of the ten will overflow?

b) What is the probability that at most two of the next twn will overflow?

c) Now suppose their are 100 sodas in the machine. What is the expected number (the mean) of these 100 dispensed sodas that will overflow their cups?

d) Again, suppose their are 100 sodas in the machine. What is the standard deviation of these 100 dispensed sodas that will overflow their cups?

1. Suppose some standardized tests given to high school juniors have a mean of 500 and a standard deciation of 50. The test scores are normally distributed.

What is the shape,mean,and standard deviation of the sampling distribution of x bar of a sample of n=36 randomly selected juniors?

Please explain the process because I want to see how you figured it out, thanks!

The weight of ripe pumpkins grown at Mr. Mike's farm are normally distributed with a mean of 8 pounds and a standard deviation of 2 pounds. The Interquartile Range (IGR) is Q3-Q1. Find the IQR of Mr. Mike's pumpkins. Make sure to show all of your calculations and explain.

Any help is appreciated.

The weight of ripe pumpkins grown at Mr. Mike's farm are normally distributed with a mean of 8 pounds and a standard deviation of 2 pounds. The Interquartile Range (IGR) is Q3-Q1. Find the IQR of Mr. Mike's pumpkins. Make sure to show all of your calculations and explain.