# Questions Asked onFebruary 20, 2012

1. ## chemistry - crude product

WHAT IS THE CRUDE PRODUCT IN RECRYSTALLIZATION?

2. ## Trigonometry

Simplify #1: cscx(sin^2x+cos^2xtanx)/sinx+cosx = cscx((1)tanx)/sinx+cosx = cscxtanx/sinx+cosx Is the correct answer cscxtanx/sinx+cosx? Simplify #2: sin2x/1+cos2X = ??? I'm stuck on this one. I don't know what I should do. Simplify #3:

3. ## Chemistry

For the following reaction, Kp = 3.5 104 at 1495 K. H2(g) + Br2(g) 2 HBr(g) What is the value of Kp for the following reactions at 1495 K? (a) HBr(g) 1/2 H2(g) + 1/2 Br2(g) (b) 2 HBr(g) H2(g) + Br2(g) (c) 1/2 H2(g) + 1/2 Br2(g) HBr(g)

4. ## Chemistry

The equilibrium constant Kp for the reaction below at 700°C is 0.76 atm. CCl4(g) --> C(s) + 2 Cl2(g) Determine the initial pressure of carbon tetrachloride that will produce a total equilibrium pressure of 1.20 atm at 700°C

5. ## Geometry Are these two triangles similar? Thanks!

Are these two triangles similar? How do you know? There are two triangles HMG and JMK They are connected at the top point at M H is on the bottom left, G is on the bottom right, and M is at the top for triangle HMG For triangle JMK J is on the bottom right

6. ## geometry

A 24 foot ladder forms a 76 degree angle with the ground. The top of the ladder rests against the building. To the nearest inch how high up the building does the ladder reach?

7. ## English

It must be nice," she said. "It must be very nice. I wish women could do such things." "It ain't the right kind of a life for a woman. Her upper lip raised a little, showing her teeth. "How do you know? How can you tell?" she said. "I don't know, ma'am,"

8. ## calculus

the point (1,9) lies on the graph of an equation y=f(x) for which dy/dx=4x(sqrt(y)) where x is greater than or equal to 0 and y is greater than or equal to 0 a)6 b)4 c)2 d)sqrt(2) e)0

9. ## Chemistry

At 2200°C, K = 0.050 for the following reaction. N2(g) + O2(g) 2 NO(g) What is the partial pressure of NO in equilibrium with N2 and O2 that were placed in a flask at initial pressures of 0.81 atm and 0.20 atm, respectively

10. ## Chemistry

The equilibrium constant Kp for the reaction below at 700°C is 0.76 atm. CCl4(g) C(s) + 2 Cl2(g) Determine the initial pressure of carbon tetrachloride that will produce a total equilibrium pressure of 1.20 atm at 700°C

11. ## Chemistry

How much HCO2H is obtained by reacting 3.0g of FeS, 1.60g H2S, and 1.60g CO2 if the reaction results in a 47.0% yield? I know that I need to the molar mass of each which FeS-3.2/87.9=0.036 H2S-1.6/34.1=0.047 CO2-1.6/44.0=0.363 I just don't know other step

12. ## managerial economics

Exercise 1 The marketing manager has estimated the company’s demand curve with the equation P=3000 – 40Q. To develop a deeper understanding of pricing and quantity to be produced, complete the following analyses: 1. Draw the demand curve (use a range

A model for the length of daylight (in hours) in Philadelphia on the t th day of the year is L(t)= 12+2.8 sin[2pi/365(t-80)] Use this model to compare how the number of hours of daylight is increasing in Philadelphia on March 21 and May 21. (Assume there

14. ## Physical Science

How do you write the chemical equation for neutralization of nitric acid, HNO3, with magnesium hydroxide, Mg (OH)2, first with spectator ions and then without spectator ions?

15. ## Chemistry

Consider the reaction below. 3 O2(g) --> 2 O3(g) At 175°C and a pressure of 128 torr, an equilibrium mixture of O2 and O3 has a density of 0.168 g/L. Calculate the Kp for the above reaction of 175°C

16. ## history

2. In what ways can the progressive educational movement be used to exemplify issues that are important to historians of other social and political movements? Was the progressive educational movement a "typical" social or political movement?

2L of 6M HCl

18. ## physics

A water-skier lets go of the tow rope upon leaving the end of a jump ramp at a speed of v1 = 14.7 m/s. the skier has a speed of v2 = 12.7 m/s at the highest point of the jump. Ignoring air resistance, determine the skier's height H above the top of the

19. ## chemistry

How many iron atoms are in 0.32 mol of Fe2O3

20. ## chemistry

While trace impurities of iron and chromium in natural corundum form the gemstones ruby and sapphire, they are basically a binary compound of aluminum and oxygen, with 52.9% Al. Find the empirical formula and give the chemical name for corundum. the answer

21. ## CHEMISTRY

Find the amount of CuSO4.5H2O needed to prepare 500 mL of 0.25 M solution.

22. ## Chemistry

Ba(NO3)2 is added (BaCrO4 (s) is less soluble than BaCr2O7 (S)) provide an explanation Thank You

23. ## math finite

Assume that there are 7 different issues of Newsweek, 8 different issues of Time, and 4 different issues of Sports Illustrated, including the December 1st issue, on the rack. You choose 4 of them at random. (1) What is the probability that you choose 2

24. ## earth

A satellite 200 miles above the earth is orbiting the earth once every 6 hours. How long, in hours, does it take the satellite to travel 8,400 miles? (Assume the radius of the earth is 4,000 miles.) Give your answer both as an exact value and an

25. ## Chemistry

So, they give me a word equation, where I am suppose to try and create a balanced equation for it. Ammonium phosphate and barium hydroxide react to form ammonium hydroxide and barium phosphate. 2(NH4)3PO4 + 3BaOH2 → 6NH4OH + Ba3(PO4)2 [I was thinking

26. ## Physics

A penny is placed at the outer edge of a disk (radius = 0.159 m) that rotates about an axis perpendicular to the plane of the disk at its center. The period of the rotation is 1.50 s. Find the minimum coefficient of friction necessary to allow the penny to

The decomposition of an aldehyde solution in carbon tetrachloride is a first order reaction with a rate constant of 1.20 x 10-3 min-l. If we start with [aldehyde] = 0.0500 molar, what will the concentration be 150 minutes later? 1.20e-3(150) = 0.18

28. ## Chemistry

For the reaction below at a certain temperature, it is found that the equilibrium concentrations in a 5.00 L rigid container are [H2] = 0.0500 M, [F2] = 0.0100 M, and [HF] = 0.400 M. If 0.340 mol of F2 is added to this equilibrium mixture, calculate the

29. ## science

Consider the following reaction: CH3X + Y --> CH3Y + X At 25ºC, the following two experiments were run, yielding the following data: Experiment 1: [Y]0 = 3.0 M [CH3X] Time (hr) 7.08 x 10-3 M 1.0 4.52 x 10-3 M 1.5 2.23 x 10-3 M 2.3 4.76 x 10-4 M 4.0 8.44 x

30. ## Chemistry

For the reaction given below, the frequency factor A is 8.7 multiplied by 1012 s-1 and the activation energy is 63 kJ/mol. NO(g) + O3(g) NO2(g) + O2(g) What is the rate constant for the reaction at 55°C?

31. ## Math

An electronic store receives a shipment of 30 graphing calculators, including 6 that are defective. Four of these calculators are selected to be sent to a local high school. How many selections can be made? How many of this selections will contain two

32. ## calculus

The average (mean) value of (1/x) over the interval 1

33. ## Math

A sensor light installed on the edge of a home can detect motion for a distance of 50ft. in front and with a range of motion of 192degree. Over what area will the sensor detect motion and become illuminated?

34. ## PHYSICS HEELLPPP!!

Many people mistakenly believe that the astronauts who orbit the Earth are "above gravity." Calculate g for space shuttle territory, 225 kilometers above the Earth's surface (dashed line in sketch). Earth's mass is 6 1024 kg, and its radius is 6.38 106 m

35. ## math - probability

Assume that there are 7 different issues of Newsweek, 8 different issues of Time, and 4 different issues of Sports Illustrated, including the December 1st issue, on the rack. You choose 4 of them at random. (1) What is the probability that you choose 2

36. ## physics

A 820-{\rm kg} sports car collides into the rear end of a 2700-{\rm kg} SUV stopped at a red light. The bumpers lock, the brakes are locked, and the two cars skid forward 3.0 {\rm m} before stopping. The police officer, estimating the coefficient of

37. ## Psychological Statistics

A researcher predicts that watching a film on institutionalization will change students’ attitudes about chronically mentally ill patients. The researcher randomly selects a class of 36 students, shows them the film, and gives them a questionnaire about

38. ## English-metaphors

Is this quote a metaphor? "That's a bright direction, there's a glowing there." In context it seems like a metaphor since the direction she is looking in is not actually bright or glowing. there was a lot of text for the question but I thought it e too

39. ## trig

The minute hand of a clock is 6 inches long. What distance does its tip move in 16 minutes?

40. ## Chemistry

Consider the reaction below. 3 O2(g) --> 2 O3(g) At 175°C and a pressure of 128 torr, an equilibrium mixture of O2 and O3 has a density of 0.168 g/L. Calculate the Kp for the above reaction of 175°C

49. ## math

Assume that the coin is flipped 10 times. What is the probability that both heads and tails occur?

50. ## physics

A roller coaster moves 200 ft horizontally and then rises 135 ft at an angle of 30 degrees above the horizontal. Next, it travels 135 ft at an angle of 40 degrees below the horizontal. Find the roller coasters displacement from its starting point to the

51. ## physics

The speed of sound in water is 1498 m/s. A sonar signal is sent straight down from a ship at a point just below the water surface, and 1.62 s later, the reflected signal is detected. How deep is the water?

52. ## Physics

An upward force of 35 N is applied via a string to lift a ball with a mass of 2.1 kg. (a) What is the net force acting upon the ball? (b) What is the acceleration of the ball?

53. ## math

Darius uses the shadow method to estimate the height of a flagpole. He finds that a 5 foot stick casts a 4 foot shadow. At the same time he finds that the flagpole casts a 20 foot shadow. Make sketch. Use Darius's measurements to estimate the height of the

54. ## phys4

A 31.5-kg child swings on a rope with a length of 6.26 m that is hanging from a tree. At the bottom of the swing, the child is moving at a speed of 4.2 m/s. What is the tension in the rope?

55. ## GEOMETRY

If EF=3x-10, FG=2x-15 and EG=20, find the value of x, EF and FG.

56. ## chem 111 lab

if a student used 12.45mL of their NaOH solution to neutralize 10.00mL of a 0.543 KHP solution, then what is the concentration of the student's NaOH solution?

84. ## Chemistry

1)For the reaction, A = B + C, the rate law is k(A). If it takes 80.0 seconds for 70.0% of a 10.0 gram sample of A to be transformed into products, what is the value of the rate constant? I was going to do 80/10 = 8 and then 8 times .70 but im not sure

85. ## chemistry- solubility

hydrocarbons nhexane, cyclohexane, and toluene are are insoluable in H2O (i assume because the hydrocarbons are non polar and water is polar) but why are these three hydrocarbons soluable in CH2Cl2?

86. ## English

I urgently need you to check this summary I wrote on "fiction". I'm sending it into two separate posts. Thank you very much, writeacher!! 1) The setting is the time and place in which the action of a book happens. The setting can reveal a great deal about

87. ## Chemistry

At a particular temperature, K = 2.0 10-6 mol/L for the following reaction. 2 CO2(g) 2 CO(g) + O2(g) If 1.8 mol CO2 is initially placed into a 5.9-L vessel, calculate the equilibrium concentrations of all species.

88. ## Physics

A penny is placed at the outer edge of a disk (radius = 0.159 m) that rotates about an axis perpendicular to the plane of the disk at its center. The period of the rotation is 1.50 s. Find the minimum coefficient of friction necessary to allow the penny to

89. ## statistics

Among coffee drinkers, men drink a mean of 2.8 cups per day with a standard deviation of 0.5 cups. Assume the number of drinking per day follows a normal distribution. What proportion drink 3 cups per day or more?

90. ## chemistry

While trace impurities of iron and chromium in natural corundum form the gemstones ruby and sapphire, they are basically a binary compound of aluminum and oxygen, with 52.9% Al. Find the empirical formula and give the chemical name for corundum. i really

91. ## math

the mean teaching hours for a full time faculty at a university is 8 hours per week what does this tell you about the typical teaching hours for a full time faculty at that university

92. ## Social studies

I really need help on this, please! I've been reading my book for an hour and found no answer. Ok so here it is: Sumer lacked resources such as ... I have to list three resources that Sumer lacked. Please help. Thanks !

93. ## chemistry

In a lab experiment I added Br2 to hydrocarbons cyclohexane, cyclohexene, and toluene. A loss of color would indicate a reaction took place. Only the cyclohexene lost color and turned clear. I guess this means that the Br2 broke the cyclohexenes double

94. ## English

Thank you very much. Here is a summary I need to prepare for tomorrow. I also need to rephrase the last sentence. Thank you very much, Writeacher! 1) Though Craig Jones is an office worker, he is also a talented singer who dreams of becoming a star. 2) He

95. ## math

according to a survey of 800 students, about 3/4 of them chose pizza as their favorite food. Of those who chose pizza, 1/2 liked pepperoni topping the best. How many students liked pepperoni topping the best?

96. ## micro econ

Suppose that through laziness and/or sheer stupidity, Densa Inc. always falls 10 percent short of producing the profit-maximizing output. Would higher product price lead to greater output? Does this result suggest why economists are not overly concerened

97. ## Math 12

Simplify #1: cscx(sin^2x+cos^2xtanx)/sinx+cosx = cscx((1)tanx)/sinx+cosx = cscxtanx/sinx+cosx Is the correct answer cscxtanx/sinx+cosx? Simplify #2: sin2x/1+cos2X = ??? I'm stuck on this one. I don't know what I should do. Simplify #3:

98. ## calculus

A 33 by 33 square piece of cardboard is to be made into a box by cutting out equal square corners from each side of the square. What size corners should be cut out so that the volume of the box is maximized?

328. ## algebra

a bump on a dvd needs to be between 0.45 and 0.55 micron wide and between 0.95 and 0.99 micron high write two absolute value inequalities describing the width (x) and height (y) of the bump graph each inequality on separate number lines

329. ## algebra

A DVD player's laser reader helps to "read" the information on the DVD. A particular laser reader measures 0.56 micron thick. Does this fall with the required standards if a company uses |t - 0.03| less than or equal to 0.525 for determining the part to be

330. ## Physics

Isaac pushes rock, of a mass of 20kg, if from a cliff and it falls into the lake below. The cliff was 3m above the water. (Assume no air resistance) a. How much time did it take the rock to hit the water? b. What was its velocity when it was half of the

331. ## science

i need to find a website that has a picture of hafnium lamp filaments

332. ## Pre-Calculus/Trivia

csc(theta)= 1/x sec(theta)= 1/ sqrt(1-x^2) cot(theta)= sqrt(1-x^2)/x What are these equations used for in real life matters or in regards to calculus? Can't seem to find the answer anywhere :/

333. ## Human resource

Can someone explain me this question: explain how and to what extent THE CONCEPT OF PEOPLE HAS CHANGED OVERTIME ,HENCE,HIGHLIGHTING THE EVOLUTION AND GIVING PRACTICAL EXAMPLES TO ILLUSTRATE YOUR ANSWER. am new to this module and can someone pls explain

334. ## Math

A bicyclist travels 20 miles per hour. How long would it take the cyclist to finish a 120 mile race?

335. ## English

Could you check if the following instructions are correct? Thank you. 1) It takes me ten minutes to go to school by motorbike 2)Complete the sentences with the correct form of the Present simple or the Present continuous 3) Complete Mary’s story with the

336. ## Ground School: Regulations

I am working on my private pilot license and these regulation things, HOW do you learn all of them?????????

337. ## math

it is 6;45am how many hours and minutes until 10;38pm

338. ## Math

A person travels 32 meters,turns right & travels 34 more meters. It took 3 minutes. What is her speed?

339. ## Algebra

How many hours are in x weeks? X/168 24x/7 7x/24 168x

340. ## stats

The sponosor of a local soccer tournament is responsible for writting an article for the local paper announcing the 1st, 2nd, 3rd place winners.If 10 teamsare invited to the tournament, ans th sponsor wanted to get the article written in adance so it can