1. Chemistry

A buffer consists of 0.16 M KHCO3 and 0.39 M K2CO3. Carbonic acid is a diprotic acid with Ka1 = 4.5 10-7 and Ka2 = 4.7 10-11. (a) Which Ka value is more important to this buffer? Ka1 Ka2 I don't understand this one at all. How do I determine which Ka value

2. Chemistry

A beaker of nitric acid is neutralized with calcium hydroxide. Write a balanced molecular equation and a net ionic equation for his reaction

3. Algebra

Suppose a population of 160 crickets doubles in size every month. The function gives the population after x months. How many crickets will there be after 2 years? (1 point)2,684,354,560 crickets 640 crickets 7,680 crickets 655,360 crickets

4. Analytical Chemistry

How many milliliters of 0.0560 M EDTA are required to react with 50.0 mL of 0.0170 M Cu^2+? With 50 mL of 0.0170 M Sc^3+? My work so far: (50mL)(0.0170mmol/mL)= 0.85 mmol Cu^2+ I'm not sure how to do the rest. Please help.

5. physics

An ocean wave travels 17.1 m in 6.7 s. The distance between the two nearest wave crests is 5.1 m. What is the frequency of the wave? Answer in units of H

6. Physics

If you walk 2 km from your house to a store then back home, whats your displacement? (Displacement is the difference between 1st position and final position)

62. physic

a 2500 car enters curve with a radius of 45 m .if the car is moving at speed of 35 m/s.what is the centripetal force that maintains the car s circular motion the curve ?

63. Social Studies

How did the immigrants who came to the United States between 1820 and 1860 change the character of the country?

64. Chemistry

A 1.44-g sample of an unknown pure gas occupies a volume of 0.336 L at a pressure of 1.00 atm and a temperature of 100.0 degrees Celsius. What is the unknown gas?

65. math

how munch sand in cubic feet for a sandbox 6 inches high 3 feet wide 3 feet long

66. corporate finance

1. Which of the following is NOT correct for a firm with seasonal sales and customers who all pay promptly at the end of 30 days? a. DSO will vary from month to month. b. The quarterly uncollected balances schedule will be the same in each quarter. c. The

67. Chemistry

Calculate the mass percent composition of carbon in each the following carbon compounds. C2H2 C3H6 C2H6 C2H6O

68. Stat

1. For the following scores, X Y 1 6 4 1 1 4 1 3 3 1 Sketch a scatter plot and estimate the value of the Pearson correlation. b. Compute the Pearson correlation 2. For the following set of scores, X Y 6 4 3 1 5 0 6 7 4 2 6 4 a. Compute the Pearson

69. plzzzzzzz help me out.

a beam of light consisting of two wavelengths 800nm and 600 nm is used to obtain the interference pattern in youngs double slit expt on a screen placed 1.4m away.if two slits are separated by 0.28mm,calculate the least distance from the central bright

70. math

John drives to work each morning and the trip takes an average of µ = 38 minutes. The distribution of driving times is approximately normal with a standard deviation of σ = 5 minutes. For a randomly selected morning, what is the probability that John’s

71. chemistry

the equilibrium constant of the decomposition of NOCL is 1.6*10^-5. calculatethe concentration of all species at equilibrium if initially 3.52 mol of NOCL is placed in a 5.00 L container

72. chemistry

Calculate the molar concentration of OH− ions in an 1.79 M solution of hypobromite ion (BrO−; Kb = 4.0 10-6).

73. statistics

Is "42% of the people in New York City have 0+ blood" desriptive or inferential?

74. Finite, Math, Probability

Assume that there are 18 board members: 12 females, and 6 males including Larry. There are 3 tasks to be assigned. Note that assigning the same people different tasks constitutes a different assignment. Find the probability that both males and females are

75. English

Read the following sentence: Moses was a hebrew prophet and led his people out of captivity. What is the simple subject of this sentence? A: Hebrew prophet B: people C: Captivity D: Moses Answer A ?

76. maths

A Plank of Wood 6 m Long is cut in the ratio 1:5. find the length of the Longer Piece in centimetres.

77. Physics: Aluminum Block

A 1.65-kg aluminum block and a 6.85-kg copper block are connected by a light string over a frictionless pulley. The two blocks are allowed to move on a fixed steel block wedge (of angle è = 31.0°) as shown in the figure. Making use of the table below,

78. algebra

A ball is thrown upward with an initial velocity of 14 meters per second from a cliff that is high. The height of the ball is given by the quadratic equation H = 49t^2 + 14t +60 where h is in meters and t is the time in seconds since the ball was thrown.

79. Physics

A basketball is thrown from the ground into the air at an angle of 30 degrees to the horizontal. If this object reaches a maximum height of 5.75m, at what velocity was it thrown? How am i suppose to do this question if no velocity is given? I need help. I

80. World History

What is the significance of James Buchanan? My answer: James Buchanan is significant because he won the election of 1856 and became the president of the United States.

81. math

Lamar deposits 5000 into an account that pays interest at 4% per year. How much interest wilk he be paid in the first 3 years

82. statistics

*Give all probabilities to four decimal places. Bowl #1 contains 4 grape candies, 5 lemon candies, 6 cherry candies and 5 raspberry candies. Bowl #2 contains 8 grape candies, 5 lemon candies, 4 cherry candies and 3 raspberry candies. (c) What is the

83. Literature

Douglass includes a lot of maxims in his Narrative. What is the effect of these? They make his autobiography less believable because some of them are not true. He reveals many of the values of the people during the time in which he lived. They demonstrate

84. World History

What is the significance of John C. Fremont? My answer: John C. Fremont is significant because he became a national hero for his explorations in the West, which earned him the nickname the "Pathfinder?"

85. Math

Find the missing number in this pair of equivalent ratios. _:12 : 36 and 8 : 4 : 12

86. algebra

if lamar has scored 99,71,58 and 73 on his previous four tests, what score does he need on his next test so that his average is 79?

87. physics

A boy coasts down a hill on a sled, reaching a level surface at the bottom with a speed of 6.2 m/s. If the coefficient of friction between the sled's runners and snow is 0.060 and the boy and sled together weigh 480 N, how far does the sled travel on the

88. Geometry

How many ordered triples (a, b, c) of positive integers are there which satisfy the equation a + b + c = 10 ?

89. English

1. Wilma found a love for running. 2. Wilma found love for running. (Which one is correct?) 3. Wilma tried hard to be able to walk again. (What is the part of speech of 'to be able to walk again'? Is it the object of 'tried'? Or is it an adverbial phrase

90. college algebra

Given the following quadratic equation, find;? a. the vertex b. the axis of symmetry c. the intercepts d. the domain e. the range f. the interval where the function is increasing, and g. the interval where the function is decreasing h. Graph the function.

91. Algebra

Find the number of integer quadruples (a,b,c,d) with 0\leq a,b,c,d \leq 100, such that a and b are the roots of the quadratic equation x^2-cx+d=0, while c and d are the roots of the quadratic equation x^2-ax+b

92. math

an athlete. an run in 6 miles in 51 minutes. at this rate approximately how far could the runner go in 1.5 hours? A. 0.2 miles B. 8.5 miles C. 10.6 miles D. 12.75 miles

93. Chemistry -need help in solving problem

The solubility of a gas at 7.0 atm of pressure is 0.52 g/L . How many grams of the gas would be disolved per 1.0 L if the pressure increased 40 percent?

94. engineering science N4

Two ships leave port simultaneously. Ship A sails north-west at 30 km/h and ship B sails S 40 degrees W at 30 km/h. Calculate the velocity of ship B relative to the velocity of ship A.

95. Chemistry

How much heat (in Joules) is needed to raise the temperature from -79oC to 57oC for 31.5g of water? I remember my teacher using different temperatures for each equation, can someone show me what that is? thanks.

173. Math

A number line starts with 7 and ends with 9.There are 7 marks in between. The letter A is above the 5th mark. What is the value of A as a fraction

174. math

a race track is a mile around circle which equals 5,280 circumference. To find the diameter (the the width of the center of the circle) do I divide the 5,280 by 2?

175. Math

You have to use 3,500 calories to lose one pound. If you play Dance Dance Revolution you can burn 1,000 calories in an hour. How many hours would you have to play in order to lose one pound? Answer is 35 3500 divided by 1,000=35 please help Ms. Sue i think

Assume a circular orbit. If a planet's distance from it star is multiplied by 25 times, then by how many times is its orbital period T multiplied ?

177. more of the same

The answer to this should be 201.7, but I keep getting off track. 300=70+(375-70) e^ -k*10 230=305 e^-10*k ln 230=ln 305 e^-10*k ln 230= ln 305 -10*k

178. Chemistry

How much heat (kcal)is needed to melt 14 ice cubes? Each cube is at 0c and has a mass of 28grams.

179. Physics

An electric filament can heat 200 cm3 of water from 5°C to 95°C in 6 minutes. If the voltage source is a 12 V battery, how much current does it draw?

180. Algebra

the number of state and federal inmates in millions during year x were x more or less than 2002 can be approximated by the following. N=0.03x -59.02. Determine the year there were 1.1 million inmates.

181. college algebra

given the following polynomial find the zero and multiply of each were the graph touches the x axis number of turning points fx =(x-4)(x^2-25)

182. math

please display graph of 2x=1 (if can be) thanks

183. Geography

what is the names of the three small pyramids in front of the gizzza

184. English

Sigmund Freud coined the term _______,which he applied to people who were extremely self-absorbed. A. Dryad B. suspension of disbelief C. moral D. narcissistic Answer: B?

185. help with physics

A gold wire and a silver wire have the same dimensions. At what temperature will the silver wire have the same resistance that the gold wire has at 20°C?

186. algebra

A line with a slope of -2 passes through the point (1, 7). What is the closest point on the line above (1, 7) which has whole number coordinates?

187. Algebra

The difference of the cubes of two consecutive odd positive integers is 400 more than the sum of their squares. Find the sum of the two integers.

what is the net ionic equation for the reaction between a strong acid and a strong base? what does it mean by this question?/ (: thanks.

189. sciences

A solution contains 0.0180 M HNO3, 0.0268 M HI, and 0.250 M formic acid, HCOOH. What is the pH?

190. Calculus

Determine if the series converges or diverges. Sum (n=1, infinity) (2*4*6...2n)/n! My main problem is I have no idea what to do with the numerator.

191. Math

A carton of Girl Scout cookies weighs 15 Lb. Each carton contains 36 boxes of cookies. How many boxes of cookies would 43 cartons contain?

192. Psychology

How could my wife and I find out whether the South Beach Diet works for us? Write the methods section for an experiment.

193. org. chem

Give IUPAC name of the products of the dehydration of this alcohol? 2-ethyl cylcopentanol

194. Physics

Develop a model for the effective gas mileage (call it E) as a function of speed (S) for a ¡°typical¡± car (you should be able to find the necessary information to develop this model for your own car). This model should be valid for 55 ¡Ü S ¡Ü75

195. math

if 2 socks are chosen at random,what is the probality of getting first a black sock and then a blue sock?

1/4 /5=

197. psychology

What implications do the results of an experiment have for subjects that were not observed in the experiment?

198. algebra

a certain mountain has an elevation of 19523 feet. in 1922, the glacier on this peak covered 5 acres. by 2001 this glacier had melted to only 1 acre.

199. GEOmetry

How many 7 digit positive integers are there such that the product of the individual digits of each number is equal to 10000?

200. Algebra

The difference of the cubes of two consecutive odd positive integers is 400 more than the sum of their squares. Find the sum of the two integers.

201. Algebra

Alan and Bob are playing with numbers. Starting with the number n=1 they take turns performing arithmetic manipulations with n. Alan goes first and always multiplies n by 3. Bob adds 1 or 2 to the number n, depending on a coin toss. A number is called

202. English

The assignment is to write a CAUSE paper on an addiction. There is to be three topic sentences with support, a thesis, an introduction and a conclusion. I obviously have left of my sources, and need to insert them. I would really appreciate some feedback

203. Geometry

ABC is a right triangle with AB = 2, BC = 8\sqrt{3} and AC = 14. What is the value of \sec \angle BAC?

204. life orientation

what,according to the basic conditions of employment act applies with regard to the contraventions?

205. TRIGONOMETRY HELP

Prove that: (tan²Θ)x(sin²Θ) = (tan²Θ)-(sin²Θ) show work

206. Algebra

Find the number of integer quadruples (a,b,c,d) with 0\leq a,b,c,d \leq 100, such that a and b are the roots of the quadratic equation x^2-cx+d=0, while c and d are the roots of the quadratic equation x^2-ax+b.

207. Algebra

A mountain has an elevation or 19,389 feetin 1918, the glacier at the peak covered 4 acres, by 2003 this glacier had melted to 1 acre. What was the yearly rate of change. What is the equation that gives the acreage t years after 1918

208. geometry!

Given a 100 by 100 square grid, what is the most number of 1 by 51 rectangles that we can cut out of it?

209. College Algebra

A calculator company produces a scientific calculator and a graphing calculator. Long-term projections indicate an expected demand of at least 100 scientific and 80 graphing calculators each day. Because of limitations on production capacity, no more than

210. math linear alegba

Find the distance from the point (1, 1, 1) to the line given as the intersection of planes x+2y− 2z = 5 and 6x − 3y + 2z = 8.

211. MATH

FIND A AREA OF SQUARE ROOM WHOSE SIDE IS 6CM. THE FLOOR OF ROOM IS TO BE TILLED WITH SQUARE TILES HAVING A SIDE OF 60CM.FIND THE NO.OF TILES REQUIRED

212. Analytical Chemistry

How many milliliters of 0.202 M KOH should be added to 500.0 mL of 0.0233 M tartaric acid (C4H6O6; FW 150.087) to adjust the pH to 2.75? Ka1 = 1.0 x 10-13 and Ka2 = 4.6 x10-5. For this one, the Ka1 seems sort of off. The pka would be 13 which doesn't make

213. Science

How do i obtain the vapor pressure of Molten syrup?

214. collegemath

How high is a wall that cast A 7ft shadow at the same time a 5ft flag pole casts a 5ft shadow

215. Calculus

Determine convergence of divergence. If convergent, find the sum. Sum (infinity, n = 0) (e/pi)^n

216. Math

A fisherman has estimated that it takes 6minutes to paint each square foot of the hull of his boat. How much time should the fisherman allow for the painting of the hull, if the hull were composed of two sides, each 31.5 feet by 8.99 feet?

217. Chemistry

You are given a compound with an unknown concentration and you have five samples with known concentration of the compound. List 3 pieces of information you need to determine in order to calculate the unknown concentration spectrophotometrically.

218. math

A man earns #3500 per month out of which he spends 15 percent on his children's education. If he spends additional #1950 on food, how much does he have left?

219. math

A man earns #3500 per month out of which he spends 15 percent on his children's education. If he spends additional #1950 on food, how much does he have left?

220. math

A man earns #3500 per month out of which he spends 15 percent on his children's education. If he spends additional #1950 on food, how much does he have left?

221. Math

Same kind of problem. How to rearrange to put an equation in quadratic form. Example I'm given is 49.7= 2x^2 / (1.00-x)(2.00-x) which should come out to .920x^2 -3.0x + 2.0 but I can't figure out exactly how to get to there, especially how to get the x

222. Chemistry

Caslcualte the formula massfor each of the following compunds CS2 C6H12O6 Fe(nO3)3 C7H16

223. math

the points x,3 and -2,2 have a slope of 1/4. what is the x-coordinate of the point x,3?

224. COM/330

what are Real-world Systems Theory examples?

225. math

can someone tell me if this is right T=1/5(x-y+z) = x+z-y and can someone please help me with this one F(x)=x^2-6x-27 / x^2-1

226. physical science

Boyle’s law states that if you squeeze a fixed amount of a gas into a smaller volume, the pressure will increase. Explain why?

227. English

1. I go to a museum to see pictures. 2. I go to a museum to watch pictures. 3. I go to a museum to look at pictures. (Which one is commonly used?)

228. english

what would a thesis statement be for Old Jules by Mari Sandoz

229. math- exponents and logs

5,000=55.66 (1.114)^x (i.e. What is x?) ln 5,000= x ln 55.66 1.114 I keep getting 2 point something, but does this make sense? My calculator display looks like this: ln 5000/ln (55.66)(1.114)

230. physical chemistry

This question is about a lab called Heats of Ionic Reaction in my Physical Chemistry class. I need to know why there should be a large percentage error in deltaH4

231. Maths

The sum of two whole number is 23.The different between them is 5.What is the smaller number?

232. Algebra

How many integer values of x are there such that |x-3| + 5 < 16 ?

233. Math

What times what equal 60 and adds to get 7

234. math

Red=1 blue=1 Hans spent 6 minutes painting each of his fence posts. What fraction of his fence posts did he paint red and blue? How long did it take him to paint the red and blue posts?

235. Maths

The sum of two whole number is 23.The different between them is 5.What is the smaller number?

236. math help! Help!

The doctor estimates that more than 220 of the 500 patients in his database take a vitamin each day. A random sample of 60 patients shows that 27 of them take a vitamin each day.

237. math

f(x)=x^2-6x-27 over x^2-1 find the domain T=1/5(x-y+z)

when a teacher tells you whats your novel, what does he or she mean?

239. Analytic Geometry - Reflecting points over lines

Let P = (5,1), and let Q be the reflection of P over the line y = 1/2x + 2. Find the coordinates of Q. I don't understand how to start? Should we draw perpendicular lines?

240. Algebra

x and y satisfy 2^x = 5 and 5 ^ y = 64. What is the value of xy?

What is a 2nd grade pronoun definition

242. math

hi my name is Hannah and I need help with my math homework it is something to do with multiplying trapezoids and triangles? Also, what are the formula for the shapes so that way i would be able to do my homework? THANKS FOR THE HELP!!!!!!

243. math

an athlete can run 6 miles in 51 minutes. at this rate, approximately how far could the runner go in 1.5 hours

7. The doctor’s assistant claims that at least 350 of the 500 patients have seen the doctor in the past year. A random survey of 45 patients shows that 18 have seen the doctor in the past year. Is the assistant’s claim likely to be valid? Explain.

245. Shayna

Find the value of a so that the function f(x) = xe^(ax) has critical point at x = 9 I found that the derivative is axe^(ax)+e^(ax) But I am not sure where to go from here?

246. chem

two cells are connected in series.one contains alcl3,and the other contains agno3 as the

247. human resources

Some recent studies indicate that nine out of ten employers observe the electronic behavior of their employees, from tracking their Web-surfing habits to implanting GPS tracking chips in their arms. Discuss whether managers are justified in monitorin

248. math

F(x)=x^2-6x-27 over x^2 -1 is the answer -4 and for T=1/5(x-y+z) is this answer correct x+z-y

249. math

hi i wanted to know what is 1.8387 rounded three decimal places please im stuck

250. calculus

Find the derivative of the function. f(x) = 9/((7x^2-12)^(1/2))

251. Calculus

Suppose that 3

252. math

an example of play that relates to a curriculum standard in mathematics for preschoolers?

253. algebra

4.782 X 10^13

254. math

-5x-2.34=5.9 i got x=-1.648 is that correct what is -13=10-x/2 i don't understand how do you solve this?

255. Algebra

What are the sum of the roots of f(x) = x^2 - 16x + 63?

256. algebra

simplify x+2/3x-6 * x^2-3x+2/x^2-x-6 and -7/2 + 3-x/x

257. English

The central theme in both "Steal Away" and "Go Down, Moses" is: A: Sinners will pay for their sins. B: slaves will one day be free. C: God has a thunderous voice. D: Slaves should be obedeint. Answer C ?

258. math

Mia gave 1/3 of her 24 marbles to david. how many did daviv get? I said 8

259. math

how meany days are left in school 12:40pm 3/4/2013

260. English

For the speaker in "Local Sensibilities," pineapples represent: A: his favorite food. B: a Thankgiving ham. C: tourist D:work Answer B ?

261. psychology

A friend of mine finished fourth in her age group in the world duathlon (run, ride, run). She has two bicycles that differ along several variables, but she isn’t sure which one will be best for the next season. How could she find out? Write the methods

262. math

1 can OJ is 15% 1 can is 10% how many liters of each should be mixed together to get 5 liters at 13%

263. Psychology

I know a man who read to his 5 children every night before they went to bed, and they all could read before entering preschool. Suppose that this were true of all children we could find who were read to every night before going to bed but true of only a

264. psychology

The first year after the speed limit was reduced to 55 mph was the first year since there was a federal speed limit that no one in the United States who was observing the speed limit died in an auto accident. What does this prove?

265. math

-5x-2.34=5.9 i got x=-1.648 is that correct what is -13=10-x/2 i don't understand how do you solve this?

266. chemistry

A white solid was found in an unmarked bag. Describe an experiment that can be set up to determine if the solid is either MgSO4*10H2O or KCL*2H2O

267. Stat

Suppose there are 2 black, 3 white, and 5 red marbles in an urn. You reach in and randomly select 3 marbles without replacement. And let X be the number of black marbles. Find the probability table for X.

268. Physics II

It is ~ 100 miles of mostly interstate driving to camp. Using your model from parts (b) and (c), how much does it cost me to drive to camp if I drive 55 mph, 65 mph, and 75 mph? (don’t forget the return trip) the current price of gas for part c is

269. Physics III

The “average” driver drives ~15,000 miles per year. Let’s assume ~10,000 miles of that is interstate driving. Using your models from parts (b) and (c) again, how much does the average driver spend per year if their average speed is 55 mph, 65 mph,

270. KittyKitKatKoo

Does anyone know why the Germans might not have talked about the Holocaust until years after the war had ended? Thanks!!

271. math

what is 117.04 in scientific notation

272. Calculus

Given that \displaystyle \int_0^4 x^3\sqrt{9+x^2} dx = a, what is the value of \lfloor a \rfloor?

273. psychology

Suppose that you have developed three new kinds of hair shampoo, and you want to know how people's preference depends on their age. Design an experiment to find out.

274. math

x+2/3x-6*x^2-3+2/x^2-x-6

6x^2-x-15

276. algebra 2

A diamond is purchased for \$3500. Its value increases 5% each year. Find the value of the diamond after six years.

277. Math

What is 75/31in simplest form

278. Calculus

At what value of x does the graph of y=9x^(1/3)+x^2 have a point of inflection?

279. trig

use an angel sum identity to verify cos2theta = -2cos^@-1

280. English II

Expand each sentence below by adding words or phrases that modify the verb. Questions after each item suggest details you can add. 1.Prehistoric paintings were found. 1. How were the paintings found? 2. Where were the paintings found?

281. college chemistry

if my sublimation apparatus imploded, what was the cause of it?

282. World History

What is the significance of Roger B. Taney ?

283. algebra

-2x-4y=1 12y=-6x-3 I have to find the solutions, or no solution, or infinite solutions to these two equations.

284. physics

Suppose we have |ϕ⟩=∑y∈{0,1}nβy|y⟩ such that βy=0 if s⋅y=1mod2 and βy=12(n−1)/2 if s⋅y=0mod2, where s is some hidden n-bit string. (a) If we run Fourier sampling on |ϕ⟩, what is the probability that we see s?

285. math

solve for v round your answer to the nearest tenth 13/7= v/8

286. Maths

Help me rearrange this equation, v=20-9.8t

287. math

what is the formula for working out open cuboid.

288. math

what is the formula for working out open cuboid.

289. math

To make one bowl of party punch. 4 3/4 cupps of soda is used. How many cups of soda would you need to make 3 bowls of party punch?

290. math

Kevin Made five shirts. Each shirt used 2/3 yard of cloth. How many yards did he need in all?

291. Geometry

line xy bisect and is perpendicular to ab and cd. ab=6 and ap=5 what is the length of xy

292. physics

Sara walks at 1.50 m/s. She notices Emily is standing at the coffee shop ahead so she accelerates at 1.55 m/s ^2. How far is emily ?

293. math

what is 5-2x=13+2x

294. finding the x value

Find the value of x 19 x 27