# Posts by lynn

Total # Posts: 602

Math
Harry lost 15p, which was 3/4 of his money. How much had he at first?

Chemistry
the Ka values are given in the question from the homework. Ka1 = 0.0560, for the equation: HOOCCOOH(aq) = HOOCCOO-(aq) + H+(aq) While Ka2 = 0.0145, for the equation: HOOCCOO-(aq) = -OOCCOO-(aq) + H+(aq)

Chemistry
What is the pH of the solution if 0.015 mol of HCl is added to a buffer containing 0.014 mol of RCOOH and 0.033 mol of RCOONa (source of RCOO-)? Ka = 2.8E-5 I have tried the following: adding 0.014 + 0.015 = 0.029 ph = pka + log (Base/Acid) pH = -log(2.8E-5) + log(0.033/0.029...

Chemistry
What is the Pb2+ concentration in a saturated solution of PbCl2 if the concentration of chloride ion is 0.023 M? Units: M ksp = 1.72x10^-5 i can't seem to get the answer. i have tried and ICE diagram and going from there: PbCl2 (s) <--> Pb ^2+ = 2Cl- I: 0.023 M = Cl...

Chemistry
What is the hydrogen ion concentration of a 0.22 M hypochlorous acid solution with Ka = 3.5E-8? The equation for the dissociation of hypochlorous acid is: HOCl(aq) = H+(aq) + OCl-(aq). I keep getting 3.60 as the concentration, but that is the wrong answer. Using ICE: Eq: HOCl...

Chem
A tablet containing calcium carbonate and fillers with a mass of 1.631 g was dissolved in HCl. After the fillers were filtered out, the HCl was neutralized by adding sodium carbonate. The resulting precipitate was pure calcium carbonate (with the fillers removed). The solid ...

Chemistry
So far i have done the following: Ln of (concentration A divided by Concentration A at time 0) = -k * T natural log (0.0174 M / 0.0693 M) / -489 sec which equals to 2.826 x10^-3 s-1

Chemistry
Hydrogen iodide decomposition via a second-order process to produce hydrogen and iodine according to the following chemical equation: 2 HI(g) -> H2 (g) + I2 (g) If it takes 489 seconds for the initial concentration of HI to decrease from 0.0693 M to 0.0174 M, what is the ...

8th Social studies

history
What was the last christian city conquered by the Muslims.

Chemistry
Is calculating the sloope of the tangent line the same as calculating the slope? (y2-y1) / (x2/x1) for instance if i took the points 60, 0.023 for X1Y1 and points 100, 0.034 for X2Y2, the slope of the line would be : (0.034-0.023) / (100-60) = 0.011/40 = 0.000275 (the slope...

Chemistry
Using the following data, determine the initial rate by calculating the slope of the tangent line at time zero. Time (s). [I2] (mM) 0. 0 20. 0.009 40. 0.017 60. 0.023 80. 0.029 100. 0.034 120. 0.039 140. 0.043 160. 0.046 180. 0.049 I can't figure out how to make a tangent...

Social studies
thg is right

Math
Jenny's lawn is 1/3 of an acre. After moving 1/2 of the lawn, how much of an acre has she mowed? A. 1/5 B. 1/6 C. 1/2 D. 2/5 ______________________________ A leaking bucket is filled to 3/4 capacity. After some time, 1/2 of the water has leaked out. What fraction of the ...

Algebra
After thinking about it, two negatives cancel out to be neutral so the answer is D. No need for any feedback now.

Algebra
A line has slope -5/3. Through which two points could this line pass? A: (12,13), (17,10) B: (16,15), (13,10)*** C: (0,7), (3,10) D: (11,13), (8,18)*** My Explanation: I know how to use the formula for slope, which is y2 -y1 over x2 - y2, so I know how to solve the problem. ...

Trig
Find the exact value of the trigonometric function given that sin u=3/5 and cos v=-8/17. Both u and v are in quadrant II. Tan (u+v)

Math

Math
Sarah has to go to her brother's baseball tournament that lasts for 4 days. She eats two-thirds of a hotdog at every game. He plays 2 games a day. Define your variables, write a function rule, find the domain and range, and tell whether the data is discrete of continuous. ...

Math
The number is closer to 60 than to 70. It is one number closer to65 than 68 is.

Biostatstics
Question: The New York State Health Department reports a 10% rate of the HIV virus for the “at-risk” population. Under certain conditions, a preliminary screening test for the HIV virus is correct 95% of the time. (Subjects are not told that they are HIV infected ...

Financial math
Janet Woo decided to retire to Florida in 5 years. What amount should Janet invest today so she can withdraw \$45,000 at the end of each year for 20 years after she retires? Assume Janet can invest money at 5% compounded annually.

Maths
Both of the digits is even. One of the digit is 4. The tens place is twice the amount of the ones place. The number is less than 70. What is the number?

Math
I have a square house that has 1130 square feet, what is the dimension?

algebra Please c if this is right?
Mrs. /green is randomly choosing team captains from her class of 12 girls and 10 boys. ?She draw one name from the bag, SETS IT ASIDE, and then chooses a second name. /What is the probability that both team captains are girls? I would say it is 2/7 Can someone check to see if ...

english
Paint

Math
Thanks Damon.

Math
Is this correct? Divide the reciprocal of -9 by the opposite of -9. This is my answer -9/1 / -9 -1/9 / 9 -1/9 * 1/9 = -1/81

Math
Thank you.

Math
I need help. Solve the proportion: 4:x :: -3/8:12

Language Art's
gracious human is 100% correct thank you

math
The Jacobys went on a 600-mile trip. On the first day they drove 5 3/4 hours and on the second day they drove 4 3/4 hours. How many hours did they drive during the first two days?

Math
11.5

Algebra 1 help
Christine is correct! I was struggling for the answer on question 2. Thank you!

what expression represents a number n divided by eight increased by five? n/8+5 is this correct?

economics
Think about how each scenario would affect the price of khaki pants. a.A new technology reduces the time it takes to make a pair of khaki pants. b.The price of the cloth used to make khaki pants falls. c.The wage rate paid to garment workers increases. d.The price of jeans ...

English
All these sentences look right to me. Which is incorrect? Identify the incorrect sentence. A. The jury has been deliberating for the past three hours. B. Members of the jury have been deliberating for the past three hours. C. The jury is arguing over the evidence. D. Members ...

math
Explain why an even function does not have an inverse that is a function. and if log b < 0, what can you say about b?

Maths
Find the first four terms in the binomial expansion of (1+x)^(1/5) and state the range of values of x for which this expansion is valid.Hence approximate (31)^(1/5) correct to four decimal places.

Maths
Find the first four terms in the binomial expansion of (1+x)^(1/5) and state the range of values of x for which this expansion is valid.Hence approximate (31)^(1/5) correct to four decimal places.

Maths
A ball is dropped from a height of 80ft.The elasticity of this ball is such that it rebounds three-fourths of the distance it has fallen. How high does the ball rebound on the fifth bounce? Find a formula for the height the ball rebounds on the nth bounce?

Physics
A stone is thrown upwards from the roof with a velocity 15ms^-1 at an angle 30degree to the horizontal. The height of the building is 40m.calculate the magnitude of the velocity of the stones before it strikes the ground

Physics
A particle moving with uniform acceleration has initial velocity u. With the aid of a velocity time graph, show that the displacement s after time t is given by: s=ut+1/2*gt^2

HELP!! Statistics!
The accompanying data table lists measured voltage amounts supplied directly to a family’s home. The power supply company states that it has a target power supply of 120 volts. Using these home voltage amounts, test the claim that the mean is 120 volts. Use a 0.05 ...

INTERVAL OF THE MEAN
In a test of of garlic for lowering cholesterol, 45 subjects were treated with garlic in a processed tablet form. Cholesterol levels were measured beforeandafter the treatment. The changes in their levels of LDL cholesterol (in mg/dL) have a mean of 5.4 and a sd of 17.5. ...

Statistics HELP!
Use a normal approximation to find the probability of the indicated number of voters. In this case assume that 119 eligible voters aged 18-24 are randomly selected. Suppose a previous study showed that among eligible voters aged 18-24, 22% of them voted. The probability that ...

Statistics
If np ≥ 5 and nq ≥ 5, estimate P (fewer than 4) with n = 13 and p = 0.5 by using the normal distribution as an approximation to the binomial distribution; if np < 5 or nq <5, then state that the normal approximation is not suitable. P (fewer than 4) =

trig
Find the bearing and airspeed for a plane to fly 630 miles due north in 3 hours if the wind is blowing from a direction of 318* and is blowing at 15mph. Approximate the bearing to the nearest degree and the speed to the nearest mile per hour.

Algebra 1
x/2=10+ 2y/3

Chemistry
23°C

Math- Calc 1
1. At what point does the normal line to the curve x^2 - XY + Y^2 = 3 at the point (-1,1) intersect the curve again? 2. Find the constants A, B so that if Y=A*sin X + B cos X, then Y satisfies the differential equation Y" + 2Y = 0. 3. Find the points on he graph of Y = e^...

Math- Calc 1
1. At what point does the normal line to the curve x^2 - XY + Y^2 = 3 at the point (1,1) intersect the curve again? 2. Find the constants A, B so that if Y = Asin X = B cos X, then Y satisfies the differential equation Y" + 2Y = 0. 3. Find the points om he graph of Y - e^...

algebra
An alligator’s tail length, T, varies directly as its body length, B. An alligator with a body length of 4.5 feet has a tail length of 2.5 feet. What is the tail length of an alligator whose body length is 5.4 feet?

psycholigy
Cultural learning involves all aspects of the learning processes that psychologists have identified over the years, such include: a. classical conditioning b. operant conditioning c. social learning d. All of the above.

Chemistry honors
20 grams magnesium metal react with excess oxygen and 28 grams of magnesium oxide are produced in lab what is percent yield? If 99.8 g of aluminum nitrate are reacted with excess sulfuric acid what would be the theoretical yield in grams of aluminum sulfate? i have done both ...

Physics
a (n) 1510 kg car is moving along a level road at 13.8 m/s. The driver accelerates and in the next 10s the engine provides 23400 J of additional energy. If 3900 J of this energy must be used to overcome friction, what is the final speed of the car?

Algebra
Ticket Sales. Stacey is selling tickets to the school play. The tickets are \$7 for adults and \$4 for children. She sells twice as many adult tickets as children's tickets and brings in a total of \$306. How many of each kind of ticket did she sell?

Math
Sara wants to put new carpet. She needs 20 square feet. the carpet was \$4.00 a square foot. She got it for half price. What was the new cost of the carpeting? And the total?

Stats
A random sample of 100 GMAT scores has a mean of 500. Assume that GMAT scores have a population standard deviation of 120. Construct a 95% confidence interval estimate of the mean GMAT scores. (15 pts) What is the sample size for the conference interval? What is the point ...

medical coding2
does anyone know the answer the this coding question? This 42 Year Old White Male Who Accidentally Injured His Left Finger On A Circular Saw While Working O At Home In His Garagen Broken Shutters

Calculus
"Three hundred books sell for \$40 each, resulting in a revenue of \$12,000. For each \$5 increase in price, 25 fewer books are sold. Write revenue R as a function of the number x of \$5 increases." How would you get this problem started?

Geom
Given 70 degrees on a clock tell what time it is

algebra
I was looking for the estimated answer not the correct answer or formula to estimate

algebra
7 1/5 divided by 3/5 estimated

algebra
A manufacturer of birds feeder cut spacers from a tube that is 7 1/5 inches long. How many spacers can be cut from the tube if each spacer must be 3/5 inch thick. The estimated answer is?

algebra
p=b+a+c b=

algebra
z=yn y=

algebra
13x+2>3((2x+1)-x+8

algebra
x=1

algebra
3x+6+x<1+2x-5

algebra
P=a+b+2c for a

Physics
A heavier mass m1 and a lighter mass m2 are 20.5 cm apart and experience a gravitational force of attraction that is 8.60 10-9 N in magnitude. The two masses have a combined value of 5.80 kg. Determine the value of each individual mass.

physical science
bombarded by high-speed electrons.

math
You need to hire a part-time associate to work 30 hours a week in your store. You have \$250 in labor budget for the new associate each week. You just interviewed an excellent candidate for the position who has requested to be paid \$9.00 per hour. Your average part-time ...

history

Chemistry
My question is ..can anyone explain how to do problem #2? I feel lost. :( And could you also explain why? Problem#1, is that a regular dG = dH - TdS problem? Then using Go = -RTlnK to find K? Im just afraid if there are other seps to it.. 1. The combustion of butane has the ...

Chemistry
I got it! I was using the incorrect Kb for each of the reactions! Thanks so much!!!

Chemistry
Okay, thank you! I will try this method!

Chemistry
Calculate the concentrations of all species in a 0.390 M Na2SO3 (sodium sulfite) solution. The ionization constants for sulfurous acid are Ka1 = 1.4× 10–2 and Ka2 = 6.3× 10–8. Species: Na+ SO3 2- HSO3 - H2SO3 OH- H+ Thanks! The only thing I seem to be ...

Finance
Thanks for the help and explanation!

Finance
Kim has money in a savings account that earns an annual interest rate of 4.1%, compounded monthly. What is the effective rate of interest on Kim's account? Round to the nearest hundredth of a percent.

science
an individual's actual appearance. may include physical characteristics, microsoptic or metabolic charisteristics

finance
Thanks for the explanation Henry!

finance
For a \$13,000 student loan with a 6% APR, how much of the payment will go toward the principal and how much will go toward paying interest for each of the first six payments? Assume this is a 10-year loan with monthly payments.

Liberal Arts Math II
How long is the perimeter of a snowflake island? A) it is the same as the area B) it is infinite C) 2 times the height D) 3 times the height

Thanks for your help, I read over the others and also dug a little deeper in my book and I think that's the best choice as well.

Okay, I have eliminated A & D

Initially I thought Gramm-Leach-Bliley Privacy Act but I don't see this in my book.

What statute requires banks and other financial institutions to disclose to consumers any non-public information they wish to reveal to third parties? A) Banking and Financial Institution Privacy Act. B) Gramm-Leach-Bliley Privacy Act. C) Electronic Communications Privacy Act...

You make an online purchase of a hooded sweatshirt with the logo of the Dallas Cowboys. The next time you log on, your screen has a banner ad for Dallas Cowboy hats and shirts. This banner ad is most likely the result of: A) a cookie. B) a coincidence. C) the Internet crime of...

Liberal Arts Math II
Choose one of the following statements to complete the sentence. Discuss your reasoning for your selection. Euclid’s treatment of the fifth axiom... A) ... shows that it is important to question the nature of the assumptions that are made. B) ... is now known to be wrong...

Yi conveyed a piece of land by general warranty deed. The deed included a covenant of seisin. With this covenant, Yi promised that: A) she has the power to make the conveyance. B) the land is free from any easement, profit, mortgage, etc. C) no other person can lawfully claim ...

Ross is a wealthy man. Out of the kindness of his heart, he transfers a piece of real property to his church, "for as long as the property is used for church purposes." Ross has created which of the following ownership interests? A) Life estate to the church; ...

Math
problems with words that are is to solve

trig
Thank you so much for the help.

trig
A person stands at a distance from the tower and eyes the top of the tower at 30 degree angle of elevation. He then walks 425 feet towards the tower and eyes the top of the tower at a 58 degree angle of elevation. The person is 5 feet tall. How tall is the tower?

Liberal Arts Math II
The following argument is valid: No student is happy You are happy Therefore, you are not a student A) True B) False

Finite Math
Thank you both. I tried this using the "72 rule" and was discouraged by my answer due to the book answer of 9.64% and I am not sure how that answer is founded.

Finite Math
A person invests \$2000 annually in an IRA. At the end of 6 years, the amount in the fund is \$14000. What annual nominal compounding rate has this fund earned?

Chemistry
Calculate (in calories) the amount of heat needed to melt 96g of ice at -24 degrees C to water at 28 degrees C.

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