Posts by Stephanie

Total # Posts: 1,235

Chemistry. Help please
Calculate the pH of a buffer solution made by mixing 174 mL of a 1.68M trimethylamine (CH3)3N solution with 250 mL of a 1.08M trimethylammonia chloride, (CH3)3NHCl solution.

break apart these numbers 40x16

Chemistry. please help
A 0.12 g sample of unknown was placed in a flask and dissolved in 125 mL of deionized water. A solution of HCl (0.10 M) was used to titrate the sample, and 18 mL was required to reach the endpoint. What is the formula weight of the unknown?

Write the 12 mole ratios that can be derived from the equation for the combustion of isopropyl alcohol?

solve for x 5 + x 10 ----- = ---- x 8

determine the perimeter of triangle KLM, if triangle KLM-triangle FGH, FG=30, GH=38, FH=38 and KL=24

What role did the geography of europe play in the development of and ways of life in these towns?

When dissolved in an aqueous solution, which of the following salts will yield a neutral solution? Choose one answer. a. KCN b. NaHSO4 c. Na3PO4 d. AlBr3 e. MgBr2

One of the most obvious ways to tell that a chemical reaction has occurred, as we all know, is that the color of 'stuff' changes. Ligand exchange reactions are one class of reactions where this is very evident, as exemplified by the color change of a green Ni(H2O)62+ ...

I posted a question at 5:43pm yesterday...can anyone please help with at least some of it? Thank you so much.

I really appreciate your help.

I have spent all afternoon (on Thanksgiving, no less) trying to figure out these post-lab questions. We had to produce a precipitate of a reaction of: 1) 1 ml 1M Na2SO4 + 9mL 1M CaCl2 Our result was .569g 2) 5 ml 1M Na2SO4 + 5 ml 1M CaCl2 Our result was .01g 3) 9 ml 1M Na2SO4...

When tossed upward and hit horizontally by a batter, a 0.23 kg softball receives an impulse of 2.0 N·s. With what horizontal speed does the ball move away from the bat?

A horizontal force of 25 newtons pushes a box a distance of 30 meters across the floor. How much work is done by the force?

Which one supports the solar nebula theory of the origin of the solar system? a.Disks are rare around young stars. b.Disks are common around young stars. c.The sun is the least massive object in the solar system. d.Planets are round.

thank you! I just thought that just because jupiter is a gaseous planet that it would have a lesser mass.

Sevnety-eight players entered a single elimination tennis tournament.How many matches were played to determine the overall champ? please help me...and if u get the answer can you explain how you got it with a rule or a pattern

replacing with possessove nouns ex the sister Miguel woke up him. Miguel's sister woke up him

11th grade
At a glassware factory, molten cobalt glass is poured into molds to make paperweights. Each mold is a rectanglar prism whose height is 3 inches greater than the length of each side of the square base. A machine pours 20 cubic inches of liquid glass into each mold. What are the...

given triangle QRS=triangle TUV, QR=2x=7, RS=13,and QS=3x+2 and TV=7x-6 find the value of x

thanks guys, but arethere any objects you think i can bring to school?

are there any objects that represent perseverence? and why? i need this for an english projcet

college microeconomics
Suppose that two players are playing the following game. Player 1 can choose either top or bottom, and Player 2 can choose either left of right. The payoffs are given in the following table Player 2 Left Right top 9,4 2,3 Player 1 Bottom 1,0 3,1 where the number on the left is...

do the FOIL method f for first o for outer i for inner l for last (8y+5z)(8y-5z) 64y^2 + 40yz - 40yz + -25z^2 64y^2 - 25z^2

the answer is c

-2 3/4 - 6 5/9=

2 2/3 + -1 1/2=

help!!! physics
you want to nail a 1.6 kg board onto the wall of a barn. to position the board before nailing, you push it against the wall with a horizontal force to keep it from sliding to the ground. (a) if the coefficient of static friction between the board and wall is .79, what is the ...

a .15 kg ball is placed in a shallow wedge with an opening angle of 120 degrees. for each contatct point between the wedge and the ball, determine the force exerted on the ball. assume the system is frictionless.

Let mass of hanging block be M Since in equilibrium the hanging mass MG = Tension in the wire Similarly along the incline Tension in the wire = 6.7 * g * sin 42 (Component of force along the incline) So equation both the equations: M*g = 6.7 * g * sin(42) M = 6.7*sin(42) So M...

two blocks are connected by a string. the smooth incline surface makes an angle of 42 degrees with the horizontal, andthe block on the incline has a mass of 6.7 kg. find the mass of the hanging block that will cause the system to be in equilibrium. (the pully is assumed to be ...

when you solve a system of equations by the substitution method, how do you determine whether the system of equations is dependent?

Well, we know x=3 and y=8 and dx/dt=4. We need to find z (the distance from the particle to the origin) dy/dt, and finally our answer dz/dt. First solve for dy/dt y=2(3x+7)^(1/2) dy/dt=[2(1/2)(3x+7)^(-1/2)](3dx/dt) dy/dt=[(3x+7)^(-1/2)]3dx/dt dy/dt=[(3(3)+7)^(-1/2)](3(4)) dy/...

strontium nitrate reacts with potassium iodate. What is its molecular,ionic and net ionic equations?

1.test wheter these samples represent populations that are different from the general population- sample of 10 with a mean of 44 and sample of 1 with a mean of 48. 2. The general population of individuals has a mean of 40 , a deviation of 6, and follows a normal curve. for ...

The following is given: 20 ml of HCl (2.0 M) added with 5 ml of Na2S2O3 (0.3 M) with 5 ml of H2O S2O3^-2(aq) + 2H^+1 (aq) --> S (s) + SO2 (g) + H2O (l) Calculate the following: a) Reaction rate when 30 mg of sulphur is formed (in 30 ml of solution) after 55 seconds. b) Rate...

the ratio of two integers is 9:7. their sum is 1024. find the two integers.

Thanks again. Believe I have hang of it now.

My last two that are confusing me. Identify verb and tell if transitive or intransitive. 1) Most people think of bamboo as a tree or a bush. 2) Bamboo belongs to the grass family. 1) think=intransitive 2) belongs=intransitive

Thank you very much.

Please check and see if I answered correctly. Have to identify the verb and tell if intransitive or transitive 1. In China people eat the tender shoots as a vegetable. 2. The Japanese also make flutes from the stems. 3. In some countries, bamboo cages hold animals.

Actually there are 3600seconds per hour. So the answer of 29.06m/s is correct.

A 287-kg log is pulled up a ramp by means of a rope that is parallel to the surface of the ramp. The ramp is inclined at 30.0° with respect to the horizontal. The coefficient of kinetic friction between the log and the ramp is 0.810, and the log has an acceleration of 0....

Pluto has a mass of 1.30 1022 kg and a radius of 1.18 106 m (a) What is the acceleration due to gravity on Pluto? (b) How much would a 4.7-kg person weigh on this planet?

3rd grade

how can i use appositives in a conservation with a friend

A volleyball is deflected vertically by a player in a game housed in a high school gymnasium where the ceiling clearance is 18m. If the initial velocity of the ball is 21.5 m/s, will the ball contact the ceiling?

A ball is kicked at a 37 degree angle, with a velocity of 14.6 m/s. How high and far does the ball go?

6th grade science
this website barley actually does any homework help

i need help What does It mean to be an american citizen ?

college economics
Assume Nebraska and Virginia each have 100 acres of farmland. The following table gives hypothetical figures for yield per acre in the two states: Nebraska Virginia Wheat 15 5 Cotton 7 4 Who has the comparative advantage in the production of wheat? *For this answer, I think it...

3 English H
How can I illustrate the word "aberration"?

algebra 1 honors
it says simplify each expression. justify each step. 1. (2 + 7m) + 5 2. 9 x (r x 21)

Identify the fruit or vegetable you selected and relate the second law of thermodynamics to the changes in energy observed in Appendix C. How did the amount of energy gained compare to the amount of energy lost as heat at the second through fourth trophic levels? o Answer the...

putting function machines in order. completely don't understand.

Explain why the statement is incorrect: The probability that a bus will arrive late at the Civic Center is 0.35 and the probability that it will be on time ore early is 0.60

I am having a hard time coming up with several sentences about an interaction with a friend or family member about personal finance or credit cards that includes five different pronouns, adverbs, and adjectives. Can anyone help me?

Math-please check my answer
That is correct! Great job!

If VZ = 21, ZX = 24, and Z is the midpoint of WY, what is the length of WZ rounded to the nearest tenth?

What is meant by the term utility and how does it relate to purposeful behavior

Find the volume of a cylinder with radius 6 cm and height 10 cm. Use 3.14 for ð. Round your answer to the nearest tenth.

does champva provide adequate level of health insurance for participants

British Literature
14. Realism was largely a reaction against >> D) Romanticism 15. Realism is associated with >> D) all of the above Those are the ones I can do easily now. I've never read the stories in here, though I recently finished a big-ass British literature course :O

A .6-kg mass at the end of a spring vibrates 3.0 times per second with an amplitude of .13 m. Determine a.) the velocity when it passes the equilibrium point, b.) the velocity when it is .1 m from equilibrium. c.) the total energy of the system, and d.) the equation describing...

1. Identify the degree, leading term and leading coefficient of each polynomial function. A. f(x)= x(x+1)(3x+1)(x-2) B. f(x)= -16+3x^4 - 9x^2 - x^6 + 4x^8 2. Describe the end behavior of a ninth-degree polynomial function with a negative leading coefficient.

6x-4y=8 have to find the slope for that equation, and the y-intercept, so I'll start with x=0

when 25.0 g of Zn reacts how many L of H2 gas are formed at STP

12.5 L

a sample of H2O with a mass of 46.0 grams has a temperature of -58.0 degress celcius. how many joules of energy are necessary to melt 46.0 grams of ice?

what is the solubility of Ag in water at 0 degrees celcius? what is it for calcium carbonate? and yellow brass?

A0 2.95 cm3

US History
Where were some of the great achievements created by the enormous growth of American cities in the last decades of the 19th century?

Billing and Coding
How do you know what the main term is in a multiple-word diagnosis? Example: Acute Fulminating Multiple Sclerosis

English /Lit
Using literary elements,compare and contrast Abigail Adams letter to her daughter with Jean de Crevecoeur's essay from letter to an American farmer. Now i read both essays, and im very fond of both of them . but i have trouble on what to compare and contrast on them, and ...

5th grade
Carol uses the same ratio table to solve the problems below. Do you agree or disagree? 8 cows/2 pigs = c cows/10 pigs 2 pigs/8 cows = 10 pigs/c cows

COMM/215 Final Grammar exam, please help
Please help me out with my final grammar exam, COMM/215 Thank you

Can you please tell if the follong questions are true or false (fragment) 1. That movie, one of my favorites, true or false? 2.-The local baseball team, needing a good picher true or false? 4.- Using a flashlight, he looked under the bed for his shoes true or false, thank you

college chemistry
A) In some regions of the southwest United States, the water is very hard. For example, in Las Cruces, New Mexico, the tap water contains about 560 ug of dissolved solids per milliliter. Reverse osmosis units are marketed in this area of soften water. A typical unit exerts a ...

college chemistry
A solid consists of mixture of NaNO3 and Mg(NO3)2. When 6.50 g of this solid is dissolved in 50.0 g of water, the freezing point is lowered by 5.40⁰C. What is the composition of the solid (in mass percent)? Assume ideal behavior but watch out for the van’t Hoff factor.

college chemistry
Pentane, C5H12, and hexane, C6H14, combine to form an ideal solution. At 25⁰C the vapor pressure of pentane is 511 torr and that of hexane is 150 torr. In the vapor over a pentane-hexane solution at 25⁰C, the mole fraction of pentane is 0.15. What is the mole ...

college chemistry
If gaseous H2 and O2 are carefully mixed and left alone, they can remain intact for millions of years. Is this “stability” a function of thermodynamics or of kinetics? Give a valid reason to support your choice.

college chemistry
a) Is the reaction shown below spontaneous under standard conditions at 25⁰C? CH3OH (g) ----> CO (g) + 2H2 (g) b) Will this reaction be spontaneous at 25⁰C given the following amounts of materials? CH3OH at 1.20 atm CO at 0.080 atm H2 at 0.020 atm

college chemistry
Sodium chloride is added to water (at 25⁰C) until it is saturated. Calculate the Cl- concentration in such a solution. Useful data are provided below. ∆G⁰f (kJ/mole): NaCl (s) -384 Na+ (aq) -262 Cl- (aq) -131

college chemistry
Carbon monoxide is toxic because it bonds much more strongly to the iron in hemoglobin (Hgb) than does O2. Consider the following reactions and approximate free energy changes: Hgb + O2 ---> HgbO2 ∆G⁰ = -70 kJ Hgb + CO ---> HgbCO ∆G⁰ = -80 kJ ...

college chemistry
A zinc-copper battery is constructed as follows: Zn | Zn+2(0.10 M) || Cu+2 (2.50 M)| Cu The mass of each electrode is 200.0 g. Each half cell contains 1.00 liter of solution. a) Calculate the cell potential when this battery is first connected. b) Calculate the cell potential ...

college chemistry
Cadmium sulfide (CdS) is used in some semiconductor applications. It is possible to evision the dissolving of this slightly soluble substance as an oxidation-reduction reaction. Calculate the value of the solubility (Ksp) for CdS given the following standard reduction ...

A standard voltaic cell is constructed so that the overall cell reaction is 2Al+3(aq) + 3M(s) --> 3M+2(aq) + 2Al(s) where M is an unknown metal. If ∆G⁰= -411 kJ for the overall cell reaction, identify the metal used to construct the standard cell.

what colors do you associate with the following words and phases? el invierno, el verano, la primavera, el ortorio, los peces tropicales, el perro Osito, Rosario

A siren mounted on the roof of a firehouse emits sound at a frequency of 900 Hz. A steady wind is blowing with a speed of 15 m/s. Take the speed of sound in calm air to be 343 m/s. (c) Firefighters are approaching the siren from various directions at 15.0 m/s. What frequency ...

9th grade

Organic Chemistry
A student tried to dissolve 5.0 grams of impure acetanilide in 50 Ml of hot water. However was not able to get it to dissolve. Why not? What would you do to get it to dissolve??

THANKS MATT! I'm in your class too! haha, this totally helped. haha

AlgebRA / MATH

Find the derivative of y=cos(squarerootsin(tzn(pi*x)))

Physical Science
Consider the current-carrying wires in the figure. Both cases consist of long straight wires carrying a current I. In both cases, the wire is also bent in the shape of a circular loop of radius R. The only difference is in how the bending of the wire is done to create the ...

during what part of bernice bobs her hair does bernice cut Marjories braids

give the prime factorization of 189

Physical Science
The frequency of circular motion for a charged particle moving around in the presence of a uniform magnetic field does not depend on ... a)The radius of the circle b)The mass of the particle c)The charge of the particle d)The magnitude of the magnetic field e)Actually, it ...


Physical Science
Two parallel transmission wires are laid between electrical towers. The distance between towers is 200 m, while the separation between the parallel wires is only 2.5 m. If the wires carry each a current of 1000 A, the magnitude of the force between the wires is closest to ... ...

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