# Posts by kate

Total # Posts: 2,021

**AP Chemistry**

A mixture of aluminum and zinc metal is used in 2 experiments described below: A- A 1.7 gram sample of the mixture is reacted with excess hydrochloric acid and the resulting hydrogen gas is collected over water. The reaction takes place at 750 mm Hg atmospheric pressure and ...

**AP Chemistry**

Okay, thank you so much! You really know your chemistry

**AP Chemistry**

Where does the Al(OH)3 come from and how do you know and how do you tell how much of the 2.70g of ppt is Al(OH)3 or Zn(NH3)4^+2?? Thanks

**AP Chemistry**

Im mainly confused on how you know what amount of aluminum or zinc is in the samples of the mixture

**AP Chemistry**

A mixture of aluminum and zinc metal is used in 2 experiments described below: A- A 1.7 gram sample of the mixture is reacted with excess hydrochloric acid and the resulting hydrogen gas is collected over water. The reaction takes place at 750 mm Hg atmospheric pressure and ...

**Chemistry**

Determine the final concentration of 20ml of 5M NaCl of solutions after 30ml of water has been added.

**Physics**

A person stands on a scale in an elevator. As the elevator starts, the scale has a constant reading of 600 N. As the elevator later stops, the scale reading is 396 N. Assume the magnitude of the acceleration is the same during starting and stopping. A)Determine the wieght of ...

**english - Contrast Advertising**

What are some companies that sell produtcs to the average consumer?

**english**

what does this quote mean "We'll have to tighten the belt a little bit and make due"

**science**

what r some good websites to look up river streams ponds lakes wetlands marsh and swaps plants and animals

**math**

try (20*4)+(20*3)

**chemistry**

will the pH be 11.20

**chemistry**

Can you give the steps for working this?

**chemistry**

a 275mL sample of vapor in equilibrium with 1-propylamine at 25C is removed and dissolved in 0.500L of H20. For 1-propalamine, Kb=3.72*10^-4 and the vapor pressure at 25C is 215 torr. (a)What should be the pH of the aqueous solution? (b) How many mg of NaOH dissolved in 0....

**essay**

What are some suggestion regarding should the driving age be raised to 18?

**Physics**

A certain piece of wire has a resistance of 250 ohms. if the wire is cut in three pieces and the cross sectional area of each piece is halved, what is the resistance of each piece?

**geometry**

Quadrilateral QRST has two pairs of congruent sides, but it is not a parallelogram. What figure is it? What further condition would it have to satisfy to be a parallelogram? A. The figure is a square. To be a parallelogram, it would have to have pairs of opposite congruent ...

**geometry**

Can you prove ABCD is a parallelogram based on the given information? Explain. Given: x = 5, y = 4 Prove: ABCD is a parallelogram. A. The figure is a square. To be a parallelogram, it would have to have pairs of opposite congruent sides, not just congruent sides. B. The figure...

**calculus**

How do I find the x values at which the tangents to the graphs f(x)=2x^2 and g(x)=x^3 have the same slope?

**Chem- PLZ HELP!**

Ok that looks wrong. 100g should be under solution for the mass, 18.02g/mol for the solvent of H2O and 85g/mol for the solute of NaNO3. I have to find mass of solute and solvent and the moles of solute and solvent. Pls help anyone!

**Chem- PLZ HELP!**

Consider 100g of 5.5% (mass) solution of NaNO3. Complete the following table, before calculating molarity, molality and mole fraction of NaNO3. Solute(NaNO3)|Solvent(H2O|Soln Mass(g) 100g Moles ---- RefInfo 85g/mol 18.02g/mol Density=1.00g/mol (This goes under "soln"...

**english**

what are some Controversia topics in regards to what is happening in the news currently?

**SCience**

Would you want someone looking through CLEAR GLASS at you? I think not. . .

**Saint Louis University**

He probably misread it to be "your school"

**World History**

I actually have a fairly good paragraph for the cultural aspect, but I'm not so sure where I should start for it economically. . . .

**World History**

How did a newfound sense of commercialism aid in the development of Europe as global power culturally and economically during the modern period?

**chemistry**

2.) Substances A, B, and C can all act as oxidizing agents. In solution, A is green, B is red, and C is yellow. In the reactions in which they participate, they are reduced to A-, B-, and C- ions respectively, all of which are colorless. When a solution of A is mixed with one ...

**chemistry**

2.) Substances A, B, and C can all act as oxidizing agents. In solution, A is green, B is red, and C is yellow. In the reactions in which they participate, they are reduced to A-, B-, and C- ions respectively, all of which are colorless. When a solution of A is mixed with one ...

**calculus**

The antiderivative of arctan(4t)dt by integration of parts.

**physics**

342m/s

**english**

What are some product that are essential to your quality of life besides cell phones and ipod

**chemistry**

The specific heat of the dilute NaCl solution formed during the neutralization of the HCl is about 2% less than the 4.184 J/k g assumed in the calculation for the molar heat of neutralization of the acid. How will this affect your final result for the heat of neutralization?

**geometry**

Width of label=height of can=8 cm Length of label=circumference of can=2*pi*radius or pi*diameter. Circumference=7*pi, this is the length of the label also.

**Advertising-HELP**

How about the KY ads? They're a little much.

**Physics**

A 20.0 g marble sliding to the right at 58.8 cm/s overtakes and collides elastically with a 10.0 g marble moving in the same direction at 14.7 cm/s. After the collision, the 10.0 g marble moves to the right at 73.5 cm/s. Find the velocity of the 20.0 g marble after the collision.

**chemistry**

The molar heat of solution of a substance is found to be +35.34 kJ/mol. The addition of 0.20 moles of this substance to 1.5 L water initially at 55. °C results in a temperature decrease. Assume the specific heat of the resulting solution to be equal to that of pure water. ...

**math**

This requires trig. The sine of an angle is the (opposite side)/(the hypotenuse.) So sin(38) = 36/x. x = 36/sin(38) You can type that in your calculator. Make sure your calculator is in degree mode.

**chemistry**

2.) A 48 g sample of water at 75 °C is mixed with 32 g water at 18 °C. Find the temperature of the mixture.

**Survey of Math 140**

sorry. you could try changing the 80 to 79 in the first part. I was debating with myself, which one to use.

**Survey of Math 140**

First calculate the number of days between March 8 and May 26. 24 days in March, 30 days in April, and 26 days in May. Add those together=80 days. 4000(1+.10)^(80/365)= 4084.44. This is how much you owe on May 26, before the $1300 payment. Then subtract 4084.44-1300. This is ...

**Math**

You may want to look up "unit circle" on google. There's an excellent picture with all the angles and their measures labeled.

**Math**

When you draw the angle in standard position, the ray will be in the second quadrant. Draw a line segment from the end of the ray down to the x-axis to make a triangle. The reference angle is pi/3. Along the horizontal part of the triangle write -1/2. Along the vertical part ...

**Math**

-1/2

**Math**

The reference angle for 8pi/3 is pi/3. 8pi/3 = 6pi/3 + 2pi/3 = 2pi+2pi/3 2pi/3 is in the second quadrant, where cosine is negative and cos(pi/3)=1/2 So the cos(8pi/3)= -cos(pi/3) = -1/2

**Math**

use the product rule: (first times der of second) + (second times der of first)

**math**

3*3+3=12

**algebra**

what's the question asking?

**Algebra II-Please check my solution**

You're right. I'm sorry. When I saw the missed step, I stopped looking at the rest of the work. You are correct.

**Algebra II-Please check my solution**

you're on the right track but when you tried to subtract the 2 eq you only subtracted the first term, but left the others' signs the same. It should look like this: 4x+6y=4 -4x+2y=28 now add the two eq together and redo the work you did before. if you have more ...

**Math**

The ground would be a height of zero. So set your equation equal to zero and solve. 0=-9.8t^2-10t+330 If you need more help, respond to this post.

**Math**

you can think of opposite as diagonally in this situation

**Math**

Opposite angle of a parallelogram are equal. Consecutive angles are supplementary. W must be opposite Y so it equals 65. Remember that supplementary angles means they add up to 180. You can figure out X and Z.

**math- check me**

no. First multiply both sides by 5y, giving you -3=-45y, then divide by -45 -3/-45 = y this reduces to 1/15

**6th grade math**

The only figure similar to a square is another square. If the side of the square is 5cm, then the area is length times width, which would be 5 * 5 since all sides of a square are equal. So what's 5 * 5?? And don't forget to write cm squared after.

**algebra 2**

First add 15 to both sides to get all terms on one side of the equal side and a zero on the other: a^2-8a+15=0 Then set up your parentheses. ( )( )=0 Now ask yourself, what two things multiplied together = a^2? a*a So put one of each in the first place in the parentheses. (a...

**alg readiness**

A mixed number looks something like 3 1/2, read "3 and one half." Writing that as addition would be 3 + 1/2. To write it as a single fraction, you need to change it into an improper fraction by multiplying the denominator (2) by the whole number (3) and then adding ...

**Math**

Not necessarily. Only if it's a rectangle. But a rectangle is a more specific parallelogram.

**algebra**

Try using parentheses and the / sign for division when you type your question. I can't really understand what's going on here.

**algebra**

I would imagine it would read the average of the two weights: (60+43)/2 = 103/2=51.5 pounds.

**math**

If you received a $10 reward, then you spent between $50 and $99.99 If you received a $20 reward, then you could have spent $100, $125, or $149.99. If your purchase is $98, then you'd be better off spending $2 more, so that you'll get another $10 gift card. That would ...

**Math Correct?**

Yes. Since all the angles of a square are 90 degrees, two of them will always add to 180 degrees, which is the definition of supplementary.

**alg**

Sorry, silly error... 5y=25 y=5 (1,5)

**alg**

(9x+5y)=34 (8x-2y)=-2 You need to eliminate a variable so first pick either x or y to eliminate. I'll choose y. To eliminate y from the equations, you need to multiply by numbers that will give you zero y when you add the equations together: 2(9x+5y)=34*2 5(8x-2y)=-2*5 18x...

**math**

out=-25+25=0

**college psychology**

it effects the temporal lobe of the cerebral cortex

**college psychology**

What areas of the brain are affected and how are they affected with sleep deprivation?

**algebra**

Well, what I wrote would be considered the appropriate work shown.

**algebra**

You really should write a linear equation: You're right on calculating the rate. It is 4. You can also call that the slope of the line. In y=mx+b form, y=4x+b Since you started at 11 in 2006, 11 is your y-intercept (b) y=4x+11 Again, since you started at 2006, 2011 is 5 ...

**algebra**

What exactly is the question? If you have to solve the inequality, then you would subtract 2.2 from both sides, leaving you with: x<2.3

**Calculus**

The Product Rule is: (First*Derivative of Second)+(Second*Derivative of First) In your case: First is (x^3-2x) and Second is (5x^2+2x) Try that and write back if you're still having trouble.

**Pre-Algebra**

Yes they are all correct.

**geometry**

Ratios are usually good to set up like this: 4x+7x+5x=64 in this case. 4x = the shortest side, 7x = the longest side, and 5x = the middle side. Then solve for x. 16x+64 x=4 Then plug 4 back in for x to see what the individual side lengths are. 4*4=16 for the shortest side.

**algebra**

Substitute 2 in the inequality and see if the sentence is true. 4(2)+8<12 8+8<12 16<12 False, so 2 is not a solution. Do it again with 0 and see what happens. If need more help write back.

**Discrete Math**

Domain is correct. Range is all real numbers except 5. Since 1/(1+x) can never be 0, the equation will never be 5. Write back if you still have questions.

**math**

This question does not make sense, given that 2/5 + 3/4 = more than 1. Is there more information to this question?

**math**

Let x = number of gallons of %5 milk 0.05x + 0.01(100) = 0.02(x+100) 0.05x + 1 = 0.02(x+100) 0.05x + 1 = 0.02x + 2 0.03x = 1 x = 33 and 1/3 Write back if you need more explanation

**8th Grade Algebra**

In a standard deck there are 13 hearts and 4 aces. However one the hearts is an ace. So we're talking 13+4=17 cards, but then subtract one (16) for the ace of hearts that would be repeated if counting the hearts and aces separately. So 16/52 is the probability. This can be...

**math**

A=P(1+r)^t A=amount of money at end P=amount of money to start r=interest rate as a decimal t=number of years 20000=P(1+.05)^5 20000=P(1.05^5) 20000/(1.05^5)=P $15670.52=P

**8th grade Algebra**

(5/100)*(5/100)=25/10000=0.0025 or .25%

**math**

The center of the rectangle is equidistant from each vertex. If you make the center of your circle the center of the rectangle, then the four vertices of the rectangle will be equidistant from the center of the circle as well, making each distance from the vertex of the ...

**math**

Substitute -12 in for x in the above equation and solve for y. 6y+5(-12)=15 6y-60=15 simplifying 6y=75 adding 60 to both sides y=12.5 dividing both side by 6. k=12.5

**Math**

A circular tablecloth is draped over a rectangular table so that the center of the cloth is directly above the center of the table. The table is 6 X(times) 2sqrt(3)feet, and the cloth has a radius of 2 feet. What is the area of the portion of the tablecloth covered by the cloth?

**Chemistry**

A buffer solution of pH=9.24 can be prepared by dissolving ammonia and ammonium chloride in water. How many moles of ammonium chloride must be added to 1.0 L of .50 M ammonia to prepare the buffer?

**Chemistry**

What is the [S^-2] in a saturated solution (.1 M) of H2S, in which the pH had been adjusted to 5.00 by the addition of NaOH? For H2S, Ka1= 1.1X10^-7 and Ka2=1.0X10^-14

**Chemistry**

if u add if you add 2.0 ml of 10.0 M HCl to 500 ml of a .10 M NH3, what is the pH of the resulting solution? for NH3, kb=1.8X10^-5

**ap chem**

.004

**Chemisrty**

what is the molality of a 0.075m of ethyl alcohol in water at 25 degrees celcius. Assume the density of the solution at such low concentration is equal to that of water at 25 degrees celcius, 0.997g/ml

**Math**

f(x)=-x

**business**

Research the VISA website. After reviewing of all the documents you can find on the web and in libraries, write a 3-page response to the following questions

**calculus, limits, l'hopital**

Thanks. I made a really stupid error. You've been very helpful in answering my calc questions. I really appreciate it.

**calculus, limits, l'hopital**

Find the limit as x->0 of (2-2cos(x))/(sin(5x)) Mathematically I got 2/5, but on the graph it appears to be 0.

**math**

is that 9 times q times t times 9 times p times t?

**math**

i don't get scale draings how do you work it out?

**Minds at work**

A person that has a sevre overreation to an intense emotion might be experiencing a a. galvanic skin response b. sympathetic rebound c. suppressed emotion d. parasympathetic rebound if you relearn a song that you heard as a child, your savings score for relearning the song ...

**Teacher's Aide: Helping Abused Children**

I don't mean to be mean on this end but that is a very rude thing to ask anyone. 1st off i'm newly married, 6 months pregnant, and this is not the only thing that i'm going to school for. i actually have a 91% in my class and this is the only test that i've had...

**Teacher's Aide: Helping Abused Children**

i for got to post my answers: 1) B 2) D 3) A 4) A 5) C 6) B 7) D 8) A 9) C 10)C

**Teacher's Aide: Helping Abused Children**

1. The Stubborn Child Law enacted by Massachusetts in 1646 permitted parents to A. use corporal punishment when children disobeyed them. B. keep children out of school if they were needed for family work purposes. C. institutionalize a child born with a physical or mental ...

**algebra**

Let x = the salary of the husband. So Lien earned x+1700. Lien's salary + her husband's = 42100 x + 1700 + x = 42100 2x + 1700 = 42100 2x = 40400 x = 20200 Lien's husband earned $20200, and Lien earned 1700 + 20200 = $23900.

**Math**

What are the directions? It's not clear what to do.

**calculus**

Set the denominator equal to zero and solve for x. 3x-14 = 0 3x=14 x=14/3 This is the x-coordinate of the vertical asymptote.