L.Bianchessi

Most popular questions and responses by L.Bianchessi
1. Chemistry

Find the pH of each mixture of acids. 0.115 M HBr and O.125 M HCHO2. I TRIED DOING THIS PROBLEM THE SAME WAY AS THE ONE BEFORE BUT IT DIDN'T WORK. THE PH SHOULD BE 0.939. I did HBr as stronger acid and got concentration of H+ and put it into the ka

2. Chemistry

Find the pH of mixture of acids. 0.185 M in HCHO2 and 0.225 M in HC2H3O2 Im using an ice chart of weak acid and putting in strong acid in H+ initiAL concentration. I've done the problems many different ways but cannot seem to get the right answer help

3. Chemistry

Ranking equilibrium constants from largest to smallest according to an image?Ethene (C2H4) can be halogenated by the following reaction: C2H4 (g) + X2 (g) ->

4. Chemistry

Determine whether each cation is acidic or pH neutral. For those cations that are acidic, write an equation that shows how the cation acts as an acid. A) Sr+2 B) Mn+3 C) C5H5NH+ D) Li+

5. Chemistry

Find the pH of each mixture of acids. 0.020 M HBr and 0.015 M HClO4. They are both strong acids Si they dissociate completely. Si do I just add 0.020 and 0.015 and take the -log of that concentration to get the pH? Like thus.... 0.020+0.015=0.035

6. Chemistry

A chemist trying to synthesize a particular compound attempts two different synthesis reactions. The equilibrium constants for the two reactions are 23.3 and 2.2 X 10^4 at room temp. However, after 15minutes the chemist finds that the reaction with the

7. Chemistry

Calculate the percent ionizationof a 0.15 M benzoic acid solution in pure water Nd also in a solution containing 0.10M sodium benzoate. Why does the percent ionization differ significantly in the two solutions?

8. Chemistry

Determine whether each cation is acidic or pH neutral. For those cations that are acidic, write an equation that shows how the cation acts as an acid. A) Sr+2 B) Mn+3 C) C5H5NH+ D) Li+

9. Chemistry

Determine whether each anion is basic or neutral. For those that are basic, wrote an equation that shows how an anion acts as a base. (A) C7H5O2 ^- (B) I^- (C) NO3^- (D) F^-

10. Chemistry

The value of Kw increases with increasing temperature. Is the autoionization of water endothermic or exothermic? In thinking its both but I don't know how to explain it.hmm...

11. Chemistry

Determine whether each cation is acidic or pH neutral. For those cations that are acidic, write an equation that shows how the cation acts as an acid. A) Sr+2 B) Mn+3 C) C5H5NH+ D) Li+

12. Chemistry

find the ph of 0.100M NaC2H3O2 solution. do i just write an equation and solve for x NaC2H3O2 +H2O= Na2O + HC2H3O2- 0.100 0 0 so x^2/0.100-x =1.8 X10^-5 x=1.3X10^-3 then do ph=-log(1.3X10-3) ph=2.9 is this right?

13. Chemistry

Find the pH of mixture of acids. 0.185 M in HCHO2 and 0.225 M in HC2H3O2 Im using an ice chart of weak acid and putting in strong acid in H+ initiAL concentration. I've done the problems many different ways but cannot seem to get the right answer help

14. ChemB

The activity of carbon 14 in living tissue is 15.3 disintegrations per minute per gram of carbon. The limit for reliable determination of age is based on carbon 14 is .10 disintegration per min per gram of carbon. Calculate the max age of a sample that can

15. ChemB

measurements of carbon 14 taken from linen wrappings of the book of isaiah from the dead sea scrolls indicate that the scrolls contain 79.5% of the carbon 14 expected in living tissue. how old are these scrolls if the half life of carbon 14 is 5730 years?

16. Chemistry

find the ph of 0.100M NaC2H3O2 solution. do i just write an equation and solve for x NaC2H3O2 +H2O= Na2O + HC2H3O2- 0.100 0 0 so x^2/0.100-x =1.8 X10^-5 x=1.3X10^-3 then do ph=-log(1.3X10-3) ph=2.9 is this right?

17. Chemistry

A 0.035 M solution of a weak base has a pH of 10.88. What is the Kb for the acid? Where Di I even begun**???

18. I have a question concerning Spring Semester

Im a freshman in college and I just took Chem1, Trig, and Drama (12units). I am planning on taking Chem2, Pre-Calc, and Art1 for spring sem. (13units). I'm not sure if this is too much to take for next semester considering two five unit classes or should I

19. precalc!!!!!

find the point on the line y=2x-1 which is closest to the point (2,-1). I used distAnce formula and got D= (square root 5x^2 -4x +4) I did.... D=square root (2-x)^2 + (-1-(2x-1))^2 What do I do now?

20. MaTH!!!

Let P(x,y) be a point on the curve y=16-x^2 and let A be the point directly below P on the x axis. If O is the origin, find the area and the perimeter of triangle OAP as functions of x. I got Area=x(8-1/2x^2). Is that right? And perimeter= x+16-x^2+

21. Pre-Calculus

A town has a population which is growing linearly. In 1970 its population was 36,000 while in 1985 its population was 63,000. Find a formula for its population P(t), where t=0 corresponds to the year 1970.

22. Chemistry

This is probably easier then my making it but... Calculate the ph of a forming acid solution that contains 1.35% forming acid by mass. Assume a density of 1.01g/ml for the solution.

23. Pre-Calculus Help, thanks:)

Find the domain of f(x) = 1/ (square root 2x^2-7x-15) I tried setting 2x^2-7x-15 greater or equal to zero but I don't know where to go from there to solve for my domain. Help please!:)

If trypsin and chymotrypsin become activated within the pancreas and then are released in their active forms into the bloodstream, why would this represent a potentially life-threatening situation?

25. I absolutely need help!!Math:/

One liter of arterial blood at sea level contains approximately 3 mL of dissolved oxygen and 197 mL of oxygen bound to hemoglobin. If a normal individual has a cardiac output at rest of 5 liters per minute, how much oxygen is carried to the tissues per

26. precalc!!!!!

The point (5,-2) lies on the graph of y=f(x), and assume f^-1(x) exists. Find the corresponding point on eAch graph. A). Y=f^-1(x) I get (-5,2) B). Y=-f^-1(-x)+4 I get (5,2) C). Y=f^-1(x+2)+3 I get (-7,5) Did I get these right?

27. precalc!!!!!

The point (5,-2) lies on the graph of y=f(x), and assume f^-1(x) exists. Find the corresponding point on eAch graph. A). Y=f^-1(x) I get (-5,2) B). Y=-f^-1(-x)+4 I get (5,2) C). Y=f^-1(x+2)+3 I get (-7,5) Did I get these right?

28. precalc!!!!!

The point (5,-2) lies on the graph of y=f(x), and assume f^-1(x) exists. Find the corresponding point on eAch graph. A). Y=f^-1(x) I get (-5,2) B). Y=-f^-1(-x)+4 I get (5,2) C). Y=f^-1(x+2)+3 I get (-7,5) Did I get these right?

29. CHEMISTRY!!!!

Write two reactions for NaHCO3, reacting with water in one NaHCO3 is acting as acid the other as a base. Is 0.10M solution going to be acidic or basic? Explain. I write the two rxns but what do I do with then...

If trypsin and chymotrypsin become activated within the pancreas and then are released in their active forms into the bloodstream, why would this represent a potentially life-threatening situation?

31. Vessels..Logical question??

A classmate who has been standing still for several hours working on a laboratory experiment suddenly faints. Based on what was studied in this unit, what is the probable explanation?

32. precalc!!!!!

Let f(x)=3x-4x^2 Find f o f o f So... F(f(x)) I got a really big answer..... I think I might have done something wrong when doing the distributing algebraic work.

33. precalc!!!!!

Let f(x)=3x-4x^2 Find f o f o f So... F(f(x)) I got a really big answer..... I think I might have done something wrong when doing the distributing algebraic work.

34. Chemistry

According to the second law of thermodynmics..a) cold moves to hot B) low pressure moves to high pressure C) wet moves to dry D) dry moves to wet

35. Pre-Calculus

Find the maximum value, and where it occurs for eAch function. G(x)= (square root -x^2+4x+12)

36. chem sig figs

How many significant figures are in 0.0? And how about 0.00?

37. general chem

A burning log, light from flashlight, car in motion, are examples of what type of energy? 1)potential 2)thermal 3)kinetic 4)radiation

38. algebra

Find the slope. (3,1/3) and (3+h, 1/(3+h)) I think I get -1/ 3(3+h) ???

1. I absolutely need help!!Math:/

oh, okay that makes sense its like a conversion factor. Thank you!

posted on July 23, 2012
2. Vessels..Logical question??

figured it out. but need help on my other question please!:)

posted on July 23, 2012
3. Chemistry(Thank you for your help!)

Average rate of disappearance just means slope! So... (0.535-0.268)M / 0-520sec =5.13 X 10^-4Ms^-1 Tada!

posted on March 9, 2012
4. math

160Angstrom

posted on March 5, 2012
5. Maths

S=5

posted on March 5, 2012
6. Chemistry

You could probably set up a proportion. so.... 0.160/x= 0.205/1.5ppm Solve for x.

posted on March 5, 2012
7. chemistry

Cr+3, Na+, I2, F2 Oxidized- lose electrons

posted on February 29, 2012
8. Geometry

Volume =length x width x height You just multiply all three numbers to get what ever number m^3.

posted on February 28, 2012
9. Chemistry

Well since sulfuric acid is a strong acid it dissociate completely so you just do the -log(0.10) =pH

posted on February 28, 2012
10. Math

Well 1min =60 sec ... So 60 sec +25 sec= 85sec

posted on February 28, 2012
11. math

2cm.... 2cm x 4cm x3cm=24cm^3

posted on February 28, 2012
12. math

285 miles to travel between two cities

posted on February 28, 2012
13. ALGEBRA

Example--Difference of squares: (x^2 + 5x-6) = (x+6)(x-1) 1. Write an x in both parenthesis 2. Find factors of 6. (6x1 or 3x2) 3. The inner (6x) plus the outer (-1x) should equal the middle term 5x Or you could foil. Trinomial: (a+b)(a^2-ab+b^2)

posted on February 28, 2012

The ice bath one would take longer because it takes more energy for the solution in the flask to form products thus, the activation energy is higher making the reactants need energy so it is endothermic.

posted on February 28, 2012

That's true but you should include how the temperature affected the rate and which way the equilibrium shifted and how the color change tells you which way it shifted. When you heat the test tube the solution turned a dark purple/blue color. And when you

posted on February 28, 2012
16. trig

Answer: (square root 1-25x^2 )/ 5x

posted on February 28, 2012
17. trig

Is it set equal to anything?

posted on February 28, 2012
18. chemistry

No it would not. You convert 536.8 g to ml by using the density. You get 753 so no you cannot fit it into a 750 ml flask.

posted on February 28, 2012
19. Algebra helpp i am going to fail

Well you use the area of a square formula. Do. You do (3x+2)^2=Area Get it?

posted on February 28, 2012
20. Math

Well if your cheap calculator has a exponent. You could do 2.72^-4.7 You get 0.0090683057 It's pretty close!

posted on February 28, 2012
21. Math pleez help

Is the 5 an exponent?

posted on February 28, 2012
22. math/cal/trig solve for t

Cos inverse of 1/4 =2t So do cos inverse of 1/4=75.52... So... 75.52...= 2t Solve for t. T=37.76..

posted on February 28, 2012
23. Chemistry

Well... You know that KOH is a strong base... So it ionizes completely. KOH----> K+ +OH- So you need the molarity of KOH... So.. 1.100g/.5500 L x 1mol/56.11g KOH = 0.0356 M KOH So since KOH is strong... Concentration KOH, K+, and OH- = 0.0356M

posted on February 27, 2012
24. Finance

The cost equity. Because... Cost debt+ cost equity= WACC

posted on February 27, 2012
25. maths

Well you subtract the 16 to get your equation equal to one. Do x^2/16 + y^2/4=1 Your center is 0,0 Your eclipse would be horizontal. Do when graphing put a point at (0,0) then go 4 spaces in the negative and positive direction on the x-axis. Then go up 2

posted on February 27, 2012
26. maths

Well we can graph the points and form a triangle. We can then find the distance between each point(side). And if two sides have the same distance we know that the triangle is isosceles. Distance between AC: D=square root of (5-0)^2 +(2-1)^2 D=radical 26

posted on February 27, 2012
27. Algebra

Do you mean ax^2+ bx+c=0 ??

posted on February 27, 2012
28. chemistry

The acid on the left has a conjugate base on the right. H20 is acting as base, and H3O+ conjugate acid. It's pretty much the opposite.

posted on February 26, 2012
29. chemistry

You would add H2O to the acid and determine the products from a double reaction. The acid who gives the H+ up is the acid and the one who accepts it is the base. You look over at the products and those are called the conjugates. Do for example... 1) HSO4-

posted on February 26, 2012
30. chemistry

You would need the chemical formula for plant food to see what it produces as products.

posted on February 26, 2012
31. chemistry

Na+4 doesn't exist because sodium can only give away one electron because that's all it has. But maybe you are trying to say... Na3PO4---> 3Na^+ + PO4^-3

posted on February 26, 2012
32. Chemistry

Oh okay yeah I didn't add the 5.77x10^-3 to the weaker acid. So I determine concentration of stronger acid then put that H concentration into the weaker acid then I determine the concentration of the H of CH3COOH and get 7.02x10^-4 and add the H+

posted on February 26, 2012
33. Chemistry

you would do a conversion factor. 50g of H2SO4 x 1mol sulfuric acid/ molar mass of sulfuric acid x grams of H2/ 1mol H2 You get grams of H2. Get it?

posted on February 26, 2012
34. Math/Trig

YOU COULD SEE THE GRAPH BY GOING TO GOOGLE AND ENTERING IN WOLFRAM ALPHA A WEBSITE AND ENTER IN THE EQUATION. THEY USUALLY WILL GRAPH IT FOR YOU BUT YOU NEED TO DETERMINE THE PERIOD, AND ETC. STUFF FOR YOUR GRAPH.

posted on February 26, 2012
35. Math/Trig

WELL FOR SIN AND AND CSC YOU KNOW THAT THE INTERVAL HAS TO BE BETWEEN 0

posted on February 26, 2012
36. Chemistry

So you get 0.01304 mol HCL. YOU GET 0.483GRAMS OF CALCIUM HYDROXIDE.

posted on February 26, 2012
37. Chemistry

Determine your moles of HCl. Then use your equation to convert moles of HCl to moles of Ca(OH)2 then to grams of the calcium hydroxide. The ratio would be 2Mol HCL to 1mol of Ca(OH)2

posted on February 26, 2012
38. Chemistry

Yes.

posted on February 26, 2012
39. Chemistry

I got concentration of HCOOH rxn to be 5.77X10^-3. And the CH3COOH rxn to have concentration of 2.01X10^-3. I added those together to get 7.78X10-3. What do you mean add to ka expression? I keep getting 1.35 now.

posted on February 26, 2012
40. Chemistry

Oh, okay so increasing the kw makes the reaction produce more OH- and H+ so energy must be increasing on the reacting side to produce a endothermic reaction meaning energy is being absorbed to obtain a high temperature for the kw. Ahh...I get it! Thank

posted on February 26, 2012
41. Maths

I plugged in 3x-72=___ (set them equal to 420,660,780,1020) Answer:44,124,164,244,284 degrees

posted on February 26, 2012
42. Chemistry

It you cannot determine the concentration of the mixture by forming a double replacement became you form products that are the same as the reacting because you are mixing two acids.

posted on February 26, 2012
43. Maths

44&124degrees

posted on February 26, 2012
44. Maths

Well I haven't done trig in a long time but u believe... You divide the 2 to each side to get Cos(3x-72)=1/2 Then do the inverse to both sides to get rid of the cos and end with 3x-72=60 degrees So x= 44 degrees Cosine is positive in quad1&4 So 44degrees

posted on February 26, 2012
45. college algebra

Oh and the answer would be y=-1/5x

posted on February 26, 2012
46. college algebra

Oh, you just divide the negative to each side and get y=5x-2. Then use y-y1=m(x-x1) y-(-2)=-1/5(x-10) Then solve.

posted on February 26, 2012
47. Chemistry

I just wrote mine in terms of the concentration of the thiosulfate. Pretty much I isolated the variable I was trying to find. :) same thing though!

posted on February 26, 2012
48. college algebra

Solve for y for the given equations. Putting it in y=mx+b form. Then do the negative reciprocal of the slope from the given equation. After that use the point slope formula to calculate the new equation using the given point and your new slope. Do you get

posted on February 26, 2012
49. Chemistry

Yes, exactly! Since we are diluting we can use M1V1=M2V2. So Concentration of thiosulfate X Amt.(volume) of added thiosulfate = (75ml)total volume X the Concentration of the new concentration of thiosulfate in the flask(what you are trying to find) The

posted on February 26, 2012
50. Chemistry

I did this same experiment a couple weeks ago. We are measuring the amount of time it takes for the thiosulfate to run out. So to calculate the concentration of the thiosulfate ion. You can multiply the milliliters of thiosulfate in whatever trail you are

posted on February 26, 2012
51. math

use permutations and combinations on these types of problems.

posted on February 24, 2012
52. math

Each person can stand 4 different ways I believe So I'm thinking 16 different ways all together.

posted on February 24, 2012
53. Chemistry

I think I made a mistake.... 1.35g/100g solution=0.0135grams 0.0135g/1.01g=0.01337ml Then... 1.35g/46.03g CH2O2= 0.0293mols Then... 0.0293mol/ 1.337X10^-5 = 2.19X10^3 M pH= -log[H+] PH=-log(2.19X10^3) But I get a negative ph.

posted on February 24, 2012
54. Chemistry 101

Delta T= (95Joules) / [ (16g Au) X (0.128 J/g C)] Change of temp= 46Degree celcius

posted on February 24, 2012
55. chemistryhelp

Usually the salt is contained in what they refer to as a salt bridge. Connecting the electrodes of the experimented ions.

posted on February 24, 2012
56. Chemistry

I'm thinking c,b,a?

posted on February 8, 2012
57. algebra

8less than or equal to x less than or equal to 15

posted on February 5, 2012
58. precalc

I got that same interval notation. Except I subtracted the 4/x^3 to the other side and ended up with (x+2)(x-2)/x^3 less than or equal to 0. Then I drew one of those. Line grAphs Nd put circles at -2,2, and an undefined at 0. Then figured out where the x's

posted on February 5, 2012
59. maths

15 I believe

posted on February 5, 2012
60. ChemB

How do you know what number goes on the top and bottom for the disintegration?

posted on January 23, 2012
61. ChemB

Oh, okay. Do I always use that equation for any order rxn involving time? How about the units, would it be yrs^-1 or just years?

posted on January 23, 2012
62. algebra

Solve for y. y-(-5)=-3(x-(-2)) So y+5=-3x-6 Y=-3x-11 Basically you are now in Y=mx+b form

posted on January 23, 2012