L.Bianchessi
Most popular questions and responses by L.Bianchessi
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
asked on February 27, 2012 
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
asked on February 26, 2012 
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) >
asked on February 8, 2012 
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+
asked on February 27, 2012 
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
asked on February 27, 2012 
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
asked on February 8, 2012 
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?
asked on March 12, 2012 
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+
asked on February 27, 2012 
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^
asked on February 27, 2012 
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...
asked on February 26, 2012 
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+
asked on February 27, 2012 
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^2/0.100x =1.8 X10^5 x=1.3X10^3 then do ph=log(1.3X103) ph=2.9 is this right?
asked on March 6, 2012 
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
asked on February 26, 2012 
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
asked on January 23, 2012 
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?
asked on January 22, 2012 
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^2/0.100x =1.8 X10^5 x=1.3X10^3 then do ph=log(1.3X103) ph=2.9 is this right?
asked on March 6, 2012 
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**???
asked on March 5, 2012 
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, PreCalc, 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
asked on December 22, 2011 
precalc!!!!!
find the point on the line y=2x1 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 (2x)^2 + (1(2x1))^2 What do I do now?
asked on March 9, 2012 
MaTH!!!
Let P(x,y) be a point on the curve y=16x^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(81/2x^2). Is that right? And perimeter= x+16x^2+
asked on March 9, 2012 
PreCalculus
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.
asked on March 11, 2012 
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.
asked on February 24, 2012 
PreCalculus Help, thanks:)
Find the domain of f(x) = 1/ (square root 2x^27x15) I tried setting 2x^27x15 greater or equal to zero but I don't know where to go from there to solve for my domain. Help please!:)
asked on March 11, 2012 
Help please..Physio!!:0
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 lifethreatening situation?
asked on July 29, 2012 
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
asked on July 23, 2012 
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?
asked on March 10, 2012 
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?
asked on March 10, 2012 
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?
asked on March 10, 2012 
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...
asked on March 5, 2012 
Physio 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 lifethreatening situation?
asked on July 31, 2012 
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?
asked on July 23, 2012 
precalc!!!!!
Let f(x)=3x4x^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.
asked on March 5, 2012 
precalc!!!!!
Let f(x)=3x4x^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.
asked on March 5, 2012 
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
asked on February 21, 2012 
PreCalculus
Find the maximum value, and where it occurs for eAch function. G(x)= (square root x^2+4x+12)
asked on March 11, 2012 
chem sig figs
How many significant figures are in 0.0? And how about 0.00?
asked on February 25, 2012 
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
asked on February 21, 2012 
algebra
Find the slope. (3,1/3) and (3+h, 1/(3+h)) I think I get 1/ 3(3+h) ???
asked on February 5, 2012

I absolutely need help!!Math:/
oh, okay that makes sense its like a conversion factor. Thank you!
posted on July 23, 2012 
Vessels..Logical question??
figured it out. but need help on my other question please!:)
posted on July 23, 2012 
Chemistry(Thank you for your help!)
Average rate of disappearance just means slope! So... (0.5350.268)M / 0520sec =5.13 X 10^4Ms^1 Tada!
posted on March 9, 2012 
math
160Angstrom
posted on March 5, 2012 
Maths
S=5
posted on March 5, 2012 
Chemistry
You could probably set up a proportion. so.... 0.160/x= 0.205/1.5ppm Solve for x.
posted on March 5, 2012 
chemistry
Cr+3, Na+, I2, F2 Oxidized lose electrons
posted on February 29, 2012 
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 
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 
Math
Well 1min =60 sec ... So 60 sec +25 sec= 85sec
posted on February 28, 2012 
math
2cm.... 2cm x 4cm x3cm=24cm^3
posted on February 28, 2012 
math
285 miles to travel between two cities
posted on February 28, 2012 
ALGEBRA
ExampleDifference of squares: (x^2 + 5x6) = (x+6)(x1) 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^2ab+b^2)
posted on February 28, 2012 
Chemistry(Please check, thank you!!)
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 
Chemistry(Please check, thank you!!)
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 
trig
Answer: (square root 125x^2 )/ 5x
posted on February 28, 2012 
trig
Is it set equal to anything?
posted on February 28, 2012 
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 
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 
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 
Math pleez help
Is the 5 an exponent?
posted on February 28, 2012 
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 
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 
Finance
The cost equity. Because... Cost debt+ cost equity= WACC
posted on February 27, 2012 
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 xaxis. Then go up 2
posted on February 27, 2012 
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 (50)^2 +(21)^2 D=radical 26
posted on February 27, 2012 
Algebra
Do you mean ax^2+ bx+c=0 ??
posted on February 27, 2012 
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 
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 
chemistry
You would need the chemical formula for plant food to see what it produces as products.
posted on February 26, 2012 
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 
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 
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 
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 
Math/Trig
WELL FOR SIN AND AND CSC YOU KNOW THAT THE INTERVAL HAS TO BE BETWEEN 0
posted on February 26, 2012 
Chemistry
So you get 0.01304 mol HCL. YOU GET 0.483GRAMS OF CALCIUM HYDROXIDE.
posted on February 26, 2012 
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 
Chemistry
Yes.
posted on February 26, 2012 
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 7.78X103. What do you mean add to ka expression? I keep getting 1.35 now.
posted on February 26, 2012 
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 
Maths
I plugged in 3x72=___ (set them equal to 420,660,780,1020) Answer:44,124,164,244,284 degrees
posted on February 26, 2012 
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 
Maths
44&124degrees
posted on February 26, 2012 
Maths
Well I haven't done trig in a long time but u believe... You divide the 2 to each side to get Cos(3x72)=1/2 Then do the inverse to both sides to get rid of the cos and end with 3x72=60 degrees So x= 44 degrees Cosine is positive in quad1&4 So 44degrees
posted on February 26, 2012 
college algebra
Oh and the answer would be y=1/5x
posted on February 26, 2012 
college algebra
Oh, you just divide the negative to each side and get y=5x2. Then use yy1=m(xx1) y(2)=1/5(x10) Then solve.
posted on February 26, 2012 
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 
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 
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 
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 
math
use permutations and combinations on these types of problems.
posted on February 24, 2012 
math
Each person can stand 4 different ways I believe So I'm thinking 16 different ways all together.
posted on February 24, 2012 
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 
Chemistry 101
Delta T= (95Joules) / [ (16g Au) X (0.128 J/g C)] Change of temp= 46Degree celcius
posted on February 24, 2012 
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 
Chemistry
I'm thinking c,b,a?
posted on February 8, 2012 
algebra
8less than or equal to x less than or equal to 15
posted on February 5, 2012 
precalc
I got that same interval notation. Except I subtracted the 4/x^3 to the other side and ended up with (x+2)(x2)/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 
maths
15 I believe
posted on February 5, 2012 
ChemB
How do you know what number goes on the top and bottom for the disintegration?
posted on January 23, 2012 
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 
algebra
Solve for y. y(5)=3(x(2)) So y+5=3x6 Y=3x11 Basically you are now in Y=mx+b form
posted on January 23, 2012