Search: Calculate the pH of a 0.21 M CoCl3 solution. The Ka value for Co(H2O)63+ is 1.0 10-5.

Number of results: 33,033

college chem
To solve this, you require the Henderson-Hasselbach equation: pH = pKa + log(conc.base/conc. acid) You have pH and pKa, so plug in the numbers, and solve for the ratio of Base/acid. With some algebra, you can then figure out the volume amounts of each species.
Tuesday, March 23, 2010 at 11:54pm by Chris

Chemistry
E = hf. You have h and frequency. Calculate E (in Joules) for the transition. I think the easiest way to go about this is to calculate E for the energy levels of the H atom. It's a little work. E = 2.180 x 10^-18/N^2. Now substitute 1 for N and calculate E. Substitute 2 ...
Sunday, September 21, 2008 at 9:13pm by DrBob222

Quantitative Analysis
The dibasic compound B (pKb1 = 4.00, pKb2 = 8.00) was titrated with 1.00 M HCl. The initial solution of B was 0.100 M and had a volume of 100.0 mL. Find the pH at the following volumes of acid added and make a graph of pH versus Va; Va=0, 1, 5, 9, 10, 11, 15, 19, 20, and 22mL.
Wednesday, November 14, 2012 at 12:21pm by Missy

Chemistry
The base and acid are exactly neutralized; the pH is determined solely by the hydrolysis of the salt. (NH4Cl) = 50 mmols/200 mL = 0.25M. ......NH4^+ + H2O..> NH3 + H3O^+ I.....0.25.............0......0 C......-x..............x......x E.....0.25-x...........x......x Ka ...
Thursday, May 2, 2013 at 5:46pm by DrBob222

Chem 111
A solution is prepared by mixing 499 mL of 0.19 M Tris·Base and 592 mL of 0.37 M Tris·Acid. What is the pH of this solution? [Ka(Tris·Acid) = 8.5 × 10-9] Round your answer to two places past the decimal. I can do basic pH questions but I am at a loss...
Sunday, March 25, 2012 at 7:50pm by Brittany

chem.
a. the concentraion of Hion is 10^-6 pH then is defined as - log10 (10^-6)=6 b. find [H] from [H][OH]=10^-14 then conc H= 10^-14 / 10^-3 =10^-11 then find pH
Friday, December 18, 2009 at 12:40pm by bobpursley

Chemistry
q1. The label on an antacid remedy states that each tablet contains 750 mg of aluminum hydroxide. Calculate the volume of stomach acid, 0.10 mol/L HCl(aq), which can be nuetralized by one antacid tablet. Q2. Compare equivalence point to endpoint q1. The label on an antacid ...
Friday, September 22, 2006 at 5:04pm by Brittany Rusk

ALGEBRA
3 + x(12*4) - 24 if that is the problem then, 3 + 48x - 24 48x - 21 48x = 21 x = 21/48 x = 7/16 you can only combine 'like terms' x terms can only be added to other x terms, constant terms can only be added to other constant terms. do you understand?
Friday, January 21, 2011 at 2:12pm by helper

Geometry
#2. Draw the trapezoid. The ends are two triangles with bases x and 21-x (why?) If the height is h, x^2+h^2 = 10^2 (20-x)^2 + h^2 = 17^2 equating the two expressions for h^2, we have 17^2 - (21-x)^2 = 10^2 - x^2 Now you can solve for x, and then h. The area is then (30+9)/2 * h
Tuesday, February 12, 2013 at 5:53pm by Steve

Science math
Can no one help me? I posted a question earlier I don't need answer I need to understand what I did wrong my thinking is that if I have a 2:1 ratio And my total is 99 that if I divide by 3 then I can get the amounts 33x2 is 66, then 33x1 is 33 so it would be 66:33. I used ...
Thursday, October 18, 2012 at 6:52pm by Maria

Math
how do i minimize this function. 21L + (2600/L) Set the derivative equal to zero and solve for L. 21 - 2600/L^2 = 0 2600 = 21 L^2 There will be positive and negative solutions for L. You can use the second derivative test or direct calculation to see which gives a minimum.
Friday, November 24, 2006 at 3:50pm by David

math
4(x-5)+2+x=3 4x - 20 + 2 + x = 3 5x = 3 + 20 - 2 5x = 21 x = 21/5 x = 4.2
Monday, July 18, 2011 at 4:16pm by Ms. Sue

math
8 3/8 - 6 1/4 = 2 1/8 5 9/24 - 2 16/24 = 129/24 - 64/24 = ? 2 2/7 - 1 1/3 = 2 6/21 - 1 7/21 = ?
Sunday, September 19, 2010 at 10:33am by PsyDAG

MATH
(1 * 4) + 1 = 5 (5 * 4) + 1 = 21 (21 * 4) + 1 = 85 (85 * 4) + 1 = 341 (341 * 4) + 1 = 1,365
Tuesday, September 1, 2009 at 10:31pm by Ms. Sue

chemistry (confirmation)
a. Some solid must be present but the concn does not change. b. yes. a has a pH of 2, b has a pH of 10, c has a pH of 11, and d has a pH of 1 so C is the most basic. Here are a couple of sites for hydrolysis of salts. http://www.science.uwaterloo.ca/~cchieh/cact/c123/salts....
Sunday, July 20, 2008 at 12:52pm by DrBob222

chemistry
Run # Volume NaOH used (mL) 1 4.1 2 4.3 3 2.8 Concentraion of NaOH: 0.113 M pH of acid: 2.84 the questions are: #moles of NaOH: ? initial acid concentration: ? Determine the Ka and pka of the weak acid: ? So here is what I did: Shaked for several minutes about 1 g of the acid ...
Sunday, July 15, 2012 at 7:53pm by fenerbahce

Chem
HA(aq)+ H2O (l) <-> H3O+(aq)+ A¯ (aq) Given the reaction above, which of the following will cause an increase in the pH of an equilibrium mixture? Give all answers which apply. A) add KA B) add HA C) remove A¯ D) remove HA E) none of these will affect ...
Wednesday, February 9, 2011 at 9:35am by Michael

math
Okay, I have to get off the computer now, but I hope this which I figured so far will help you find the answer: I multiplied 16 20/21 and 28 3/7. I got the fraction 212532 over 21. Next, you subtract 4 13/25 from 212532 over 21, I think. Once you've done that, add 8 2/47, ...
Friday, August 24, 2007 at 10:40pm by brie

Math
1. I get A = 120.9 Even if it were a rectangle 25x11, the area would only be 275. s = 58/2 = 29 A = sqrt(29*7*4*18) 2. P = 2(27+21) = 96 A = 27*21 = 567 Am I reading the wrong numbers here? How did you arrive at your first two answers?
Thursday, January 19, 2012 at 5:22pm by Steve

physics
The punter himself does not accelerate. The football does. So does his foot, but not as much as the ball does. If his own center of mass accelerated to 8 m/s in 0.21 seconds, we would be a world class sprinter. The momentum change of the football, 8 m/s * 0.50 kg = 4.0 kg m/s ...
Sunday, November 20, 2011 at 10:05pm by drwls

maths
A Toy is in the form of a hemisphere surmounted by a right circular cone of the same base radius as that of the hemisphere .If the radius of base of the cone is 21 cm and its volume is 2/3 of the volume of hemisphere calculate the height of cine and surface area of the toy.
Tuesday, December 4, 2012 at 6:35am by simran

math
To make the numbers, we need to know each of the properties. We now know that there are 7 numbers. Mode is the number with the most occurrence. For example, in the set {18,21,21,22,25,26,29}, 21 is the mode. Median is the middle number, when the numbers are sorted in sequence...
Tuesday, January 26, 2010 at 7:36pm by MathMate

Chemistry
I need to calculate the molecular mass of ehtylene glycol based on the freezing point depression. The teacher said that for glycol i=1 and to use the equation m=delta T / Kf X i Kf = -1.86C/m so I did -2.5C / -1.86 X 1 = 1.344 I know that 1.344 can't be the weight for ...
Tuesday, February 21, 2012 at 2:05pm by Hannah

Chemistry
NaN3 is used in some automobile air bags. The impact of a collision triggers the decomposition of NaN3 as follows: 2NaN3(s) to 2Na(s) + 3N2(g). The nitrogen gas produced quickly inflates the air bag between the driver and the windshield. Calculate the volume of N2 generated at...
Friday, August 6, 2010 at 8:07am by HaldriecH

physics
a. hmax = ho + (Vf^2-Vo^2 / 2g. hmax=1.3 +(0-(20.1)^2 / -19.6=21.9 m. b. Tr = Vf-Vo) / g, Tr = (0-20.1) / -9.8 = 2.05 s. = Rise time or time to reach max ht. h = Vo*t + 0.5g*t^2 = 21.9 m. 0 + 4.9t^2 = 21.9, t^2 = 4.47, Tf = 2.11 s.Time to fall to ground. Tr + Tf = 2.05 + 2.11...
Tuesday, January 24, 2012 at 11:46am by Henry

chemistry
assume all of the ionized aspirin remains in the buffer solution and all of the un-ionized aspirin goes into to the ethyl acetate, what is the molarity of the aspirin in the ethyl acetate at pH 2 and pH 8? what equation would ou use for this?
Wednesday, April 3, 2013 at 8:31pm by kelly

Chem
The problem here, Lena, is that [pH][pOH]=1 x 10^-14 is not true. Two errors. pH + pOH = pKw = 14 which is the log form. If you wish to use the regular form it is or (H^+)(OH^-)=Kw = 1 x 10^-14 You mixed the two.
Monday, July 27, 2009 at 1:32am by DrGog222

Chemistry
NH3 + HOH ==> NH4^+ + OH^- Write Kb expression. (NH4^+) = x molar (OH^-) = x molar (NH3) = (1 - x) molar Solve for x which = (OH^-) then pOH = - log(OH^-) and pH + pOH = pKw = 14 Solve for pH. Post your work if you need additional help.
Friday, November 23, 2007 at 9:15pm by DrBob222

Math
Calculate the monthly finance charge for the following credit card transaction. Assume that it takes 10 days for a payment to be received and recorded and that the month is 30 days long. Assume 365 days in a year. (Round your answer to the nearest cent.) $3,000 balance, 21% ...
Sunday, August 5, 2012 at 7:05pm by JC

ALGEBRA
Calculate the monthly finance charge for the following credit card transaction. Assume that it takes 10 days for a payment to be received and recorded and that the month is 30 days long. Assume 365 days in a year. (Round your answer to the nearest cent.) $3,000 balance, 21% ...
Friday, May 18, 2012 at 11:29pm by Monic

math
Calculate the monthly finance charge for the following credit card transaction. Assume that it takes 10 days for a payment to be received and recorded and that the month is 30 days long. Assume 365 days in a year. (Round your answer to the nearest cent.) $3,000 balance, 21% ...
Tuesday, August 23, 2011 at 4:56pm by apryl

Chemistry
"The sun emits UV radiation that can have serious health consequences. In particular, so-called UVB radiation is mostly absorbed by the ozone layer in the upper atmosphere (altitudes of 10 - 50 km), but the part that reaches the earth can cause DNA mutations. The highest ...
Thursday, September 13, 2012 at 11:19pm by Travis

biochemistry
if 4 volumes of 0.1M monobasic potassium phosphate, KH2PO4, are mixed with 2 volume of 0.1 M dibasic sodium phosphate, Na2HPO4, what will be the pH of the mixture? What if 4 volumes of 0.1 M KH2PO4 are mixed with 8 volumes of 0.1 M ethanolamine base(pka=9.44) what will be pH ...
Friday, January 21, 2011 at 7:32pm by dIrk

Accounting102
calculate ending inventory-weighted average:ending inventory 21,ooo units. Beginning Inv 12,000 units@ $3.00 first purchase15,ooo.oo Units@ $3.25 2nd " 26,000 unite @ $3.30 3rd " 28,000 " @ $ 3.40
Thursday, February 7, 2008 at 12:25am by Mary

Chemistry
No. CaCO3 = CaO + CO2 mols CaCO3 = 0.979 from the problem. Convert mols CaCO3 to mols CO2 using the coefficients in the balanced equation. That is 0.979 mols CaCO3 x (1 mol CO2/1 mol CaCO3) = 0.979 x 1/1 - 0.979 mols CO2. Then you may use PV = nRT and solve for V OR you can ...
Wednesday, April 25, 2012 at 8:58pm by DrBob222

Chemistry
HCl is a strong acid. So is HBr. They ionize 100%. (H^+) from HCl = 0.035 moles/L. That from HBr is 0.080 moles/L. Add together to find total moles/L, then pH = -log(H^+). To find pOH, remember pH + pOH = pKw = 14.
Saturday, July 23, 2011 at 10:53pm by DrBob222

Chemistry
HC2H3O2 + NaOH --> NaC2H3O2 + H2O? a. when the titration is only half over, what species are present in the reaction flask b. what can be said about the pH at this point when the titration is half over? c. what is the pH at the equivalence point of this titration? 7, &...
Monday, April 4, 2011 at 3:14pm by Anonymous

chemistry lab titration
so for 0mL added would it be k3 = [(HAsO4^-2)(OH^-)/(AsO4^-)] K3 = (x^2)/(0.1M of AsO4) pk3 = -log k3. then solve for x which would give you [OH^-] which you could use to find pOH and find pH by using pH + pOH = pKw??
Wednesday, April 7, 2010 at 5:55pm by tara

math same question as before with new questions to
Many of your equations are wrong. B = 21 - A C = 24 -(21 -A) = 3 + A D = 32 - (3 + A) = 29 - A E = 37 - (29 - A) = 8 + A F = 31 - (8 + A) = 23 - A G = 25 - (23 - A) = 2 + A G + A = 26 The last two equations can be solved for A, which is 12
Saturday, October 25, 2008 at 11:27pm by drwls

Chemistry
I don't get this at all. A beaker with 105mL of an acetic acid buffer with a pH of 5.00 is sitting on a bench top. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 8.40 mL of a 0.470 M HCl solution to the beaker. How much will the pH ...
Sunday, March 25, 2012 at 2:31pm by Amanda

science
which has a lower ph pure water that is hot or pure water that is cold? is it possible for water to be neutralbut have a ph less than or greater than 7.0? how readily an acid donates a hydrogen is a fuction of how well the acid is able to accomodate the resulting negative ...
Friday, May 14, 2010 at 8:24pm by sarah

Analytical Chemistry
HBr + NaOH ==> NaBr + H2O 1. First you need to calculate the volume of HBr required to reach the equivalence mols NaOH = M x L = 0.1M x 0.1L =- 0.01 mols HBr must be 0.01 to reach the equivalence point. Then M HBr = mols HBr/L HBr. Substitute to obtain 1M = 0.01/L and L...
Saturday, December 1, 2012 at 3:37pm by DrBob222

Chemistry
Exactly 100 mL of 0.14 M nitrous acid (HNO2) are titrated with a 0.14 M NaOH solution. Calculate the pH for the following. (a) the initial solution (b) the point at which 80 mL of the base has been added (c) the equivalence point (d) the point at which 105 mL of the base has ...
Saturday, March 17, 2012 at 12:33am by Tanya

College Algebra
Assuming the 25000 is invested when the child is born, and she attends college after 18 years, that gives n=1 t=18. Or other values, if compounded more frequently than annually. You want an interest rate so that after 21 years (including the 3 years of attending college), the ...
Wednesday, February 1, 2012 at 10:56pm by Steve

Chemistry
The pH at the half-way point of a monoprotic acid is just pKa. For a monoprotic base (C2H5NH2) it is pKa but remember they give you pKb in the problem so pKa = 14-pKb. The pH at the equivalence point of a monoprotic acid or monoprotic base is calculated from the hydrolysis of ...
Friday, June 1, 2012 at 5:13pm by DrBob222

chemistry
a. molarity is defined as # moles/L solution. To find # moles, grams/molar mass. b. Look at the formula. There are two OH ions per Ba(OH)2 molecules; therefore, the concn of OH must be twice the answer to a. c. pOH = -log(OH). You have the OH from part b. d. pH + pOH = 14. You...
Tuesday, November 17, 2009 at 3:52pm by DrBob222

chemistry
Thymol blue in its acid range is not a suitable indicator for the titration of HCl by NaOH(aq) . Suppose that a student uses thymol blue by mistake in the titration of Figure 17-9 in the textbook and that the indicator end point is taken to be pH=2.0. Approximately what ...
Thursday, April 14, 2011 at 8:17am by sk1227

Please Help CHEM
The first four are correct. lower pH is more acid. b. [H3O+]=log^-1 (9.5)=3.16E9 the antilog or log^-1 key might be the 10x key on your calculator. pOH=14-pH=14-9.5=4.5 [OH-]=antilog (4.5)=3.2E4 Notice [OH][H}= 1E14, which offers another way to solve it.
Tuesday, December 7, 2010 at 2:03pm by bobpursley

Chemistry
Question: Suppose you have 557 ml of 0.0300M HCL and you want to make up a solution of HCL that has a pH of 1.831. What is the maximum volume (in liters) that you can make of this solution? I know that you can get the concentration of HCL using the pH given, but how do you ...
Tuesday, March 3, 2009 at 10:05pm by eliz

AP CHEMISTRY
mol Ba(OH)2 = M x L = ??. (OH^-) from Ba(OH)2 is twice that. Add to the following. mol NaOH = M x L = ? (OH^-) = total mole OH^-/total L Then pOH = -log(OH^-) Substitute pOH in the following and solve for pH. pH + pOH = pKw = 14
Saturday, February 18, 2012 at 12:10pm by DrBob222

Chemistry
When a good indicator has been chosen, the pH at which the solution changes color is very close to the equivalience point of the titration. If this "point" for a particular titration occurs at pH x, a good indicator for the titration would be indicator. X indicator 0...
Tuesday, April 8, 2008 at 3:02pm by tia

Chemistry
millimoles CH3COOH = 60.0 x 0.1M = 6,00 mmoles. 30 mL x 0.200 M NaOH = 6.00 mmols NaOH. So at 30.00 mL you are at the equivalence point and the pH is determine by the hydrolysis of the salt, in this case, CH3COONa. The concn of the salt is 6.00 mmoles/(60+30)mL = 0.06667M. I&#...
Wednesday, October 19, 2011 at 10:47pm by DrBob222

math
Grade weight weighted-grade 65 16% 10.4 70 21% 14.7 61 21% 12.8 76 42% 31.9 The weighted score is the sum of the weighted grade (third column).
Sunday, June 3, 2012 at 1:39pm by MathMate

Jill
State the relationship of A to B (i.e. <, >, = or can't be determined). 1. Using a 0.05 M Ag+ titrant A.VEP in titration 25-mL of 0.01 M MgCl2 B.VEP in titrating 25-mL of 0.01 M AlCl3 2. A 25.0-mL solution contains 0.015 M NaCl and 0.010 M HCl A.VEP (Mohr) B....
Monday, February 20, 2012 at 6:33pm by Chemistry Homework Help

physics
an engine block of mass 275kg rest on a plane which is inclined at 13 degrees to the horizontal.if the plane can be tilted to a maximum angle of 21 degrees before the engine block slide due to its weight.calculate the minimum force parallel to the plane required to move the ...
Wednesday, October 6, 2010 at 6:16am by charles

chem
Weigh amount SA accurately. Titrate manually with a standard solution of NaOH and plot on a sheet of graph paper (pH on y axis and mL on x axis). (Use an indicator to tell when you have reached the equivalence point). Then read the pH at the half-way mark to the equivalence ...
Thursday, November 11, 2010 at 5:07pm by DrBob222

college - Environmental Economics
Subject for the question is from the subject Envoronmental Economics: For each set of parameter values: - Calculate the optimal time to extract the resource - How do you find transistion/switch point? - Calculate the Extraction path (Q0, Q1, etc.) - Calculate the MUC in each ...
Monday, October 27, 2008 at 2:03pm by Kimberly

TO MS SUE SCIENCE HELP
Volume = (27.8 -21.2) cm^3 mass = 22.4 g density = 22.4/(27.8-21.2) g/cm^3
Friday, December 14, 2012 at 10:11pm by Damon

Calculus
a*b = 147 147 = 3*7*7 So, the only choices for a*b are 3*49 49*3 7*21 21*7 1*147 147*1 You can figure which gives minimum a+3b
Tuesday, October 25, 2011 at 11:40pm by Steve

science
A 0.21 g of Sulfuris acid is dissolved completely in sufficient water to make 0.25 litre of final solution. Calculate the hydrogen ion concentration (in mol 1 -1) in this solution. Give your answer in scientific notation to an appropriate number of significant figures. ...
Tuesday, March 6, 2007 at 6:37am by Gemma

statistics
What is the third quartile, Q3, of the following distribution? 27, 18, 20, 21, 29, 33, 12, 14, 34, 10, 16, 21, 22, 24, 26 A. 24 B. 18 C. 27 D. 4 E. 31
Wednesday, April 20, 2011 at 5:26pm by mark

Math
A 10-gal aquarium is 3 in. higher than it is wide. Its length is 21 in, and its volume is 2730 in^3. What are the height and width of the aquarium? x(x+3)......x^2+3x 21(x^2+3x).... 21x^2+63x-2730..... I am stuck.....I think I am doing it wrong. I have the answers but I dont ...
Sunday, July 13, 2008 at 4:59pm by Aniya

bio chem
Explain how to prepare 1L of a buffer at pH 7.4 using 1M hypochlorous acid (Ka = 3.5 x 10-8) and a 1 M NaOH solution. Indicate the volume of hypochlorous acid and sodium hydroxide to use. pH = pKa + log ([A-]/[HA]) Ka= [H+][A-]/[HA] Molarity = moles/L moles = g/molecular weight
Tuesday, March 12, 2013 at 10:31am by Anonymous

chemistry
delta T = Kf*m Calculate m m = mols/kg solvent. calculate moles. moles = grams/molar mass calculate molar mass.
Tuesday, February 9, 2010 at 11:41pm by DrBob222

Chem - Titration
A 100.0-mL aliquot of 0.100 M diprotic acid H2A (pK1 = 4.00, pK2 = 8.00) was titrated with 1.00 m NaOH. Find the pH at the following volumes of base added and make a graph of pH versus Vb: Vb = 0, 1, 5, 9, 10, 11, 15, 19, 20, and 22 mL
Monday, January 23, 2012 at 3:49pm by Meg

chemistry
A 0.15M solution of weak triprotic acid is adjusted (base added) so that the pH is 9.27(you can assume minimal volume change). The triprotic acid(H3A) has the following acid ionization constants: Kal=1.0*e-3, ka2=1*e-8,ka3=1*e-12. which species given below is present in the ...
Friday, May 13, 2011 at 7:31pm by vivanh

geometry
2(x+y)=42 x+y=21 xy=54 x + 54/x = 21 x^2 - 21x + 54 = 0 (x-18)(x-3) = 0 x=18 y=3 or x=3,y=18 Either way, the rectangle is 3x18
Friday, October 28, 2011 at 4:40pm by Steve

Health Finance
Question Details Consider the following 2007 data for Newark General Hospital (in millions of dollars): Static Flexible Actual Budget Budget Results Revenues $4.7 $4.8 $4.5 Costs 4.1 4.1 4.2 Pro?ts 0.6 0.7 0.3 a. Calculate and interpret the pro?t variance. b. Calculate and ...
Thursday, January 26, 2012 at 10:05am by molamidi

chemistry
Please let me know if my answer to the following question is correct. Question: What is the concentration of a weak base if its Kb = 1.4 x 10-11 and its pH = 8.75? Answer: Converting pH to H^+ concentration using the formula H^+ = 10^-ph, therefore 10^-8.75 gives an H^+ ...
Tuesday, April 15, 2008 at 4:56pm by Abigail

economics
Young Saul, a budding mctaemhtiaian and printer, is making himself a fake ID. He needs it to say heâ€™s 21. The problem is heâ€™s not using a computer, but rather he has some symbols heâ€™s bought from the store, and thatâ...
Friday, March 23, 2012 at 10:43pm by GWPeAYsBnmh

Math: please check
Consider a bowl containing 36 different slips of paper. Ten of the slips of paper each contain one of 16) the digits from the set 0 through 9 and 26 slips each contain one of the 26 letters of the alphabet. If one slip is drawn at random, what is P(odd number or a consonant)? ...
Sunday, May 2, 2010 at 2:10am by Bart

Physics
A cannon ball is fired at 50 m/s at a 37 degree angle above the horizontal. Calculate the time the cannon ball in the air, calculate how high it rises and calculate how far from the cannon the ball lands? Answers: 6.14 s, 46.2 m, 245.2 m
Tuesday, November 13, 2012 at 10:00pm by Victoria

Chem
In photosynthesis, plants form glucose and oxygen from carbon dioxide and water. 6CO_2+6H_2O --> C_6H_12_O_6+6O_2 a) Calculate deltaH rxn at 15 degree C b) Calculate deltaS rxn at 15 c) Calculate deltaG rxn at 15 thanks!
Wednesday, April 7, 2010 at 10:43am by Beau

Pre Calculus 12
Last post for tonight, going to bed diameter is 30 m, so a=15 So, (recall the last question with the 18 and 19) the min value is going to be -15 , but we want it to be 1.5 above ground , (the x-axis) so we have to add 16.5 sofar we have y = 15 sin k(t + d) + 16.5 , t in ...
Wednesday, January 23, 2013 at 10:53pm by Reiny

Chemistry
You must recognize that this is a mixture of two weak acids; i.e., formic acid and acetic acid. I looked up Ka for both and used 1.77E-4 for Ka HCOOH and 1.8E-5 for Ka CH3COOH. Calculate the H^+ from the strong acid, then add the H^+ from the weak acid. Formic acid first since...
Sunday, February 26, 2012 at 2:27am by DrBob222

maths
1. Convert the ffl octal numbers into denary number a) 1527 b) 21 364 2. Convert the ffl denary numbers into binary numbers a) 578 b) 709 3. Calculate the follwing using the octal system. a) 704 + 147 b) 652 - 406 c) 657 * 4 d) 754/6 Thanks
Monday, February 26, 2007 at 10:58am by temise

Chemistry
This is what I'm doing .10M (.0122L)= .00122 moles of NaOH .00122/(.008+.0122)= .06039M I get 0.06040 M NaOH .10M (.008)= .0008 moles CH3COOH .0008-.00122=.00042 moles HCl unreacted .00042/(.008+.0122)=.020792M CH3COOH The HCl is not in excess and unreacted. The reaction ...
Monday, May 3, 2010 at 2:50pm by DrBob222

Chemistry
This is NOT a very good question because it doesn't specify what is meant by equal amounts. Is that equal amounts of mass, equal amounts of moles, or just what? If it is equal amounts of moles, then It will be pKa of acetic acid. pH = pKa + log(base)/(acid) If base = acid...
Tuesday, July 12, 2011 at 8:17pm by DrBob222

Algerba 1
1. 3 * 10^4 * 7 * 10^-4 7*3 = 21 10^4 * 10^-4 = 10^0 = 1 21 * 1 = 21 2.1 * 10^1 2. (5*10^4)^2= 25 * 10^8 = 2.5 * 10^9
Thursday, April 11, 2013 at 9:57pm by Knights

chemistry
the data is Vol. of NaOH added 0 1 2 3 4 5 10 15 20 21 22 23 24 25 26 27 28 29 30 35 40 45 50 pH 2.92 3.47 3.79 3.98 4.13 4.25 4.67 5.03 5.57 5.72 5.91 6.23 8.78 11.29 11.59 11.75 11.87 11.96 12.22 12.36 12.46 12.52 this is the data and this was given
Monday, January 14, 2013 at 8:33pm by lisa

Chemistry
A reaction is said to be diffusion controlled when it occurs as fast as the reactants diffuse through the solution. The following is an example of a diffusion controlled reaction. The rate constant for this reaction is 1.4x1011 M-1s-1 at 25oC and the reaction obeys the ...
Tuesday, May 19, 2009 at 11:59pm by Kevin

physics
On a spacecraft two engines fire for a time of 581 s. One gives the craft an acceleration in the x direction of ax = 5.21 m/s2, while the other produces an acceleration in the y direction of ay = 7.34 m/s2. At the end of the firing period, the craft has velocity components of ...
Sunday, September 9, 2012 at 5:24pm by Sharienia

World History
For questions 21- 30 you are given three items: a place, a person, and a thing. Choose True if all these are associated with one another, choose False if they are not: 21. Long March-Mao ZeDong-China True or False
Tuesday, September 18, 2007 at 12:16pm by Cody

Algebra
For questions 20-21, begin with the following equation: y = 8x^2 + 10x + 3 . 20) Find the axis of symmetry. > -5/8 21) Identify the vertex as a maximum or minimum. > minimum ___________________________________ Please tell me if these answers are correct or not
Sunday, June 10, 2007 at 7:02pm by Michael

statistics
Here is a hint for part a): Try a one-sample t-test. You will need to calculate mean and standard deviation to plug into the formula. Calculate, then determine the p-value from a t-table. The p-value is the actual level of the test statistic you calculate. I'll let you ...
Thursday, July 19, 2012 at 10:58am by MathGuru

Physics
Force F causes displacement d of a 20-Kg object starting from rest along a frictionless path. F= 10 N i + 50 N j + 15 N k and d= 10 m i + 60 m k A) Calculate the work done by the force. B) Calculate the angle between the vectors F and d. C) Calculate the final speed of the ...
Wednesday, April 22, 2009 at 10:40pm by Sandhya

Chemistry
If 12.50 grams of Pb(NO3)2 are reacted with 3.18 grams Nacl in a "typical double displacement" reaction, please calculate the following: a) What is the limiting reagent? b) what is the reagent in excess? c) Calculate the mass of the excess. d) Calculate the ...
Sunday, April 6, 2008 at 1:16pm by Larissa

chemistry
Convert 7.5 g HCl to mols. moles = grams/molar mass. Convert moles and volume to molarity. M = mols/L soln. HCl is a strong acid; i.e., it is ionized 100%; therefore, (H^+) of a solution of HCl = (HCl). Use (HCl) to convert to pH. pH = -log(H^+).
Sunday, February 27, 2011 at 12:53pm by DrBob222

chem 126
Phenolphthalein is a commonly used indicator that is colorless in the acidic form (pH < 8.3) and pink in the basic form (pH > 10.0). It is a weak acid with a pKa of 8.7. What is the ratio of the conjugate base concentration to the acid concentration, that is, [B...
Friday, March 15, 2013 at 9:32pm by carl

Chemistry
I just took a quick look and I'm glad I did. I think you are working it right. You see my last response gives a value of 0.05218 (it should be -0.05218); you may not have keyed in enough significant figures. Round -0.05218 to the right number of s.f. from your original ...
Tuesday, March 27, 2012 at 6:01pm by DrBob222

Chemistry
Zn(OH)2 ==> Zn^2+ + 2OH^- Ksp = 4.0E-17 = (Zn^+)(OH^-)^2 pH = 5.0; use pH + pOH = pKw = 14 to solve for pOH, then -log(OH^-) to solve for (OH^-). Substitute OH into Ksp expression and solve for Zn^2+. That is the solubility of Zn(OH)2.
Tuesday, April 16, 2013 at 11:53am by DrBob222

earth
The orbital period of any satellite derives from T = 2(Pi)sqrt(r^3/µ) where T = the period in seconds, 6(3600) = 21,600, r = the orbit radius in seconds and µ = the earth;s gravitational constant. Therefore, 21600 = 2(3.14)sqrt(r^3/1.407974x10^21) from which r = 55...
Sunday, October 2, 2011 at 9:34pm by tchrwill

College chemistry
You're making this much harder than it is. Don't be intimidated by chemistry. The difference is 7.4-6.4 = 1.0, right? To convert pH to H3O^+, use pH = -log(H3O^+) 7.4 = -log(H3O^+) and 6.4 = -log(H3O^+). Solve each for H3O^+ and subtract these two numbers to find how ...
Tuesday, April 30, 2013 at 3:38pm by DrBob222

Math (Check
Please see the last answer for the correction for 1. 2. is correct. 3. 20 1/9 - 14 7/15 = You need to find a common denominator. 45 is divisible by 9 and 15 20 1/9 - 14 7/15 = 20 5/45 - 14 21/45 Now we need to change the first number to get a fraction larger than 21/45 20 5/45...
Sunday, July 13, 2008 at 7:17pm by Ms. Sue

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