Monday
March 17, 2014

# Search: 14 carat gold has a purity of 58.3%. How many moles of gold are in 154 grams of 14 carat gold? Answer in

Number of results: 34,303

Chemistry
Read my instructions; part C. C. M original soln = moles/L soln = moles in original soln/0.1L = ? It's mols/L and you had 100 mL (0.1L) of the original solution.
Monday, March 12, 2012 at 8:26pm by DrBob222

chemistry
How to find moles given oxidation numbers and chemical formula? Trying to do my chemistry lab but i'm super duper stuck. please help me i'm gonna die. this is the part i'm stuck on: The overall charge on the complex, [Ni(en)(H2O)]^2+ * SO4^2- * H2O is zero; the charge on ...
Thursday, November 15, 2012 at 12:37am by dr bob's number one fan

math
(8,4) (14,7) (x, y) x - 14 = 14 - 8 x = 20 y -7 = 7 - 4 y = 10 (20,10)
Thursday, February 3, 2011 at 6:44pm by Damon

Chemisty
moles = grams/molar mass. Calculate moles. m = moles/kg solvent. Calculate m delta T = Kf*m Calculate delta T. The freezing point of the solvent, normally, is 0o C. The freezing poing depression constant for the solvent, H2O, is 1.86 o/m. You may have rewritten the problem, ...
Sunday, March 7, 2010 at 7:37pm by DrBob222

lottory maths
winning no. marchine no. 85-42-43-36-50 <> 5-74-35-24-23 83-58-43-21- 6 <> 56-33-38-46-73 69-18-59-49-35 <> 36- 9-47-71-78 14-40-88-76- 1 <> 5-32-62-20-27 48-39-37-71-53 <> 81-52-12- 6-14 29-63-80-57-37 <> 19-65-42-44-21 69- 2-68-35-31 <...
Sunday, July 3, 2011 at 1:19pm by Gen

chemistry
I agree with your answer to (a) of 10.74. I agree with b and c. For D, H2NNH2 + HNO3 ==> H2NNH3+^ + NO3^- You had 0.1 L x 0.1 M = 0.01 moles H2NNH2. You added 0.06 L x 0.2 M = 0.012 moles HNO3. You had an excess of 0.002 mols HNO3 (just has you have it). So there is an ...
Sunday, July 26, 2009 at 2:14am by DrBob222

college math
10. For questions 10-13, use the following data: 13 29 41 60 89 14 26 53 7 14 What is the arithmetic mean of the data? (Points: 5) 20 14 34.6 82 11. What is the range of the data? (Points: 5) 14 34.6 82 50 12. What is the variance of the data? (Points: 5) 231.04 616.64 685.16...
Monday, November 7, 2011 at 1:25pm by Anonymous

chemistry
1. Write the equation and balance it. CH4 + 2O2 ==> CO2 + 2H2O 2. You need not convert to moles if all of the components of a reaction are gases; i.e., the volumes are proportional to the coefficients in the equation. Therefore, 500 L O2 x (1 mole CH4/2 moles O2) = 500 L x...
Sunday, May 16, 2010 at 9:27pm by DrBob222

chemistry
Consider the following reaction. 4Fe + 3O2=2Fe2O3 a. How many moles of O2 are required to react completely with 29.8 mg of Fe? 4.00 x 10^-4 moles O2 b. How many grams Fe2O3, are produced from the complete reaction of 17.8 g of Fe? 25.4 g Fe2O3
Tuesday, February 14, 2012 at 10:29pm by krystal

chemistry
CaCO3(s)+2HCl(aq)-->CaCl2(aq)+H2O(l)+CO2 (g) How many grams of calcium chloride will be produced when 31g of calcium carbonate are combined with 11 g of HCl? I have 0.3097 moles of CaCO3 and 0.30169 moles of HCl...I get stuck at that point
Thursday, January 17, 2013 at 4:28pm by Jana

CHEMISTRY
A throat lozenge contains 5.0mg of menthol, which has the formula C10H20O. a. How many moles of menthol are in 5.0 mg of menthol? b. What is the mass in grams of 1.56 moles of menthol? a. I got 3.2 x 10^-5 mole is that correct? b. Not sure how to do this problem. I do know ...
Monday, July 1, 2013 at 11:36am by Tiffany Brooke

Java
I need help putting the following trace into pseudocode 1 public class testOperators 2 { 3 public static void main(String[] args) 4 { 5 int x; 6 int y = 12 7 double z = 13.0; 8 x = 14 9 System.out.println(“x + y + z = “ + (x + y +z)); 10 x += y; 11 y--; 12 z++; 13 z *= x; 14 ...
Saturday, January 31, 2009 at 3:35pm by SCCC

chemistry question check
consider the following chemical reaction: 2 H20 ---> 2H2 + O2 How many moles of H20 are required to form 1.8 L of O2 at a temperature of 315 K and a pressure of 0.957 atm? I got 0.066 moles. Correct? Nope. Do you have some reasoning that you followed you want to have ...
Thursday, March 29, 2007 at 9:04pm by Elisa

Chemistry
molarity is moles of solute per liter of solution: M = moles/L plug in the given values in the equation, therefore: M = 1.77 / 30.6 = 0.0578 M is it required to write the answer in correct number of significant figures? if not, i think 0.06 M is acceptable ; but if yes, it ...
Friday, October 29, 2010 at 3:28am by jai

Chemistry
1 N204(l) + 2 N2H4(l) --> 3 N2(g) + 4 H2O(g) If you start with: 5.0 x 10^4 hydrazine (N2H4) "in the tank": 1) How many moles of nitrogen can be created (assuming 100% yield)? 2) How many moles of water can be produced? 2) What mass of dinitrogen tetroxide (N2O4) is needed? ...
Tuesday, November 23, 2010 at 6:46pm by Lauren K.

Oceanography
Salinity is a measurement that indicates the amount of salts dissolved in water, usually on a w/w basis. Concentrations are commonly expressed as parts per thousand (ppt or 0/00). Normal seawater salinity is 34 parts per thousand, meaning that 1,000 grams of seawater contains ...
Wednesday, September 24, 2008 at 12:05am by Dr Russ

chemistry
solution The hydrogen ion concen.(H+),of the acid is 0.25moldm3 ie(H)=0.25 but ph=-log{H+} ie pH=-Log{0.25} =-log{2.5*10`} =-0.398+1=0.602 but pH+pOH=14 i.e 0.60+pOH=14 ^pOH=14-0.60 =13.40
Thursday, March 10, 2011 at 5:56am by peter onoriode

chem
Write the balanced equation. Convert CaCl2 to mols. #mols = M x L. Convert AgNO3 to mols. Determine the limiting reagent (from the moles that is easily done) but note that the reaction is not a 1:1 reaction. Convert moles AgCl to grams. Post your work if you need further ...
Monday, March 2, 2009 at 1:15pm by DrBob222

chem
CaSO4(s) ==> Ca^+2 + SO4^= Ksp = (Ca^+2)(SO4^=) I would calculate moles Ca^+2 and moles SO4^=, from an ICE chart you will know which is the limiting reagent and from there which is the common ion (that will be the one in excess). Then calculate the solubility and from there...
Thursday, April 23, 2009 at 5:39pm by DrBob222

chem
are 7.60 and 3.00 in moles? if it is, recall the formula relating moles (n) and volume (V), at a constant P and T: n1 / V1 = n2 / V2 plug in the given values to the equation: 7.60 mol/ 31.0 = (7.60 + 3) mol / V2 then solve for V2. hope this helps. :)
Friday, October 29, 2010 at 4:10am by jai

chemistry
1). 50 mL of 0.1 M NH3 + 50 mL of 0.1 M NH4NO3. (NH3) = 0.1 x (50/100) = 0.05 M. (NH4NO3) = 0.1 x (50/100) = 0.05 M in the buffer. 1)So we start with 10 mL 0.05 M buffer. We dilute NH3 and NH4NO3 with 6 mL water. The new concn (NH3) = 0.05 x (10/16) = ?? The new concn (NH4NO3...
Tuesday, April 14, 2009 at 6:15pm by DrBob222

Math
make a sketch label the man's distance from the post as x and the length of his shadow y by similar triangles and ratios 6/y = 15/(x+y) 15y = 6x + 6y 9y = 6x 3y = 2x 3dy/dt = 2dx/dt dy/dt = (2/3)(7) = 14/3 ft/s so the length of his shadow is lengthening at 14/3 ft/s but it is ...
Friday, November 2, 2012 at 1:06pm by Reiny

college chem
For A. Assume you have enough solution to contain 10.88 moles ethanol. Therefore, you will have 1 kg water (1,000 g). 10.88 moles x (46 g/mol) = 500.48 grams ethanol. Total mass of the solution is 1000 g + 500.48 = 1500.48 grams. % ethanol = (mass ethanol/mass soln)*100 % ...
Tuesday, March 9, 2010 at 11:11pm by DrBob222

algebra
let the integers be n-3, n-1, n+1, n+3 5(n-3 + n+1) = 4(n-1 + n+3)+14 5(2n-2) = 4(2n+2)+14 10n-10 = 8n+22 2n = 32 n=16 The numbers are 13,15,17,19 Check: 5(13+17) = 150 4(15+19)+14 = 150
Tuesday, July 17, 2012 at 1:51pm by Steve

CHEM 136
I can't do the entire titration for you. 1. mL acid x M acid = mL base x M base. 2. The secret to a,b,c,d, is in knowing where you are on the titration curve. a. Pure HNO2. Before any NzOH has been added. HNO2 ==> H^+ + NO2^- Ka = (H^+)(NO2^-)/(HNO2) Substitute into Ka ...
Tuesday, November 23, 2010 at 4:49pm by DrBob222

Algebra
Area of triangle = 1/2(height x base) The problem states that base is 8 cm greater than the height; therefore, base-8 = height. A = 1/2(b*h) 42 = 1/2(b*[b-8]) 84=(b^2-8b) rearrange to b^2 - 8b -84 factor to (b+8)(b-14) Therefore, b = -8 cm which makes no sense and b = +14 cm ...
Wednesday, January 14, 2009 at 11:33am by DrBob222

AP Chemistry
My objective is to find the molar mass of a gas. Is this the correct balanced equation for magnesium ribbon reacting with hydrochloric acid to form hydrogen gas? 2Mg (s) + 2HCL (l) ----> H2 (g) + 2MgCl (aq) Also, I'm required to find the mass of the magnesium ribbon in ...
Sunday, September 23, 2007 at 1:08pm by Jake

Chemistry
CH3COOH + NaOH ==> CH3COONa + H2O So the pH at the equivalence point will be determined by the hydrolysis of the salt. CH3COO^- + HOH ==> CH3COOH + OH^- Kb = (KwKa) = (OH^-)(CH3COOH)/(CH3COO^-) Set up an ICE chart, substitute into the Kb expression, and solve for x, then...
Wednesday, December 15, 2010 at 5:02pm by DrBob222

Math
The answer to your question is 34. You have to use order of operations. first do 8x6 which is 48, then 7x2 which is 14 so subtract 48 and 14.
Monday, November 5, 2007 at 5:53pm by Susie

algebra
Janet invested \$6,000, part at 14% and part at 13%. IF the total interest at the end of year is \$820, how much did she invest at 14%?
Thursday, January 10, 2008 at 1:49pm by bjb

Math (pre-calculus)
Okay: a sub1=2 a sub2= 3(2)-1=5 a sub3= 3(5)-1=14 a sub4= 3(14)-1=41 a sub5= 3(41)-1=122 I think that's it! Thanks so much again!
Sunday, November 2, 2008 at 12:57pm by Angellove

Algebra
212 - 198 = 14 14 / 8 = 1.75 -- so he lost an average of 1.75 pounds per week. That's about 0.8% of his original weight.
Monday, June 29, 2009 at 10:01pm by Ms. Sue

Math
The easier way is to convert the fractions to decimals and run it through a calculator. 14 1/4 = 14.25 12 3/8 = 12.375
Friday, July 31, 2009 at 9:22pm by Ms. Sue

Math Stil don't know how to do this problem :(
Another way to approach this problem: 1. Find the common denominator. 2. Change 15 1/6 to 14 14/12 Take it from there.
Sunday, October 17, 2010 at 9:45pm by Ms. Sue

physics
C = 6.28*r = 18Ft. r = 2.93Ft. A=3.14*r^2 = 3.14 * (2.93)^2 = 27Ft^2. Check your 4-8-11,11:24am post for solution to interest prob.
Sunday, April 10, 2011 at 4:41pm by Henry

Physic
the run the same distance. distancetortiose= .14*time distancehard=15*.14(t-2) set the distances equal, and solve for t, which is time in minutes.
Thursday, September 1, 2011 at 7:25pm by bobpursley

calculus
In other words, where is the derivative zero or where is the vertex. f' = 2x + 1 0 = 2 x + 1 x = -1/2 check by completing the square x^2 + x = - 14 x^2 + x + 1/4 = -14 + 1/4 (x+1/2)^2 = - 13 3/4 sure enough, vertex at x = -1/2
Thursday, January 26, 2012 at 8:43pm by Damon

Calculus
No! I am mistaken the square root of 200 is approximately 14 = p 100/14=# of times 7 gives you 98 tables 8 deliveries gives you 112
Saturday, March 3, 2012 at 2:48pm by Susan

Physics
Let T be the rope tension force in each. They are the same in each rope, due to symmetry. 2 T cos45 = 10 N (vertical equilibrium) T = 10N * sqrt2 = 14.14 N
Thursday, May 24, 2012 at 10:20pm by drwls

Math
a. Express f(x)=x^2 - 6x + 14 in the form f(x)=(x-h)^2 + k, where h and k are to be determined. b.Hence, or otherwise, write down the coordinates of the vertex of the parabola equation y=x^2 - 6x + 14.
Sunday, December 9, 2012 at 3:29pm by Bobby

Earth Science
If a sample contains 70g of Carbon 14 and 70g of Nitrogen 14, how many half lives has it undergone? (show all of your work)
Thursday, March 21, 2013 at 7:41pm by Andy

english -
Describe a time when your moral values influenced the way you responded to an issue. What differences did you notice between your logical reasoning process and your moral reasoning process? What were the possible consequences or outcomes of your decision? (150-200) Three years...
Tuesday, March 25, 2008 at 10:05pm by rose

math
it had 11 wins, and 14 losses, right? 11/14
Thursday, December 11, 2008 at 7:59pm by bobpursley

math
2/x = 4/14 Cross multiply: 2 * 14 = 4x 28 = 4x ?? = x
Sunday, May 3, 2009 at 7:35pm by Ms. Sue

MATH Dx
Both 14 and 35 are divisible by 7. 14/35 = 2/5
Monday, August 31, 2009 at 7:40pm by Ms. Sue

math
You question is unclear. The ratio of 14 to 20? 14/20, 7/10, .7?
Tuesday, March 23, 2010 at 11:20pm by PsyDAG

Geometry
V = pi * r^2 * h 549.9 = 3.14 * 5^2 * h 549.9 = 3.14 * 25 * h Solve for h.
Saturday, June 26, 2010 at 9:59am by Ms. Sue

Algebra
Can you tell me if I done this right? (5x10^14)-1 5*10^14-1 2*10-15
Thursday, July 29, 2010 at 9:34pm by michelle

algebra
14 is wrong the answer is 16 because you multiply 6*3 then 5*6 then 6*6 then 6*2 and you get 96 then you do 96/6 and you get 14.
Wednesday, October 6, 2010 at 7:13pm by Aubrey

algebra
-6 - (-4)/ 2 - (-1) = -2 So f(x) = -2/3x + b __ 3 Take a point to find b -6= -2/3(2) + b -6 = -4/3 + b -14/3 = b f(x) = -2/3x - 14/3
Thursday, December 9, 2010 at 5:02pm by ~Proch~

geometry
(0 , 0) , (14 , 11). d^2 = (14 - 0)^2 + (11 - 0)^2, d^2 = 196 + 121 = 317, d = 17.8.
Wednesday, December 15, 2010 at 3:27pm by Henry

math
Surface Area of a Cylinder = 2 pi r 2 + 2 pi r h A = (2 * 3.14 * 5.5^2) + (2 * 3.14 * 5.5 * 4)
Thursday, May 19, 2011 at 10:26pm by Ms. Sue

college??? math
(14/7) / (4/10) (14/7) * (10/4) = 140/28 = 5
Thursday, March 8, 2012 at 7:38pm by Ms. Sue

Algebra
not the way you typed it If you meant 2*7 - 10/(9-4) = 14 - 10/5 = 14 - 2 = 12
Sunday, July 22, 2012 at 11:16pm by Reiny

algebra
5x-7(2-4x) 5x - 14 + 28x 33x - 14
Thursday, August 9, 2012 at 10:45pm by Ms. Sue

maths
assuming you meant 20°C, .7*20 = 14 so it is 14°C in New York.
Saturday, September 22, 2012 at 3:14pm by Steve

calculus
What happened between -4 x log[1 + 3/(14 x)] = and -4 x [3/(14 x) + O(1/x^2)] = How did you get rid of the log? Thx in advance
Saturday, December 1, 2012 at 9:27pm by Help!!

math
Let x = shortest length, then x+14 = longer length. x + x + 14 = 66 Solve for x.
Wednesday, December 5, 2012 at 11:30pm by PsyDAG

math
P = 2L + 2W P = (2 * 22) + (2 * 14) P = ? ~~~~~~~~~~~~~~~~~~~~~~~~~~~ A = LW A = 22 * 14 A = ?
Wednesday, February 13, 2013 at 4:47pm by Ms. Sue

math
13/7= v/8 7v = 104 v = 104/7 v = 14.857 = 14.9
Monday, March 4, 2013 at 3:55pm by Ms. Sue

math
C = pi * d 26 = 3.14 * d 26/3.14 = d 8.28 inches = d
Wednesday, April 3, 2013 at 10:50pm by Ms. Sue

Geometry
As = pi*r^2 + pi*D*h As = 3.14*100 + 3.14*20*42 = 2953 m^2.
Tuesday, June 11, 2013 at 9:44pm by Henry

math
x+2 = -2x + 20 3 x = 18 x = 6 so side = 8 14 - 8 = 8 so 14-x works and 2x + 4 is not 8
Monday, March 10, 2014 at 9:24am by Damon

Chemistry
Take acetic acid and add NaOH to it. That produces sodium acetate, the base of the acid/base system. To make this work, one needs to use acetic acid and add NaOH but not enough to completely neutralize it. For example, if you took 10 moles acetic acid and added 5 moles NaOH, ...
Tuesday, February 14, 2012 at 5:46pm by DrBob222

biochemistry
Enzyme X is a highly pigmented protein that imparts the characteristic color to certain blue-green algae. It also facilitates a reaction necessary to the survival of this species; we can follow the kinetics of this reaction by measuring the conversion of Substance X to ...
Saturday, November 3, 2012 at 9:01am by Ama

Chemistry
First the weighted average for the molar mass of air. (0.8 x molar mass N2) +(0.2 x molar mass O2) = about 28.8 but you can do that more accurately. Next the pressure of the tire in psi. We need that in atmospheres. I went to google and typed in 46.7 psi to atm and it returned...
Monday, March 29, 2010 at 11:27pm by DrBob222

chemistry
Ca(OH)2 ==> Ca^2+ + 2OH^- Ksp = (Ca^2+)(OH^-)^2 Assuming you titrated with HCl, the equation is Ca(OH)2 + 2HCl ==> CaCl2 + 2H2O So at the equivalence point the pH = 7.45. I would convert to pOH (pH + pOH = pKw = 14), then pOH = -log(OH^-) to obtain (OH^-). For Ca^2+, ...
Tuesday, November 1, 2011 at 10:07pm by DrBob222

Math
A series circuit contains a resistor with R = 24 , an inductor with L = 2 H, a capacitor with C = 0.005 F, and a generator producing a voltage of E(t) = 12 sin(10t). The initial charge is Q = 0.001 C and the initial current is 0. Find the charge at time t...
Tuesday, July 10, 2007 at 8:05pm by COFFEE

chem
I would do something like this. (Number of half lives = 6/3 = 2.) 2nn = 26/3 = 22 = 4 and 69 mg/4 = 17.25 Po atoms remain. The mass that emitted must be 69mg-17.25mg = 51.75 mg or 0.05175 grams. I would change that to moles (moles = grams/molar mass) and remember that 1 mole ...
Tuesday, October 5, 2010 at 8:59pm by DrBob222

chemistry
Use PV = nRT, substitute the numbers, and calculate mols CO2 initially, redo the formula and recalculate with new numbers to determine the moles CO2 remaining. The difference equals moles CO2 reacted. Then let X = mass BaO Let Y = mass CaO. ======================== X + Y = 5....
Saturday, November 6, 2010 at 10:50pm by DrBob222

chemistry
I solve these limiting reagent problems the long way by solving two simpler stoichiometry problems. Here is a step by step procedure for solving the simple stoichiometry problems. http://www.jiskha.com/science/chemistry/stoichiometry.html Solve the first time using moles NaI (...
Monday, August 22, 2011 at 6:26pm by DrBob222

Chemistry
a) moles of malachite in 1g: 1g / (221.12g/mol) = .004522 mol (b) moles of CuO produced: .72g / (79.55g/mol) = .009051 mol (c) ratio of moles of CuO produced per moles of malachite decomposed: 2CuO/CuCO3(OH)2 2*79.5/221.1 = 0.719 3. Use the mole ratio of CuO produced per mole ...
Monday, May 3, 2010 at 4:59pm by Sally

Statistics
a.( 13 +14 +17 +14 +17 +15)/6 = 90/6 = 15 b. 15 -+ 1.28 * 1.67/ sqrt(6)) = [ 14.127, 15.873] c. 15 -+ 2.33* 1.67/ sqrt(6)) = [13.411, 16.589]
Tuesday, November 12, 2013 at 2:44pm by Kuai

chemistry
You can still get a pH over 14, those are not the limits. you can also have negative numbers. i can't really explain how or why, i just know that its possible. but i was replying to Joe, because 14 is not the cut off point.
Sunday, April 6, 2008 at 2:05am by Chuck

English Continued
Boy Killed By Carriage A young boy was killed last night when he was run over in the street by a carriage. The driver was told to drive fast and recklessly through the narrow streets by the carriage’s passenger, Marquis Evremonde. The driver revealed to reporters that watching...
Monday, July 7, 2008 at 3:16pm by Emily

Chemistry
Since the answer I got is a bit different from the one given, here is my complete take on this: Assume 1 mole of A and 1 mole of B reacting (This is legitimate since the yield should be independent of the actual number of moles used as long as they are equal). Let's represent ...
Tuesday, July 22, 2008 at 1:16pm by GK

French
Could you check this please thanks. Directions: We are supposed to make a poster on what I would wear at a party, including the color. So I will describe to you what my picture looks like(it's from a magazine) in english, and then I'll type it in french and you can make sure ...
Tuesday, April 28, 2009 at 4:51pm by Paris

Calculus
Recall that the average velocity between times t1and t2 is calculated using vave = y(t2) − y(t1)/t2 − t1. We are given that y = 14t − 1.86t^2. Evaluating at t = 1, we have y(1) = 14(1) − 1.86(1)2 = 12.14. Thus, the average velocity between times 1 and 1...
Saturday, October 8, 2011 at 10:56pm by Prater

chemistry
You can't make aluminum out of hydrogen. In answer to your original question, volumes are proportional to moles, when Pressure and Temperature are constant. You need half as many moles of O2 as you do H2, when H2O is being made in the reaction 2 H2 + O2 = 2 H2O The answer is ...
Sunday, June 8, 2008 at 10:44am by drwls

When everything is in the gaseous state, one may use a short cut; i.e., it isn't necessary to convert to mols of what you have, then to mols of what you want, and back to moles of what you want. Go directly from L of what you have to L of what you want. 25.0L H2 gas x (2 moles...
Tuesday, May 29, 2012 at 6:27pm by DrBob222

Chemistry
Two liquids A and B have vapor pressures of 71.3 and 131 mmHg, respectively, at 25 degrees Celsius. What is the total vapor pressure of the ideal solution made up in the following concentrations? 1.00 mole of A and 1.00 mole of B 2.00 moles of A and 5.00 moles of B
Friday, December 7, 2012 at 3:54pm by Vivian

Calc
Recall that the average velocity between times t1and t2 is calculated using vave = y(t2) − y(t1)/t2 − t1. We are given that y = 14t − 1.86t^2. Evaluating at t = 1, we have y(1) = 14(1) − 1.86(1)2 = 12.14. Thus, the average velocity between times 1 and 1...
Wednesday, September 4, 2013 at 7:14pm by P

science
3 moles of O2 is produced. use avogadros number 6.02e23 molecules in 1 mole. 1mole = 6.02e23 molecules of O2. how many molecules are present in 3 moles of O2??
Thursday, June 13, 2013 at 4:42am by bonjo

chemistry
A 10.0-mL sample of vinegar, which is an aqueous solution of acetic acid, CH3COOH, requires 16.5 XML of a 0.500M NaOH solution to reach the endpoint in a titration (where the moles of acid are equal to the moles of base). What is the molarity of the acetic acid solution
Wednesday, May 4, 2011 at 9:14am by Zarion Gibbs

Physics
A runner weighs 560 N (about 130 lb), and 74% of this weight is water. (a) How many moles of water are in the runner's body? moles (b) How many water molecules (H2O) are there? molecules I was able to get part (a), but I'm not sure how to get part (b)
Monday, April 28, 2008 at 11:53am by Tasha

General Chemistry
moles glucose = 1.5/molar mass glucose = ??. Then 1 mole glucose contains 6.022 x 10^23 molecules. Therefore, ?? moles will contain xx molecules glucose. Then each molecules contains 6 C, 6 O, and 12 H atoms.
Monday, May 17, 2010 at 10:20am by DrBob222

chemistry
1 L of 0.02 M = M x L = 0.02 moles moles KIO3 = grams/molar mass 0.02 x 214.001 = ?? grams KIO3. Ideally this is what you want. You can work out the details (I would do the percent by using +1% and -1% of 0.02 grams and recalculate).
Monday, October 11, 2010 at 2:37pm by DrBob222

chemistry
Use the formula moles = mass/Mr Mr of sodium = 23 Rearrange the equation to make mass the subject. mass = moles x Mr and put in the numbers... mass = 2 x 23 = 46g Hope this helps
Tuesday, February 8, 2011 at 8:52am by Gemma

Chemistry
First You convert 645.0 torr to atm, and also mL to L. You use PV=nRT, to find the number of moles. Then you use the number of moles to get the molar mass. mol= mass/molar mass
Wednesday, March 30, 2011 at 6:02pm by wini

Chemistry
A sample of 0.30 moles of a metal M reacts completely with excess fluorine to form 18.69 grams of MF2. How many moles of F are in the sample of MF2 that forms? M + F2 ---> MF2 How many grams of M are in this sample of MF2 ?
Friday, July 29, 2011 at 4:00pm by Brooke

Chemistry
100-31.0=69.0g, or better yet, 0.069 kg of solvent. 31g of C2H6O2*(1 mole/62.06810 g)= moles of C2H6O2 m=molality=moles of C2H6O2/0.069 kg of solvent
Thursday, March 14, 2013 at 3:57pm by Devron

Chemistry
Partial pressure=(moles of Ar/total moles of gas mixture)*total pressure Partial pressure of Ar=(0.48mol/1.42mol)*1.68 atm ****Answer contains three significant figures.
Tuesday, March 4, 2014 at 1:39am by Devron

college
convert grams of Mg to moles of Mg, then use the molar ratio to determine the moles of Mg and finally convert it into grams of Mg.
Sunday, February 28, 2010 at 5:53pm by isha

Chemistry
balance it. then look at the mole ratio of methane to CO2. How many moles of methane do you start with? Using the mole ratio, how many moles of CO2 do you get? How many grams is that?
Tuesday, September 21, 2010 at 1:26pm by bobpursley

physics
find the moles of helium from PV=nRT Now,knowing the moles, find the volume at the altitude. PV=nRT, solving for volume
Sunday, April 22, 2012 at 5:40am by bobpursley

chemistry need help
1. Divide the grams of aluminum by the molar mass of aluminum (26.98g/mole) to convert mass to moles. 2. Multiply the number of moles of aluminum by Avogadro's Number (6.02x10^23 atoms/mole).
Wednesday, March 25, 2009 at 9:59pm by GK

Chemistry
write and balance the equation. then figure the moles of potassium carbonate. Look at the mole ratio of KCl to potassium carbonate. Multipy the originalmoles of postassium carbonate by that ratio, and you have the moles of KCl. Convert that to grams.
Sunday, October 17, 2010 at 11:11am by bobpursley

Chemistry
how many moles of O2 is 25.1 liters (STP):answer: 25.1/22.4 2H2O>>2H2 + O2 so according to the balanced equation, you need 2*25.1/22.1 moles of water, convert that to grams.
Friday, July 22, 2011 at 4:06pm by bobpursley

chemisty
If your name is really Stacy, that's a pretty name, and I wouldn't think of calling you Shirley. We welcome you back any time but we want to know how you would approach the problems and/or what you know and what you don't understand. 1. mass percent = mass solute/100 g ...
Tuesday, December 14, 2010 at 4:41pm by DrBob222

Chemistry
Gasoline can be represented by octane C8H18. Its combustion, in the most straight-forward sense is to carbon dioxide and water. 2C8H18 + 25O2 ~> 16CO2 + 18H2O so, he needs 6.45km / .0147km/g = 438.7755g of gas. That assumes complete combustion, of course. mole weight is ...
Monday, January 16, 2012 at 11:24am by Steve

Pages: <<Prev | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | Next>>

Search
Members