Monday

May 25, 2015

May 25, 2015

Number of results: 27,787

**chemistry**

pure zinc metal into a solution of copper(II) sulfate, the zinc will slowly dissolve to produce zinc sulfate solution, and the copper(II) ion of the copper(II) sulfate will be converted to metallic copper. Write the unbalanced equation for this process. (Include states-of-...
*October 2, 2010 by astoeck*

**chemistry- Thank you**

Suppose you add 81 ml of dilute acid to 54 ml of water. Both the water and acid were at room temperature (22 C) before being mixed. The temperature of the solution increased to 42 C. How much energy (in kJ) was released by the dissolution of the acid if the specific heat ...
*October 17, 2010 by Jazmin*

**Hayden**

Chloroacetic acid has a relatively large equilibrium constant, so at low acid concentrations it is necessary to use the quadratic equation in order to calculate the concentrations of the aqueous species. Ka for ClCH2COOH is 1.4 ´ 10-3. For the problems that follow, consider ...
*June 19, 2010 by leona*

**Chemistry**

Lead(II) nitrate solution reacts with potassium iodide solution to produce lead(II) iodide and potassium nitrate. The answer in the book is: Pb(NO3)2(aq) + 2 KI(aq) ---> 2KNO3(aq) + PbI2(s) I understand how to write and balance the equation. However, I am confused about how...
*January 28, 2011 by Jeff*

**Chemistry**

A chemistry student weighs out 0.123 grams of chloroacetic acid into a 250. milliliter volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.2100 moles/liter NaOH solution. Calculate the volume of NaOH solution the student will need...
*January 19, 2012 by Deborah*

**chemistry**

Please check this for me..thank You have a 4.0 L steel tank containing hydrogen gas. You are able to heat or cool the tank and meaurse the pressure of the gas. 1.If you immersed in this solution a semi-permeable sack containing another solution of potassium nitrate prepared by...
*April 23, 2012 by cateye*

**Honors Chemistry**

If the percent (mass/mass) for a solute is 20% and the mass of the solution is 300 g, what is the mass of the solute in solution?
*May 25, 2010 by Emily*

**Algebra 2**

Solve each equation. 1. (|3x -4|)/(-5) = 6 A: no solution 2. (|2x -5|) = x + 3 A: x = 8 or x = 2/3 Solve each inequality. 3. |5x + 15| > 20 A: x > 1 and x < -7 4. [(|x - 2|)/ (4) greater than or equal to 5 A: -18 < x < 22 5. (-3) x (|5x - 8|)- 5 greater than or...
*October 13, 2014 by Victoria*

**Chemistry. Please help!**

A 20.29 g sample of impure MgCO3 is completely decomposed at 1000oC in previously evacuated 2.0 L reaction vessel. After the reaction was complete the solid residue had a mass of 15.9 g. Assume that only MgCO3 could produce gas CO2 what percent of original sample was magnesium...
*December 3, 2008 by Jordan*

**statistics**

Estimation is best defined as: 1. a process of inferring the values of unknown population parameters from those of known sample statistics 2. a process of inferring the values of unknown samples statistics from those of known population parameters 3. any procedure that views ...
*November 24, 2010 by joe*

**Statistics**

According to the U.S. Federal Highway Administration, the mean distance traveled per shopping trip by Americans was 10.0 miles in 1983. A random sample of 25 shopping trips for this year gave a mean distance traveled of 12.0 miles with a population sample standard deviation (s...
*April 26, 2011 by Anonymous*

**CHEMISTRY plz help**

In the accompanying chart are appropriate vapor pressures for benzene and toluene at various temperatures: Temp (C) mmHg Temp (C) mmHg Benzene 30 120 Toluene 30 37 40 180 40 60 50 270 50 95 60 390 60 140 70 550 70 200 80 760 80 290 90 1010 90 405 100 1340 100 560 110 760 d. ...
*October 17, 2013 by Aishwarya*

**Chemistry**

Help with lab report Need Help finishing my lab report.KNOWN VALUES ARE V OF HCL=50ML,M=2.188.V OF NAOH=55.3ML,M=2.088.INTIAL TEMP FOR HCL=22.5C,NAOH IS 23C.this is for part A: Mass of final NACL solution assuming that the density of a 1 M Nacl solution is 1.04 g/ml? Heat ...
*October 26, 2012 by randy*

**Chemistry**

You are going to be provided with 1 0.50 g sample of magnesium oxide. Treatment of this sample with hydrochloric acid (HCl) will take all of the MAGNESIUM in the oxide and change it into magnesium chloride, MgCl2 You will add 100 ml of 1.0 M HCl to the 0.50 g of magnesium ...
*October 1, 2008 by JC*

**Grammar**

Which word(s) does the clause in CAPS modify? 1.Will you wait UNTIL MR.HAMILTON RETURNS? A.you B.Will wait C.wait D.here B? 2.Our music teacher, Mrs.Goode, offered a solution that SURPRISED US ALL. A.teacher B.Mrs.Goode C.solution D.offered C Are these correct? Thanks -MC
*May 13, 2009 by mysterychicken*

**High school AP chem**

The solubility of Mn(OH)2 is 3.04 x 10^-4 gram per 100 ml of solution . A) write the balanced chem equation for Mn(OH)2 in aqueous solution B) calculate the molar solubility of Mn(OH)2 at 25 degrees celcius C) calculate the value of the solubility product constant, Ksp, for Mn...
*April 1, 2014 by Chem review question *

**Chemistry**

calculate oh- and ph in a solution in which dihydrogen phosphate ion is 0.335 M and hydrogen phosphate is 0.335 M. This is a homework question, where I have the solution, which is 0.335/0.335, which I get, but then I am supposed to multiply this (1)by a number 6.2x10-8? I have...
*April 9, 2015 by Jessica*

**Chemistry**

How would the titration curve of hydrochloric acid solution differ if barium hydroxide was used to titrate instead of sodium hydroxide? How would the titration curve of hydrochloric acid solution with sodium hydroxide differ from the titration curve of acetic acid solution ...
*March 6, 2012 by Niki*

**Chemistry**

Ho w
much
water
would
you
need
to
add
to
500
mL
of
a
0.3
M
calcium
nitrate
solution
to
make the
solution
0.1
M? A.
...
*October 17, 2014 by Luis*

**math, help**

What are two solutions for 3x-y=0 am i correct on this inorder to graph (0,0) and (2,6) Because the line goes through (0,0) so how do i get two solutions from that line? You can get two solutions from that line because the first solution (0,0) is from the start of the axons x,...
*February 10, 2007 by jasmine20*

**Algebra**

please check my answers. thanxs! Solve the polynomial inequality and graph the solution set on a number line. Express the solution set in interval notation. x^2 - 6x + 5 > 0 -I got (-ininity,1) u (5, infinity) x^2 - 3x - 18 < 0 -I got (-infinity,-3) u (6, infinity) x^2...
*October 24, 2007 by Liz*

**chemistry**

Explain why a buffer made of equal concentrations of HF and F- does not change in pH when a small amount of HCl (a strong acid) is added to the solution. Does the HCl dissociate into ions when it is added to the solution? What do the hydrogen ions react with? Why don’t these ...
*April 23, 2012 by Anonymous*

**chemistry**

Explain why a buffer made of equal concentrations of HF and F- does not change in pH when a small amount of HCl (a strong acid) is added to the solution. Does the HCl dissociate into ions when it is added to the solution? What do the hydrogen ions react with? Why don’t these ...
*May 4, 2012 by Anonymous*

**radical equation - no solution right?**

radical sign (w + 5) = 2 In all my problems there are a letter variable on the end example: radical sign (-u + 30) = u I then square both sides, drop the radical sign then (u+6)(u-5)=0 then check to see if they are both true I guess my question is this is a no solution problem...
*October 11, 2007 by Nik H.*

**Chemistry**

What effect on the molar mass of the unknown acid would each of the following have-that is-would it make the calculated molar mass high, low, or would it have no effect? 1. Adding 5 drops of phenolphthalein instead of 1 drop. 2. Using a standard NaOH solution that has been ...
*April 3, 2013 by Sean*

**Chemistry**

I am very confused on this problem. Any help would be great: 50 g of silver nitrate is mixed with 50 g of hydrochloric acid in a water-based solution. A white precipitate forms (silver chloride.) The solution is filtered and the white precipitate collected and dried. The dried...
*June 23, 2009 by Ted*

**Statistics**

Can someone please help with this problem to advise how to set up and in the book Essential of Statistics for the Behavioral Sciences. A researcher is investigating the effectiveness of a new study-skills training program for elementary school children. A sample of n=25 third-...
*December 20, 2013 by Lyn*

**math**

Consider an equilateral triangle with points located at each vertex and at each midpoint of a side. (See picture.) This problem uses the set of numbers {1, 2, 3, 4, 5, 6}. Place one number at each point. Call the sum of the three numbers along any one side (two vertices and ...
*October 10, 2014 by al*

**Statistics (46)**

The 2003 Statistical Abstract of the United States reported the percentage of people 18 years of age and older who smoke. Suppose that a study designed to collect new data on smokers and nonsmokers uses a preliminary estimate of the proportion who smoke of .30. a. How large a ...
*May 6, 2014 by Mia*

**Economics (45)**

The 2003 Statistical Abstract of the United States reported the percentage of people 18 years of age and older who smoke. Suppose that a study designed to collect new data on smokers and nonsmokers uses a preliminary estimate of the proportion who smoke of .30. a. How large a ...
*May 9, 2014 by Mia*

**statistics**

The 2003 Statistical Abstract of the United States reported the percentage of people 18 years of age and older who smoke. Suppose that a study designed to collect new data on smokers and nonsmokers uses a preliminary estimate of the proportion who smoke of .32. a. How large a ...
*January 18, 2015 by Anonymous*

**chemistry**

The phosphorus in a completely dried fertilizer sample weighing 0.4498 grams was precipitated as MgNH4PO4*6H2O. The precipitate weight was determined to be 236.8 mg and ignited to Mg2P2O7. The weight of the ignited precipitate was 268.9 mg. Calculate the percent phosphorus. My...
*August 31, 2007 by smiley*

**Chemistry**

A 35.00 mL sample of water at 30.0°C is placed in an open container with an external pressure of 1.00 atm. 30.0 kJ of heat is added to the water sample. The density of water is 1 g/mL. (a) How many grams of liquid water remain at the end of the process? Like, the equation I ...
*February 11, 2015 by N*

**Solutions**

When adding 100mL of water to a solution of 50grams of KI in 400mL of water, the total amount of KI in the new solution will be how many grams? Did I miss something here? The total amount of KI, if no extra is added and none taken away, MUST be 50 grams? That is what I thought...
*February 25, 2007 by Kellie*

**chemistry**

The enzyme Y catalyzes the elementary reaction AB-->A + B An enzyme concentration of 1.0M Y can convert a maximum of 0.5M AB to the products A and B per second. What will happen when each of the following is added to a solution that contains 1.0M Y and 0.8M AB? I have to ...
*March 22, 2009 by tomi*

**chemistry**

the vapor pressure of carbon sulfide is 355.6 torr at 25 degrees Celsius. what is the vapor pressure of a solution prepared by dissolving 12.52 g naphthalene (C10H8, 128.2 g/mol) in 125.0 mL CS2 liquid (76.14 g/mol, 1.261 g/mL)? Assume the solution obeys Raoult's law, and ...
*March 4, 2015 by alexis*

**Business**

Envision that you run a highly successful tattoo and piercing parlor in a small West Coast city. You are fairly certain that between you and your key competitor, you have saturated your target audience of people in their teens and 20s. To grow your business, you need to reach ...
*September 5, 2012 by Tracey*

**algebra 1 help**

1)|J|/5+1=-4 a. no solution b. j=15 or -15 c. j=-25 d.j= -15 my answer is A 2) 1/6|4x-8|=6x a. x=-7, x=11 b. x=8/3, x=8/5 c. no solution d. x=-1/4, x=1/5 my answer is J
*April 25, 2013 by hips*

**chemistry 12**

Calculate [H3O^-] in a 0.15M solution of benzoic acid, HC7H5O2(aq) having a Ka of 6.4 x 10^-5 I got. 6.4x10^-5=(x)(x)/0.15 6.4x10^-5= x^2/0.15 6.4x10^-5 x 0.15 = x^2 square root of 9.6x10^-6 = square root of x^2 x= 0.003098 The pH solution is -log [0.003098] = 2.50 b.) ...
*October 13, 2011 by shelly*

**Chemistry**

Consider the titration of 20.0mL of 0.300M acetic acid, HAc, with 0.150M NaOH solution. Ka=1.75*10^-5 HAc + NaOH ---> NaAc + H2O What is the composition of the solution at the equivalence point of the titration? Give both the formula of the compound and its concentration. ...
*May 1, 2015 by Jonah*

**math**

a chemist has a solution that is 20 percent alcohol by volume. which of the following expressions represents the percent of alcohol by volume when m litersof the solution is mixed with h liters of pure alcohol and p liters of water? a) 20(m+h+p)% b) 20(m+h)/m+h+p) c)20?h+p d) ...
*July 23, 2009 by Jason P*

**chmistry**

a solutiona solution is made by dissolving 3.75g of a pure nonvolatile solute in 95g of acetone. the boiling point of pure acetone was observed to be 55.95 Centigrade that,and that of the solution was 56.50 Centigrade.if the molar boiling point elevation constant(Kb)of acetone...
*November 20, 2012 by bb*

**Chem**

The solubility of Mn(OH)2 is 3.04 x 10^-4 gram per 100 ml of solution . A) write the balanced chem equation for Mn(OH)2 in aqueous solution B) calculate the molar solubility of Mn(OH)2 at 25 degrees celcius C) calculate the value of the solubility product constant, Ksp, for Mn...
*April 1, 2014 by Bee*

**chemistry**

A solution contains naphthalene (C10H8) dissolved in hexane (C6H14) at a concentration of 11.39{\rm \\%} naphthalene by mass. Calculate the vapor pressure at 25 ∘C of hexane above the solution. The vapor pressure of pure hexane at 25 ∘C is 151 torr.
*February 8, 2015 by kales*

**statistics/ Ho and Ha?**

* I just wanted to know if I'm setting up the Ho and Ha correctly. An herbal supplement is advertised as producing an increase in strength and stamina. Sample of n=36 adults is obtained and each person is told to take the regulary daily dose of the herb for 30 days. At the end...
*March 11, 2008 by Tina*

**Biochemistry**

Determine the MAX amount of titrant you will possibly need for your titration. Your unknown solution has been prepared by dissolving btw 0.05-0.09mol of zwitterion form of the amino acid in 1L of ~ 0.1M HCl solution. you will titrate 50mL of that amino acid with 0.5M NaOH. ...
*May 18, 2015 by Abba*

**Biochemistry**

Determine the MAX amount of titrant you will possibly need for your titration. Your unknown solution has been prepared by dissolving btw 0.05-0.09mol of zwitterion form of the amino acid in 1L of ~ 0.1M HCl solution. you will titrate 50mL of that amino acid with 0.5M NaOH. ...
*May 18, 2015 by Abba*

**Biochemistry**

Determine the MAX amount of titrant you will possibly need for your titration. Your unknown solution has been prepared by dissolving btw 0.05-0.09mol of zwitterion form of the amino acid in 1L of ~ 0.1M HCl solution. you will titrate 50mL of that amino acid with 0.5M NaOH. ...
*May 19, 2015 by Abba*

**chemistry**

A solution containing 5.00g of solid Al2(CO3)3 dissolved in water to a total volume of 200. mL is combined with 140. mL of 1.0 M HBr. Write the total of ionic equation for the reaction described below and find the molar concentration of all ions remaining in a solution that is...
*April 16, 2012 by SELDIL*

**Chemistry**

I want to see if i got my answer correct for #1 but I need help on #2 1.A 150g aluminum pan containing 500g of water is heated on a stove for 5 minutes. The temperature goes from 23.5C to 48.9C. How much heat was absorbed. (s for Al is .900j/g C, s for H2O is 4.184 j/g C) I ...
*March 8, 2011 by Ashley*

**Chem**

I want to see if i got my answer correct for #1 but I need help on #2 1.A 150g aluminum pan containing 500g of water is heated on a stove for 5 minutes. The temperature goes from 23.5C to 48.9C. How much heat was absorbed. (s for Al is .900j/g C, s for H2O is 4.184 j/g C) I ...
*March 8, 2011 by Ashley*

**Bio**

One way to determine the concentration of protein in a solution is to perform a "protein assay". There are several assay kits on the market that one can use, but they all rely on the common paradigm that the aromatic amino acid residues of a protein combine with the reagents ...
*June 17, 2006 by Josh*

**Chemistry**

How do I do this problem? 1. A student did an alkalinity determination correctly, except that the sample titrated had a volume of 90.0 mL. Volume A was found to be 4.50 mL and Volume B was 7.00 mL. a) Calculate the alkalinity value from these data and then calculate the ...
*March 13, 2007 by Joe*

**statistics**

A nutritionist studying weight gain for college freshmen obtains a sample of n = 20 first year student at the state college. Each student is weighed on the first day of school an again on the last day of the semester. The following scores measure the change in weight, in ...
*June 9, 2013 by Tami*

**Algebra**

Could you please check my answers and help with the ones I can't figure out- 1. Solution to the radical function sqrt(12x+1) = 1 is x = 0 True or False I think it is true according to my calculations 2.Solve x = sqrt(8x) 8x = x^2 x^2 - 8x = 0 x(x-8) = 0 x = 0 x-8 =0 x=8 the ...
*October 19, 2010 by JayLynne-Please check*

**chemistry**

Help with Beer's Law lab experiment question! So we were told to calculate the concentration of 5 standard solutions but I don't know how to do that exactly. The Concentration of the solution in flask B was .0024 M and our lambda max (max absorption) was at 515 nm. I know the ...
*September 6, 2010 by Anonymous*

**Chemistry**

chemistry student weighs out 0.123 grams of chloroacetic acid (HCH2ClCO2) into a 250. milliliter volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.1200 moles/liter NaOH solution. Calculate the volume of NaOH solution the student...
*January 19, 2012 by Deborah*

**Chemistry**

A chemistry student weighs out 0.123 grams of chloroacetic acid (HCH2ClCO2) into a 250. milliliter volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.1200 moles/liter NaOH solution. Calculate the volume of NaOH solution the ...
*January 19, 2012 by Deborah*

**Chemistry**

A chemistry student weighs out 0.123 grams of chloroacetic acid (HCH2ClCO2) into a 250. milliliter volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.1200 moles/liter NaOH solution. Calculate the volume of NaOH solution the ...
*January 19, 2012 by Deborah*

**Chemistry**

In a constant-pressure calorimeter, 50.0 mL of 0.300 M Ba(OH)2 was added to 50.0 mL of 0.600 M HCl. The reaction caused the temperature of the solution to rise from 24.50 degrees C to 28.59 degrees C. If the solution has the same density and specific heat as water, what is ...
*February 9, 2012 by Eric*

**Chemistry**

In a constant-pressure calorimeter, 50.0 mL of 0.300 M Ba(OH)2 was added to 50.0 mL of 0.600 M HCl. The reaction caused the temperature of the solution to rise from 24.50 degrees C to 28.59 degrees C. If the solution has the same density and specific heat as water, what is ...
*February 10, 2012 by Eric*

**Algebra 2**

1.) According to the American College Test (ACT), results from the 2004 ACT testing found that students had a mean reading score of 21.3 and a standard deviation of 6.0. The scores are normally distributed. A student scores a 35. What percent of the data would contain that ...
*April 4, 2014 by Lanie*

**chemistry**

A solution contains naphthalene(C10H8) dissolved in hexane (C6H14) at a concentration of 14.52 % naphthalene by mass.Calculate the vapor pressure at 25 degrees C of hexane above the solution. The vapor pressure of pure hexane at 25 degrees C is 151 .
*August 5, 2010 by jay*

**Chemistry**

An acid HA has Ka = 2.28 x 10^-4. The % ionisation of this acid in a 0.170 M solution of the acid in water is? An acid HA has Ka = 2.28 x 10^-4. The % ionisation of this acid in a 0.170 M solution of the acid in water is closest to a. 2.930 % b. 3.662 % c. 2.564 % d. 0.498 % e...
*May 26, 2011 by Cheryl*

**Chemistry**

Calculate the solid needed to make a 250ml solution that is 0.34M in sodium cation, using sodium sulfate decahydrate. I came up with 13.685g. but how do I make that into 250ml of a solution that is0.34M in sodium cation?
*October 27, 2011 by Denise*

**chemistry**

Using the equipment below, explain how to prepare a 0.00052M HCl solution from a reagent bottle containing 0.13M HCl using only the equipment listed below. Note, you may make multiple dilutions, but you are not allowed to combine volumes. For example, if you need 2 mLs of a ...
*July 2, 2013 by Jill*

**chemistry**

what evidence supports the clarification that H2Se 03 is an acid and how do i identify the positive ions present inthe aqueous solution I am a little confused by the word "clarification" in your question. What evidence do you have? Could you measure the pH of the solution? ...
*January 30, 2007 by mickey*

**college**

0.02 g of CaCO3 is dissolved in 1 L of water. Calculate the moles of calcium carbonate that have dissolved in the water, the moles of Ca2+ ions in solution, and the number of Ca2+ ions in solution?
*January 27, 2010 by mike*

**Chemistry**

0.02 g of CaCO3 is dissolved in 1 L of water. Calculate the moles of calcium carbonate that have dissolved in the water, the moles of Ca2+ ions in solution, and the number of Ca2+ ions in solution?
*January 27, 2010 by mike*

**MAT222**

-x+2y=-2 x-2y=2 the system has no solution the system has a unique solution: the system has infinitely many solutions. they must satisfy the following equation: y= the answer is the system has infinitely many solutions. i just don't understand how to get the equation y=?
*September 1, 2014 by Kia*

**College Chemistry**

I DO NOT understand the following! Please HELP :) 1st Part Substances A, B, and C can all act as oxidizing agents. In solution, A is green, B is yellow, and C is red. In the reactions in which they participate, they are reduced to A-, B-, and C- ions, all of which are ...
*November 10, 2010 by Lisa*

**college stats **

help please!!! 1. The average number of bumped passengers per day on FliRite Airlines is 2.47 with a standard deviation of 1.75. For a random sample of 40 days, what is the chance the average number of bumped passengers in the sample is between 2 and 2.75? a. About 91% b. ...
*July 12, 2013 by penelope*

**Chemistry**

A solution contains 0.0653g of compound in 8.31g of ethanol. The molarity of the solution is 0.0368m. Calculate the molecular weight of the compound For Further Reading Chemisty - drbob222, Thursday, February 7, 2008 at 9:40pm The molarity of the solution can't be 0.0368 m. It...
*February 9, 2008 by Lauren*

**chemistry**

I need assistance with this question please. "The equation of the line for a graph of voltage (Ecell) versus log[Cu2+] was y= -0.0166x - 0.0082. The voltage of a solution with an unknown [Cu2+] was measured against the same reference cell, under the same conditions; the ...
*March 15, 2011 by upthecreek*

**Kinematics**

A 55.0kg box rests on a horizontal surface. The coefficient of static friction between the box and the surface is .300. What horizontal force must be applied to the box for it to start sliding along the surface? Please write out the solution. I am getting an answer of 165N but...
*October 5, 2012 by Jaybird*

**chemistry**

Suppose you add 92 ml of dilute acid to 46 ml of water. Both the water and acid were at room temperature (22 C) before being mixed. The temperature of the solution increased to 39 C. How much energy (in kJ) was released by the dissolution of the acid if the specific heat ...
*January 31, 2015 by danny*

**AP Chemistry**

1. Equilibrium 2SO3(g) <--> O2(g) + 2SO2(g) A 3.21g sample of sulfur trioxide is placed in a 2.25 L cylinder and allowed to reach equilibrium at a constant temperature of 500 , as shown in the above equation. Analysis shows 1.23 X 10^-2 mol of sulfur dioxide at ...
*April 10, 2007 by anonymous*

**statistics**

Suppose that large dogs weights are normally distributed with a mean of 100 pounds and a standard deviation of 10 pounds. If one of these dogs is picked random: a) what is the probability that the dog will weigh over 110 pounds? b) what is the probability that the dog will ...
*March 26, 2010 by Anonymous*

**Math-Stat Help **

In a random sample of 78 teenagers, 32 admit to texting while driving. Construct a 98% confidence interval for the percentage of teenager that text while driving. Start by showing that conditions for constructing a confidence interval are met. 1) Check conditions 2) confidence...
*April 11, 2013 by MELISSA *

**chemistry**

An ideal liquid solution has two volatile components. In the vapor in equilibrium with the solution, the mole fractions of the components are (a) both 0.50; (b) equal, but not necessarily 0.50; (c) not very likely to be equal; (d) 1.00 for the solvent and 0.00 for the solute. ...
*February 20, 2010 by david*

**College Chemistry**

A student weighs out 0.568 g of KHP (molar mass=204g/mol) and titrates to the equivalence point with (36.78 cm cubed which is 3) of a stock NaOH solution. What is concentration of stock NaOH solution? KHP is an acid with one acidic proton. The word cubed is in word form ...
*October 22, 2010 by Elleni*

**Chemistry**

A certain headache relief tablet is composed of monoprotic acetylsalicylic acid(C9H8O4(s)) and an inert filler. A 4.00 g tablet was crushed and dissolved to make 40.0 mL of solution. The solution was then titrated with 0.900 mol/L NaOH(aq). The volume of NaOH(aq) needed to ...
*June 9, 2011 by Maya*

**Chemistry**

Predict the standard cell potential and calculate the standard reaction Gibbs free energy for galvanic cells having the following cell reactions: 2H2+O2=2H2O in acidic solution 2H2+O2=2H2O in basic solution I understand the idea behind the problem, but I am not sure how the ...
*March 10, 2014 by Anonymous*

**Statistics and Probability**

One six-sided fair die is rolled, and one two-sided fair coin is tossed. If the coin turns up heads, then the number of spots showing on the die is the value (score) for that trial. If the coin is tails then twice the number of spots showing on the die is the value (score) for...
*December 16, 2010 by Laura*

**statistics**

Suppose only 75% of all drivers in a certain state regularly wear aseat belt. A random sample of 500 drivers is selected. What is theprobability that a). Between 360 and 400 (inclusive) of the drivers in the sampleregularly wear a seat belt? b). Fewer than 400 of those in the ...
*October 21, 2010 by Dre*

**chem**

how to find mass of aspirin if I used 0.2845g of the powder(crushed apririn) with 1mL of 6.0 mol/L of Nacl? Does the dilution(the above chemicals are diluted in a 500mL volumetric flask) matter ,and does adding the HCL/Fe^3+ stock solution in the end matter (1.00 mL of the the...
*April 23, 2015 by linda*

**chemistry**

A radioactive sample contains 3.25 1018 atoms of a nuclide that decays at a rate of 3.4 1013 disintegrations per 26 min. (a) What percentage of the nuclide will have decayed after 159 d? % (b) How many atoms of the nuclide will remain in the sample? atoms (c) What is the half-...
*April 16, 2010 by Trixie *

**Metals**

Transition metals (also called heavy metals) form insoluble compounds with hydroxide ions. Therefore, it is possible to extract heavy metal ions from water by raising the pH. The precipitation reaction between cadmium(II) and hydroxide is shown below. Cd2+(aq) + 2OH−(aq...
*April 19, 2015 by Chemistry*

**statistics**

You are a travel agent and wish to estimate, with 98% confidence, the proportion of vacationers who use an online service or the Internet to make travel reservations. Your estimate must be accurate within 4% of the population proportion. a) No preliminary estimate is available...
*April 6, 2011 by alex*

**Chem**

The space occupied by any sample of matter is called its __________. volume
*January 14, 2007 by Dennis*

**chemistry**

if a sample of cough syrup has the mass of 50.0g and a density of 0.950 what is the volume
*September 18, 2007 by Amy*

**LI**

Can some please show me sample essays from previous test and how they analyzed it.
*January 30, 2008 by lou*

**Chem**

How many moles of copper sulfate, CuSO4 are in a o.671 g sample? How do I start on this?
*March 3, 2008 by Mark*

**English**

funny survey sample please! with scoring and interpretation pls!
*June 19, 2008 by Grace*

**math**

List all possible events in the sample space with outcomes A, B, and C.
*August 26, 2008 by Jope*

**infants**

i need sample pamplet on great tips for parnets to read.
*October 13, 2008 by miesha*

**statistics**

How does the sample size differ between qualitative and quantitative methods? Why?
*October 20, 2008 by nicky*

**statistics**

2. How does the sample size differ between qualitative and quantitative methods? Why?
*October 22, 2008 by nicky*

**statistics**

If a sample of size 30 is selected, the value of A for the probability P(t greater or less A) = 0.01 is?
*August 1, 2009 by Lina*

**Algbera 1**

Need an sample of two step equation word problem.
*October 11, 2009 by alyssa*