Sunday

May 29, 2016
Number of results: 30,380

**Chem 151**

A solution of ammonia and water contains 3.50×10^25 water molecules and 5.00×10^24 ammonia molecules. How many total hydrogen atoms are in this solution?
*September 13, 2011 by Tyler*

**chemistry**

A chemist wants to make 5.50 L of a 0.300 M lithium phosphate solution. What mass of lithium phosphate must be used to make this solution?
*November 3, 2014 by James*

**Chemistry**

What is the molarity of a solution that contains 2.17 moles of (SrCl2) in 2,660ml of solution? I know that the formula is molarity=moles/liters Liters=.2660
*June 21, 2015 by Ocean*

**AP CHEM**

I have multiple... 1) If a metal ore contains 23.1% pure metal, how many pounds of pure metal can be obtained from 38 pounds of metal ore? Answer in units of pounds. 2) For the reaction 3 F2 + Cl2 → 2 ClF3 , what is the maximum amount of ClF3 (92.4482 g/mol) which could ...
*October 13, 2015 by Shannon*

**statistics**

Customers arrive at a movie theater at the advertised movie time only to find that they have to sit through several previews and prepreview ads before the movie starts. Many complain that the time devoted to previews is too long (The Wall Street Journal, October 12, 2012). A ...
*November 16, 2014 by sean*

**Chemistry**

Redox Titrations I did a redox titration of NaBO3 with KMnO4. I used a .0545 M NaBO3 solution, and an average of .026 L of .01M KMnO4. I have to standardize the KMnO4 solution, does anyone know how to do this?
*March 25, 2009 by Ryan*

**Chemistry**

Trichloroacetic acid (CCl3CO2H) is a corrosive acid that is used to precipitate proteins. The pH of a 0.050 M solution of trichloroacetic acid is the same as the pH of a 0.040 M HClO4 solution. Calculate Ka for trichloroacetic acid.
*November 23, 2011 by Kaleen*

**mixture**

Sugar solution is composed of 40 grams of sugar and 200 grams of water. How many grams of sugar must be added to make a 60% sugar solution? (Kindly write the equation..... tnx)
*November 22, 2012 by HELP HELP MNHS*

**chemistry**

You have a solution that contains 340ml of water and 20ml of ethanol. Find the concentration of ethanol in this solution in each of the following units: (density of water is 1.00 g/ml, density of ethanol is 0.789g/ml)
*February 18, 2014 by Anonymous*

**chemisty problem help**

Carbon-12 contains 6 protons and 6 neutrons. The radius of the nucleus is approximately 70 pm. Calculate the volume of the nucleus and the volume of the atom. What percentage of the carbon atom's volume is occupied by the nucleus? Can someone tell me how to do this? Volume= 4/...
*February 8, 2007 by Tagen*

**Statistics**

28. A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spend studying per week. Based on a simple random sample, they surveyed 144 students. The statistics showed that students studied an average of...
*October 22, 2011 by Steph*

**chemistry**

Suppose 70.00 mL of a lithium hydroxide, LiOH, solution requires 55.42 mL of a 0.1050 M solution of propanoic acid, C2H5COOH, for neutralization. LiOH + C2H5COOH ® C2H5COOLi + H2O What is the concentration of the base solution? 0.08313 M 0.1663 M 0.3325 M 0.6650 M Question 2 4...
*October 9, 2010 by hope*

**statistics**

The average gasoline price of one of the major oil companies has been $3.20 per gallon. Because of cost reduction measures, it is believed that there has been a significant reduction in the average price. In order to test this belief, we randomly selected a sample of 36 of the...
*November 12, 2013 by Alex*

**chemistry**

Two aqueous solutions of sucrose, C12H22O12, are mixed. One solution is 0.1495 M sucrose and has d = 1.018 g/mL; the other is 12.00 sucrose by mass and has d = 1.038 g/ml. Calculate the moles C12H22O12 percent in the mixed solution. Please provide steps
*February 17, 2010 by anonymous*

**chemistry**

Two aqueous solutions of sucrose, C12H22O12, are mixed. One solution is 0.1495 M sucrose and has d = 1.018 g/mL; the other is 12.00 sucrose by mass and has d = 1.038 g/ml. Calculate the moles C12H22O12 percent in the mixed solution. Please provide steps
*February 17, 2010 by anonymous*

**chemistry**

Two aqueous solutions of sucrose, C12H22O12, are mixed. One solution is 0.1495 M sucrose and has d = 1.018 g/mL; the other is 12.00 sucrose by mass and has d = 1.038 g/ml. Calculate the moles C12H22O12 percent in the mixed solution. Please provide steps
*February 17, 2010 by anonymous*

**science**

a student adds 3 spoons of salt to 100 ml of water. the solution is clear, with nothing on the bottom of the cup. one spoon of the slat ha a mass of 5g. what is the mass of the solution? after the water evaporates, what is the mass of the solid remaining in the cup?
*September 24, 2015 by linda*

**Chemistry **

In a titration of 35 mL of 0.40 M H3PO4 with 0.30 M KOH solution, what volume (in mL) of KOH solution is needed to reach the last equivalence point (i.e., point in the titration where enough KOH has been added to neutralize all three of the acidic protons in the phosphoric acid)?
*November 3, 2015 by Anonymous*

**1CHEM**

In a titration of 35 mL of 0.40 M H3PO4 with 0.30 M KOH solution, what volume (in mL) of KOH solution is needed to reach the last equivalence point (i.e., point in the titration where enough KOH has been added to neutralize all three of the acidic protons in the phosphoric acid)?
*November 3, 2015 by Anonymous*

**Chemistry **

In a titration of 35 mL of 0.40 M H3PO4 with 0.30 M KOH solution, what volume (in mL) of KOH solution is needed to reach the last equivalence point (i.e., point in the titration where enough KOH has been added to neutralize all three of the acidic protons in the phosphoric acid)?
*November 3, 2015 by Anonymous*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...
*November 29, 2013 by Katy*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...
*November 30, 2013 by Katy*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...
*November 30, 2013 by Katy*

**chemistry**

Select only the True statements about buffer systems. Select all that are True. 1. Starting with NH3(aq) and adding a small amount of HCl(aq) will make a buffered solution. 2. The blood buffer, among other things, is supported by carbonic acid and its conjugate base ...
*March 28, 2014 by bekah*

**Thin Layer Chromotography**

Can you use TLC to distinguish various isomers from one another? In what kind of substance can you NOT distinguish the isomers from each other? i think it is not possible to distinguish If I have an unknown sample containing several ketones and want to use TLC to identify the ...
*November 5, 2006 by Sarah*

**chemistry**

a new compound composed of just Hex-Nuts and bolts is formed.A 13.7 Kg sample of the new compound is separated into its component elements with the following result 3.84 kg. of hex-nuts and 9.90 kg of bolts. 1. How many hex-nuts are present in the 13.7 kg sample 2. how many ...
*October 10, 2012 by Amanda*

**chem**

a new compound composed of just Hex-Nuts and bolts is formed.A 13.7 Kg sample of the new compound is separated into its component elements with the following result 3.84 kg. of hex-nuts and 9.90 kg of bolts. 1. How many hex-nuts are present in the 13.7 kg sample 2. how many ...
*October 22, 2012 by Amanda*

**Statistics**

The Deborah Heart Institute performs many open-heart surgery procedures. Recently research physicians at the Institute developed a new heart bypass procedure that they believe reduces the average length of recovery. The hospital board will not adopt the procedure unless there ...
*April 4, 2012 by Richard*

**Calculus**

I need to find the exact solution to: 2sin2x = sqrt(x)on the interval (0,pi) This is how I started it, but I don't think it's correct. sin2x = sqrt(x)/2 2sinxcosx = sqrt(x)/2 sinxcosx = sqrt(x)/4 What do I need to do now? need to find the exact solution to: 2sin2x = sqrt(x)on ...
*August 21, 2006 by Jen*

**Chemistry**

Please help me answer this question; The goal of the recrystallization procedure is to obtain purified material with a maximized recovery. For each of the following, explain why this goal would be adversely affected. a) In the solution step, an unnecessarily large volume of ...
*February 8, 2010 by Judy*

**chemistry**

An aqueous salt solution is formed by adding 11.67 g sodium sulfate (solute) to water (solvent). What mass (in g) of water is used if the freezing point of the solution is -12.9 oF. Kf H2O = 1.86 oC/m I know to use delta T= i*Kf*m I then solve for m. But, then I'm confused on ...
*February 26, 2012 by Alyssa*

**Inorganic Chemistry**

In a constant-pressure calorimeter, 70.0 mL of 0.340 M Ba(OH)2 was added to 70.0 mL of 0.680 M HCl. The reaction caused the temperature of the solution to rise from 22.00 °C to 26.63 °C. If the solution has the same density and specific heat as water (1.00 g/mL and 4.184 J/g·K...
*March 11, 2016 by Michael*

**Inorganic Chemistry**

In a constant-pressure calorimeter, 70.0 mL of 0.340 M Ba(OH)2 was added to 70.0 mL of 0.680 M HCl. The reaction caused the temperature of the solution to rise from 22.00 °C to 26.63 °C. If the solution has the same density and specific heat as water (1.00 g/mL and 4.184 J/g·K...
*March 11, 2016 by Michael*

**chemistry**

In which of the following ways would you change the glass sample to make the ion exchange more efficient? a)Change the composition of the glass to increase the proportion of B2O3. b)Change the composition of the glass to add Na2O, Li2O, or MgO. c)Change the composition of the ...
*April 10, 2013 by Anonymous *

**statistics 2**

In Hamilton County, Ohio the mean number of days needed to sell a home is 86 days (Cincinnati Multiple Listing Service, April, 2012). Data for the sale of 40 homes in a nearby county showed a sample mean of 80 days with a sample standard deviation of 20 days. Conduct a ...
*September 23, 2014 by ANAHI*

**statistics 2**

In Hamilton County, Ohio the mean number of days needed to sell a home is 86 days (Cincinnati Multiple Listing Service, April, 2012). Data for the sale of 40 homes in a nearby county showed a sample mean of 80 days with a sample standard deviation of 20 days. Conduct a ...
*September 23, 2014 by MIA*

**Statistics 2**

In Hamilton County, Ohio the mean number of days needed to sell a home is 86 days (Cincinnati Multiple Listing Service, April, 2012). Data for the sale of 40 homes in a nearby county showed a sample mean of 80 days with a sample standard deviation of 20 days. Conduct a ...
*September 24, 2014 by Vanessa*

**statistics 2**

In Hamilton County, Ohio the mean number of days needed to sell a home is 86 days (Cincinnati Multiple Listing Service, April, 2012). Data for the sale of 40 homes in a nearby county showed a sample mean of 80 days with a sample standard deviation of 20 days. Conduct a ...
*September 24, 2014 by Vanessa*

**Physical Science**

1. Which equation correctly shows beta decay? (A) 210/82 Pb -> 209/81 Tl + 0/-1 e + y (B) 210/82 Pb -> 209/83 Bi + 0/-1 e + y (C) 210/82 Pb -> 210/83 Tl + 0/-1 e + y (D) 210/82 Pb -> 210/83 Bi + y (E) 210/82 Pb -> 210/83 Bi + 0/-1 e + y 2. The half-life if radon...
*November 18, 2013 by CJ*

**ap statistics**

Which of the following is not correct? A. The rejection region is controlled by the alpha level and the alternate hypothesis. B. The p-value measures the probability that the null hypothesis is true. C. The probability of a Type I error is controlled by the selection of the ...
*April 24, 2014 by cassandra*

**Chemistry**

When 0.5963g of a sample containing NaNO2 and some inert material is allowed to react with excess HSO3NH2, the volume of N2 gas produced is measured. The volume of N2 gas corrected to 298.15K and 100kPa is calculated to be 0.146L. Find the mass percent of NaNO2 in the sample ...
*May 25, 2011 by Mark*

**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 be dated accurately ...
*January 23, 2012 by L.Bianchessi*

**statistics**

A test of hypothesis is performed to determine whether the proportion of Montrealers (population 1) who want the decriminalization of marijuana is greater than the proportion of Torontonians (population 2) who want decriminalization of marijuana. A random sample of 115 ...
*March 27, 2015 by Anonymous*

**Algebra**

I'm not quite sure about these problems. I know how to do them, but it seems that I get the wrong answer. Maybe I'm supposed to get 'no solution' but I'm not sure. Could someone please help me with them? 5|6-5x|=15x-35 2|3x-7|=10x-8 1/4|4x+7|=8x+16 Ok for 5|6-5x|=15x-35 first ...
*September 14, 2006 by Maria*

**Chemistry**

Write the chemical formula for the simplest heptane isomer and give its name, b) give the names of two heptane isomers with hexane as the base chain, c) give the names of names of the five heptane isomers with pentane as the base chain, d) give the name of the isomer with ...
*March 24, 2012 by Hannah*

**Business Statistics**

Customers arrive at a movie theater at the advertised movie time only to find that they have to sit through several previews and prepreview ads before the movie starts. Many complain that the time devoted to previews is too long (The Wall Street Journal, October 12, 2012). A ...
*October 22, 2014 by Noah*

**chemistry**

A 1.50 liter gas sample at 745mm HG and 25 celsius contains 3.55% radon by volume radon-220 is an alpha emitter with a half life of 55.6 seconds. how many alpha particles are emitted in 5 minutes by this sample? I got an answer 1.59x10^19 I started at 745/760=.980263 then ....
*June 17, 2012 by Nancy*

**physics**

A 100 g aluminum calorimeter contains 250 g of water. The two substances are in thermal equilibrium at 10°C. Two metallic blocks are placed in the water. One is a 50 g piece of copper at 79°C. The other sample has a mass of 83 g and is originally at a temperature of 100°C. The...
*April 28, 2010 by Kelsey*

**science (chemistry)**

I have to do this lab where I titrate Na2CO3 with HCl dilute solution but i had to add Methyl orange indicator to the solution and im not sure what the endpoint is supposed to be colored, is it supposed to be orange or pink?? im confused and just how orange is it supposed to ...
*June 21, 2007 by christina*

**Physical Science**

24. What happens when a solution of nitric acid (HNO3) is added to a solution of potassium hydroxide (KOH)? What are the products? 25. Which of the following compounds can react with H2SO4 to form a salt: NaCl, Ca(OH)2, HF, AlCl3, H2O, Mg(OH)2? Name the salt(s) that would form...
*October 15, 2013 by Alexandra*

**Chemistry**

A student began adding titrant to the acid solution, but stopped when she suddenly realized that she forgot to add the 3 drops of phenolphthalein. When she did, the solution immediately turned dark red! What can the student do to correct this error and salvage this trial, so ...
*October 27, 2013 by Matt*

**chemistry**

how wold you prepare 2.00L of 1.00M HCl solution using 6.00 M HCl? i already found the volume of 6.00M HCl needed to be .333L. i am confused about how to actually prepare the solution. do i used a volumetric flask or any other glassware?
*February 26, 2011 by lindy*

**chemistry**

Calculate the percent ionization of a 0.15 formic acid solution in a solution containing 0.11 potassium formate. I have the formic acid Ka=1.8 *10^-4 When I solve for "x" I'm getting 1.1.44*10^-2 When I plug that into equation (x/0.15-x)*100, I'm getting 10.6% which is ...
*March 31, 2011 by redgy*

**calculus**

Solve the given equation. (Enter your answers as a comma-separated list. Let k be any integer. Round terms to three decimal places where appropriate. If there is no solution, enter NO SOLUTION.) sin θ cos θ − 2 sin θ = 0
*October 21, 2011 by stellar*

**Chemistry ammonia gas**

In an experiment i had a test tube with Ca(NO3)2 solution in it and I added NaOH and a piece of aluminium. After carefully heating the solution ammonia gas was formed Can you help me write the equation for the reaction? I don't know the other products just the ammonia gas ...
*October 29, 2008 by Marysia*

**Algebra**

A chemist has two solutions of sulfuric acid. The first is one half sulfuric acid and half water. The second is three-fourths sulfuric acid and one fourths water. He wishes to make 10 liters of a solution which is two-thirds sulfuric acid and one-thirds water. How many liters ...
*November 10, 2013 by Jane*

**social studies**

A poll of 700 persons attending the Taste of Chicago showed that 455 persons, 65% of the sample, believed that the food was overpriced. It is estimated that 1,250,000 persons attend the Taste. Statistics suggest that, although 65% plus or minus 5% of attendees believe that the...
*April 10, 2015 by phia*

**Chemistry**

Consider a solution containing 0.100M fluroide ions and 0.126M hydrogen fluroide. Calculate the concentration of fluoride ions after the addition of 5.00ml of 0.100M HCl to 25.0ml of this solution. a description as to how to get to the answer would be appreciated Use the ...
*March 29, 2007 by annonymous*

**math**

Describe two ways to determine whether or not a given point is a solution of a line. Which way is more accurate? Why? The only practical and fast way is to substitute the coordinates of the point into the equation. If the equation is "true", then it is a solution. Any other ...
*July 30, 2007 by heather*

**Chemistry**

Hi Can someone please help me undersand how to get the answer to this question A 15.0 mL solution of 0.050 mol/L AgNO3 was titrated with 0.0250 mol/L NaBr in the cell SCE || titrated solution | Ag(s) Find the cell voltage for 10.0 mL of titrant added. (a) -0.0312 V (b) 0.194 V...
*April 26, 2010 by James*

**Chem 112**

Calculate the pH of a buffer solution prepared by dissolving 0.12 mole of cyanic acid, HCNO and 0.65 mole of sodium cyanate, NaCNO in enough water to make 1.0 liter of solution. [Ka(HCNO) = 2.0 × 10-4] I know that this question has something to do with turning moles into ...
*March 21, 2011 by Bridget*

**Chemistry**

Acetic acid dissociates/ionizes itself as follows: CH3COOH(aq) ⇔ H+(aq) + CH3COO-(aq) If you add sodium acetate, CH3COONa, to the solution: a) a precipitate will be formed b) more acetic acid will be ionized c) the concentration of hydrogen ions will decrease d) the ...
*May 15, 2012 by Andrea*

**chemistry**

When 5.00 g of barium hydroxide are added to 250.0 mL of 0.250 hydrochloric acid in a calorimeter, the temperature off the solution increases from 25.0 C to 28.0 C. Calculate the enthalpy ( in kJ per mole of water) given the density of the hydrochloric acid is 1.01 g/mL and ...
*June 1, 2013 by Jen*

**Chemistry**

In a coffee cup calorimeter, 1.60 g of NH4NO3 is mixed with 75.0 g water at an initial temperature of 23.50 ºC. When the salt was completely dissolved, the solution temperature of the calorimeter became 21.80 ºC. Assume the solution’s specific heat capacity is 4.184 J/g. ºC. ...
*March 10, 2014 by Eddie*

**College Gen. Chemistry - Science**

You have 120.0 mL of a 0.245 M solution of NaCl in an open beaker. After several days, you test the solution and find that it now has a concentration of 0.348 M. How much water must have evaporated from the beaker given the new concentration?
*March 25, 2014 by Anonymous*

**Calculus**

Show that u(x, t) = f(x−ct)+g(x+ct), where c is a constant and f and g have continuous second derivatives, is a solution of the wave equation in one dimension, ie (∂t)^2 u = c^2 ∂x^2 u. Note that this solution to the wave equation consists of two functions ...
*September 30, 2015 by Margo*

**Chemistry**

Please check my work- what is the molarity of a solution that has 34.85 g of Potassium sulfate dissolved in one liter of solution? so K2(SO4) molar mass is 174.26, 34.85 grams x 1mol/174.26 than divided by 1 Liter equals .19998 Molarity with sig figs would it be .1999 or .2000?
*April 25, 2016 by Petey*

**STAT**

An independent-measures research study compares three treatment conditions with a sample of n = 10 in each condition. The sample means are M1 = 2, M2 = 3, and M3 = 7 a. Compute SS for the set of 3 treatment means. (Use the three means as a set of n = 3 scores and compute SS.) ...
*February 24, 2013 by Tracy*

**Chemistry**

A 0.10 M solution of a weak monoprotic acid has a hydronium-ion concentration of 5.0 ´ 10-4 M. What is the equilibrium constant, Ka, for this acid? a. 5.0 ´ 10-2 b. 5.0 ´ 10-3 c. 2.5 ´ 10-4 d. 2.5 ´ 10-5 e. 2.5 ´ 10-6 2. (Points: 1) What is the carbonate-ion, CO3-2, ...
*May 13, 2010 by write2khin*

**Algebra**

A chemist mixed some 20% peroxide sol with some 30% peroxide sol to make 500ml of a 25% peroxide solution.How many ml of each solution should be used? HELP just cannot get this one..
*November 9, 2008 by S.G*

**Algebra**

How do I set up and solve this problem? 100% acid is to be added to 10% acid solution to obtain 90 liters of 48% solution. (a) What amount of 100% of acid should be used? (b) What amount of 10%?
*May 1, 2012 by Taurus*

**Chemistry help pls helppppp**

What volume of a solution that is 15.7 % (w/w) lolinic acid (density = 1.64 g/mL) contains 4.25 g of lolinic acid? What is the molarity of a 20.2 % (w/w) solution of rossonic acid (423.6 g mol-1) that has a density of 1.78 g mL-1?
*January 31, 2014 by nene *

**chemistry**

You need 715 mL of a 45% alcohol solution. On hand, you have a 55% alcohol mixture. How much of the 55% alcohol mixture and pure water will you need to obtain the desired solution?
*October 18, 2014 by Gotti*

**Math**

The owner of a large company is conducting a survey about job satisfaction, including questions about salary, hours, stress, and other conditions. There are about 800 employees in the company, including 100 executive positions, 650 middle-management positions, and 50 custodial...
*August 7, 2012 by Fatima*

**Statistics**

Total plasma volume is important in determining the required plasma component in blood replacement theory for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that sample of 50 male firefighters are ...
*June 24, 2010 by stan*

**Statistics**

Total plasma volume is important in determining the required plasma component in blood replacement theory for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that sample of 50 male firefighters are ...
*June 25, 2010 by stan*

**Chemistry**

What does ammonia have anything to do with bogdan's rocket building? -can't find this anywhere if we had to order ammonia we don't order in pure. it is ordered in clandestine, liquid solution. the ammonia exists in this aq solution in eq. what is the eq equation?include a heat...
*October 27, 2008 by Xi*

**Chemistry**

What does ammonia have anything to do with bogdan's rocket building? -can't find this anywhere if we had to order ammonia we don't order in pure. it is ordered in clandestine, liquid solution. the ammonia exists in this aq solution in eq. what is the eq equation?include a heat...
*October 27, 2008 by Xi*

**chemistry 112**

A volume of 60.0mL of aqueous potassium hydroxide (KOH) was titrated against a standard solution of sulfuric acid (H2SO4). What was the molarity of the KOH solution if 19.2mL of 1.50 M H2SO4 was needed? The equation is 2KOH(aq)+H2SO4(aq)→K2SO4(aq)+2H2O(l) Express the ...
*October 7, 2014 by Sam*

**Chemistry**

The molarity of H3PO4 is .01 M. The density of the H3PO4 in the solution is .0009 g/mL. What is the mass percent of H3PO4 in the solution, which has a density of 1.11 g/ml?
*February 18, 2014 by Anonymous*

**chemistry solution preparations**

how can we prepare 0.5 n solution of hcl as we have 37% hcl and 0.1n hcl. and we want to make 0.5n hcl from 0.1n hcl by pouring 37% hcl?
*July 7, 2014 by asif*

**Biology**

You need to prepare a 0.25 M solution of NaCl but you only need 50 ml of this solution. How many grams of NaCl would you need?
*January 15, 2015 by Anonymous*

**Algebra**

How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the remaining solution contains 16% peroxide?
*September 15, 2015 by Anonymous*

**Statistics**

Based on information from Harper's Index, 37 out of a random sample of 100 adult Americans who did not attend college believe in extraterrestrials. However, out of a random sample of 100 Americans who did attend college, 41 claim that they believe in extraterrestrials. At the ...
*April 23, 2013 by Torri*

**AP Chemistry**

A mixture of 20.0 grams of CaO and BaO is placed in a 12.5 L vessel at 200oC with excess CO2 . The mixture is allowed to react to completion forming CaCO¬3 and BaCO3 .The pressure in the container after reaction is 220 torr. The solid carbonates are neutralized by adding 650.0...
*January 3, 2015 by Jim*

**Grade 12 chemistry**

This is the second reaction: HCl(aq)+NaOH(aq)-->NaCl(aq)+H2O(l) (Heat of neutralization) This reaction involves mixing two solutions: 1.00 mol/L NaOH and 1.00 mol/L HCl. Trial 1: 48.0 mL of the NaOH solution is mixed with 47.5 mL of the HCl. The temperature rises from 22.00...
*January 1, 2012 by tessa*

**Chemistry please check!**

A 0.21g sample of sulfuric acid is dissolved completely in sufficient water to make 0.25 litre of final solution. Calculate the hydrogen ion concentration in mol1-1 in this solution and show successive steps in the calculation: If 0.21g in 0.25l then 0.84g in 1l. Add together ...
*March 9, 2007 by Hol*

**Chemistry, pH, Buffers**

Please help!! Given this data: mass of unknown acid 1.4671g Volume of NaOH used in titration 18.47mL Concentration of the NaOH used 0.2403M pH of the original acid solution 2.16 pH of the final acid solution 3.49 Show me how do I calculate the Ka of the unknown acid and the ...
*April 2, 2012 by Krina*

**chemistry**

Two aqueous solutions of sucrose, C12H22O12, are mixed. One solution is 0.1495 M sucrose and has d = 1.018 g/mL; the other is 12.00 % sucrose by mass and has d = 1.038 g/ml. Calculate the moles C12H22O12 percent in the mixed solution. Please provide steps 100 mL for each soln.
*February 17, 2010 by anonymous*

**Physics**

A)What mass of silver chloride can be produced from 1.33 of a 0.207 solution of silver nitrate? I got this one, its 39.4 g B)The reaction described in Part A required 3.28 of potassium chloride. What is the concentration of this potassium chloride solution? I keep getting 0.08...
*October 14, 2011 by Kristi*

**Chemistry**

A)What mass of silver chloride can be produced from 1.33 of a 0.207 solution of silver nitrate? I got this one, its 39.4 g B)The reaction described in Part A required 3.28 of potassium chloride. What is the concentration of this potassium chloride solution? I keep getting 0.08...
*October 14, 2011 by Kristi*

**math**

a college lab paced two orders with a chemical supplier. the first order was for 13 bottles of calcium hydroxide solution and 4 bottles of sulfuric acid and totalled $ 487. the second order was for 6 bottles of calcium hydroxide solution and 2 bottles of sulfuric acid and ...
*October 20, 2011 by patel*

**math**

a college lab paced two orders with a chemical supplier. the first order was for 13 bottles of calcium hydroxide solution and 4 bottles of sulfuric acid and totalled $ 487. the second order was for 6 bottles of calcium hydroxide solution and 2 bottles of sulfuric acid and ...
*October 20, 2011 by patel*

**Math**

A pathologist, trying to identify a bacterial infection, places a sample in a growth chamber and measures 1000 bacteria at the end of day 5 of the test. From daily measurements, the growth rate of the number of bacteria is determined to be 5% per day. Note that: A linear ...
*October 25, 2011 by Matt*

**chemistry**

1. Would it be advisable to determine the freezing point of pure p-dichlorobenzene with one thermometer and the freezing point of the solution with a different one? Explain. 2. If 0.150 mole of a nonvolatile non-electrolyte solute is present in 1200g of water, what are the ...
*February 2, 2012 by Larry*

**Chemistry**

1. Would it be advisable to determine the freezing point of pure p-dichlorobenzene with one thermometer and the freezing point of the solution with a different one? Explain. 2. If 0.150 mole of a nonvolatile non-electrolyte solute is present in 1200g of water, what are the ...
*February 19, 2016 by Allie*

**Chemistry **

Can someone please check my work? Calculate the mass of (NH4)2S2O8 needed to prepare 250mL of a 0.100M solution. I got 5.705 g. Calculate the volume of 2.00M KI needed to prepare 250mL of a 0.200M solution. I got 0.025L or 25mL. Calculate the volume of 0.100M Na2S2O3 needed to...
*January 22, 2011 by Rachel*

**Math**

In order to estimate the mean amount of time computer users spend on the internet each month, how many computer users must be surveyed in order to be 95% confident that your sample mean is within 11 minutes of the population mean? Assume that the standard ...
*May 17, 2016 by John*

**Chemistry**

The formate ion, (CHO2-), is related to the acetate ion and forms ionic salts with many metal ions. Assume that 9.7416 g of M(CHO2)2 (where M represents the atomic symbol for a particular metal) are dissolved in water. When a solution of 0.200 M sodium sulfate is added, a ...
*September 19, 2014 by Aaron*

**Chemistry**

The formate ion, (CHO2-), is related to the acetate ion and forms ionic salts with many metal ions. Assume that 9.7416 g of M(CHO2)2 (where M represents the atomic symbol for a particular metal) are dissolved in water. When a solution of 0.200 M sodium sulfate is added, a ...
*September 19, 2014 by Aaron*