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January 30, 2015

Search: 355g sample of a saturated solution of KNO3

Number of results: 26,626

chemistry
In a 100g sample of copper, 69 g were Cu-63 while 31g were Cu-65. Find the average atomic mass.
October 14, 2012 by Kevin

chemistry
50 ml of Argon is collected at 60.0 degree C and 820.0 torr how much this sample weigh in grams?
November 24, 2012 by Andrew78

Chemistry
What is the molar mass of a compound if a gaseous sample has a density of 2.807 g/L at 18 °C and 728 torr?
December 1, 2012 by Joe

Chemistry
What is the molar mass of a compound if a gaseous sample has a density of 2.807 g/L at 18 °C and 728 torr?
December 1, 2012 by Sarah

Chemistry
What volume a sample of 67.0 grams of nitrogen gas (N2)will occupy at -25degrees C and 3 atm pressure?
December 2, 2012 by malina

chemistry
The half life of gold-197 is 10.6. What fraction of a sample remains after 21.2 years?
January 9, 2013 by Evelyn

Chem.
What is the mass (in kilograms) of a cube of silver that measures 0.68 on each side, when the density of the sample is 10.5g/cm3
January 20, 2013 by nick

chemistry
if a 3.72 gram sample of nitrogen occupies a 2.50 liter container at 1.08 atm, what is the temperature in Celcius?
January 24, 2013 by jessica

science
Calculate the fraction of atoms in a sample of argon gas at 365 K that has an energy of 11.0 kJ or greater.
February 9, 2013 by Hannah

Chemistry
How much heat is necessary to change a 52.0 g sample of water at 33.0 C into steam at 110.0 C?
February 12, 2013 by E

Chemistry
How much heat is necessary to change a 52.0 g sample of water at 33.0 C into steam at 110.0 C?
February 12, 2013 by E

Science
If the half-life of a radionuclide is 1 month, is a sample of it completely decayed after 2 months?
March 22, 2013 by Dee

chemistry
What is the specific heat of an unknown substance if a 2.53 g sample releases 13.1 cal as its temperature changes from 25.5°C to 21.3°C?
April 17, 2013 by ching chong

Chemistry
How much heat needs to be released if 95g sample of ethyl alcohol condenses?
April 17, 2013 by Patti

statistics
A random sample of 100 of a population Mean is 31 and standard deviation 22 Approximate probability of 28
April 27, 2013 by Dorri

CHEM
IF A 50.0 ML SAMPLE OF CALCIUM HYDROXIDE IS TITRATED WITH 25.0 ML OF 0.200M PHOSPHORIC ACID, WHAT IS THE MOLARITY OF THE BASE?
May 7, 2013 by SHANNA

science
How can you attempt to control for any extraneous variables within a sample experiment on prayer and healing?
May 23, 2013 by mordagow

math
1. A sample of n=20 has a mean of M = 40. If the standard deviation is s=5, would a score of X= 55 be considered an extreme value? Why or why not?
July 1, 2013 by susan

7th grade Math
If there is a population of 800 deer what would be a good sample size and why.
September 6, 2013 by Brandi

Chemistry
A 85.2-mg sample of the compound X4O10 contains 48.0 mg of oxygen atoms. What is the atomic mass of element X?
February 6, 2014 by College

CHEMISTRY
A 85.2-mg sample of the compound X4O10 contains 48.0 mg of oxygen atoms. What is the atomic mass of element X?
February 6, 2014 by College

College Chemistry
If a 375 mL sample of water was cooled from 37.5°C to 0°C, how much heat was lost (in joules)
February 19, 2014 by Esther

Chemistry
A 3.68 g sample of solid gold is heated from 24 ºC to 34 ºC. How much energy (in joules and calories) is required? Thank you!
March 7, 2014 by Eddie

Business and Economics
The weights (in grams) of the contents of several small bottles are 8, 4, 3, 6, 7, 1 and 5. What is the sample variance? 5.81 4.33 5.67 2.22
March 27, 2014 by Anonymous

science
The volume of 3.96 g of a gas sample at standard conditions it was found to be 1.15 L.Calculate its molecular mass?
April 13, 2014 by Jaco

chemistry
determine the % of water of crystallization in pure sample of green vitriol (FeSo4.7H2O)
June 30, 2014 by shashank

Math
Determine whether a correlation coefficient of r = 0.471 is significant at the 5% level for a sample size of 20.
July 12, 2014 by Shelagh

chem
How many moles of carbon, hydrogen, and oxygen are present in a 100-g\rm g sample of ascorbic acid?
July 20, 2014 by helen

chem
How many moles of carbon, hydrogen, and oxygen are present in a 100-g\rm g sample of ascorbic acid?
July 20, 2014 by helen

Statistics
A sample of n=20 has a mean of M = 40. If the standard deviation is s=5, would a score of X= 55 be considered an extreme value? Why or why not?
November 9, 2014 by Terri

general chemistry
what is the % acid (eq wt=173.8) if 20.07 mL of .1100 N base were required to neutralize .7231 g of sample?
December 8, 2014 by alysia

chemisry
A 0.1 molal solution of a weak monoprotic acid was found to depress the freezing point of water 0.1930C. Determine the Ka of the acid. You can assume 0.1 molal and 0.1 molar are equivalent. 100 ml of a 0.1M solution of the above acid is titrated with 0.1 M NaOH. After an ...
February 12, 2012 by ashley

math
For a certain experiment, a student requires 100 cubic centimeters of a solution that is 8% HCI. The storeroom has only solutions that are 15% HCI and 5% HCI. How many cubic centimeters of each available solution should be mixed to get 100 cubic centimeters of 8% HCI?
August 17, 2010 by Mary

chem
When saccharin is added to pure water, the freezing point of the resulting solution drops to -5.0C, Calculate the freezing point depression of the aqueous saccharin solution. Note: freezing point of pure water is O.0C... Stuck thanks so much!
January 16, 2013 by Lala

chemistry
calculate the change in pH when 9.00ml of 0.100M HCl(aq) is added to 100.0mL of a buffer solution that is 0.100M in NH3(aq) and 0.100M NH4Cl(aq). ...Calculate the change in pH when 9.00,L if 0.100M NaOH(aq) is added to the original buffer solution.
October 28, 2012 by mike

science, chemistry
OBJECTIVE: to find out which of two indicators, methyl orange or phenolphthalein, gives more reliable and consistent results in the titration of H3PO4 with NaOH. REQUIREMENT: (1). Phosphoric acid solution of unknown concentration. (2). Standard NaOH solution. (3). Methyl ...
November 5, 2014 by elijah

Algebra
Devin attempted to solve the inequality -2x+6>10 following the steps below: •subtract 6 from both sides of the inequality. •divide both sides of the inequality by -2. He finds that x>-2. Clearly explain why this is not a correct solution. In your response, be sure to ...
April 20, 2012 by Nicole

chemistry
The freezing point of a 0.010 m aqueous solution of a nonvolatile solute is ?0.072°C. What would you expect the normal boiling point of this same solution to be? have no clue, thanks for the thelp Freezing point depression= N*kf* molality you have freezing point depression, ...
December 5, 2006 by tyler

Algebra, Please Help!
Devin attempted to solve the inequality -2x+6>10 following the steps below: •subtract 6 from both sides of the inequality. •divide both sides of the inequality by -2. He finds that x>-2. Clearly explain why this is not a correct solution. In your response, be sure to ...
April 20, 2012 by Nicole

Chemistry
After adding a hot piece of titanium to a cup containing 300.0 mL of 30.0 °C water, the final temperature of the solution is 41.2 °C and the final volume of the solution is 400.0 mL. The density of titanium is 4.50 g/cm3. If no energy is lost to the surroundings, what was the ...
December 11, 2014 by Laura

Chemistry HELP ASAP
A Gouy balance is used to determine the magnetic susceptibility of a substance. A strong electromagnet is placed next to the sample, which is on a balance. If the sample is paramagnetic, the mass reading of the balance will increase when the field is switched on. Based on ...
November 5, 2012 by Anonymous

Chemistry
In each of the following, determine how much solute (in g or mL) must be added to the correct quantity of water to make the given amount of solution at the correct concentration. a)KI to make 50.0mL of a 0.50 M solutioon b)12.0 M HCL to make 500 mL of a 1.0 M HCl c)Sucrose (...
May 2, 2010 by Kim

Chemistry
A 0.753 m solution of the solute CH3CN dissolved in the solvent C6H6 is available. Calculate the mass ( g ) of the solution that must be taken to obtain 3.274 mol of CH3CN. Additional info: Molar Mass (g/mol) CH3CN 41.05 C6H6 78.11 Density ( kg/L ) CH3CN 0.7857 C6H6 0.8786 ...
May 8, 2010 by Kyo

Chemistry
1.a solution that is 6.5×10−2M in potassium propionate C_2 H_5 COOK or KC_3 H_5 O_2 and 8.5×10−2M in propionic acid C_2 H_5 COOH or HC_3 H_5 O_2 what is the ph? 2.a solution that is 8.0×10−2M in trimethylamine, CH_3 _3 N, and 0.10M in trimethylammonium ...
November 22, 2012 by Josh G.-Happy Thanksgiving

Chemistry
1.a solution that is 6.5×10−2M in potassium propionate C_2 H_5 COOK or KC_3 H_5 O_2 and 8.5×10−2M in propionic acid C_2 H_5 COOH or HC_3 H_5 O_2 what is the ph? 2.a solution that is 8.0×10−2M in trimethylamine, CH_3 _3 N, and 0.10M in trimethylammonium ...
November 23, 2012 by Josh G.-Happy Thanksgiving

Chemistry/Redox Reactions
An electrochemical cell consists of a nickel metal electrode immersed in a solution with [Ni2+] = 1.0 M separated by a porous disk from an aluminium metal electrode immersed in a solution with [Al3+] = 1.0 M. Sodium hydroxide is added to the aluminium compartment causing Al(OH...
August 18, 2008 by Hanna

chemistry
When 0.320 moles of NH4Cl is dissolved in 1.00 L of water, the temperature drops by 13.7 degrees C. What is the heat of solution of ammonium chloride? The solution has a density of 1.0012 g/mL and a specific heat of 0.9818 cal/g degrees C. How do you find the mass of water to ...
April 7, 2010 by anita

chemistry
What is the total vapor pressure4 at 20° C of a liquid solution containing 0.30 mole fraction benzene, C6H6, and 0.70 mole fraction toluene, C6H5CH3? Assume that Raoult’s law holds for each component of the solution. The vapor pressure of pure benzene at 20° C is 75 mmHg; that...
September 14, 2010 by Tim

chemistry (Pls Bob check for me)
A 150mg/dl glucose solution was diluted 1:2. Then 0.5ml of it was added to 4.5ml saline. 2ml of this solution was diluted to 10ml. What is the final concentration of glucose? 1L = 10dL 1dL = 100mL My own calculation 150mg/dL = 150mg/100ml =1.5 150mg/100ml x 1/2 x 1/10 x 1/5 1....
March 16, 2013 by Fai

Chemistry-dilutions
I have a 2000ppm benzoic acid solution.I want to prepare a 20ppm benzoic acid solution.Is it better to 1) do serial dilutions i.e. from 2000 to 200 to 20ppm or 2) prepare 20ppm standard fresh when required( take 10ul of 2000ppm stock and top up to 1ml in a LC vial with 990ul ...
September 11, 2010 by chloe

Chemistry
when pure sodium hydroxide is dissolved in water , heat is evolved in a laboratory experiment measure a molar heat of solution of sodium hydroxide the following procedure was followed. to a calorimeter containing 300g of water at 20.0 C and 10.65g of NaOH also at 20.0 C was ...
March 23, 2007 by jim

Chemistry
I did an experiment on Buffers: In a polystyrene beaker, mix 20 ml of 0.1M Acetic acid ad 25 ml of 0.1 M sodium acetate and immediately measure the pH. Remove the electrode and add 5 ml of 0.1 M HCL to this buffer. Stir the solution and measure the pH. This is my data: Conc.of...
July 16, 2009 by Saira

chemistry
– (b) Which are likely to have much lower critical micelle concentrations? (c) Which ... (e) You wish to use a solution of this surfactant in water to dissolve oil. Which region will be required to do this? (f) How much oil will dissolve in the surfactant-water solution if the...
January 13, 2013 by Anonymous

chemistry
1. Calculate pH of an acetate buffer containing 27.5 mM acetic acid (pKa is 4.74) and 50 mM sodium acetate. When a 30 mM aq solution of sodium acetate was prepared in the lab it had a pH of 8.8. Calculate the amount of acetic acid (in g) to be added to 0.5 L of this sodium ...
April 12, 2014 by Nick

Chemistry
Calculate pH of an acetate buffer containing 27.5 mM acetic acid (pKa is 4.74) and 50 mM sodium acetate. When a 30 mM aq solution of sodium acetate was prepared in the lab it had a pH of 8.8. Calculate the amount of acetic acid (in g) to be added to 0.5 L of this sodium ...
April 12, 2014 by Sarah

statistics
Two-sample Non-parametric Test Now, we examine the relationship between cry time and group among infants at Northbay. 1. Suppose we wish to perform a two-sample test, but we do not want to make any normality (or other strong parametric) assumptions. Conduct an appropriate non...
January 14, 2013 by Anonymous

Math
Can someone please help me with these three question? I having a very difficlut time answering them May first question To select a _________ sample, the population is divided into disjoint subgroups according to some characteristics like income level, and then a few ...
February 26, 2011 by Latisha

Math 3371
In a certain year, 26% of all teenagers in the United States had checking accounts. Your bank, TeenChex Inc., is interested in targeting teenagers who do not already have a checking account. (a) If TeenChex selects a random sample of 3,000 teenagers, what number of teenagers ...
November 24, 2014 by John

Chemistry
What is the final concentration (M) of a solution prepared by diluting 50.0 mL of a 6.00 M KCl solution to a volume of 0.500 L? A. 1.67 B. 0.600 C. 0.0167 D. 3.0 E. none of these My initial thought was to take the 6.00 M KCl/0.500 L, for an answer of 12. This baffles me that ...
November 21, 2009 by Coug

Chemistry
Acetic acid is a polar molecule and can form hydrogen bonds with molecules. Therefore, it has a high soulubility in water. Yet acetic acid is also soluble in benzene (C6H6), a nonpolar solvent that lacks the ability to form hydrogen bonds. A solution of 3.8g of CH2COOH in 80 g...
October 18, 2010 by Karly

Algebra
The area of a rectangular athletic field is represented by the expression square meters. Write an algebraic expression to represent one possible set of dimensions (in the sense Òlength times widthÓ) of the athletic field. Include correct units with your solution. The answer I...
November 4, 2010 by Jordyn

Chemsitry
Tris is an abbreviation for tris (hydroxymethyl) aminomethane, which is a weak base. Calculate how many grams of tris (mw=121.14g/mol) are needed to make 25mL of 0.10M tris solution. Calculate how many mL of 0.25M HCl are needed to convert half of the moles of tris present in ...
April 2, 2012 by Cassandra

Chemistry
30g of the palm shell were mixed with 15ml H3PO4 and 100ml of distilled water in a 250ml conical flask.The concentration of H3PO4 solution was 2.2M, from question,how to prepare those from ortho phosporic acid (98g/mol).Do help me, is it need to make a stock solution first and...
February 1, 2013 by Merlina_Lyn

chemistry
a. A 0.1 molal solution of a weak monoprotic acid was found to depress the freezing point of water 0.1930C. Determine the Ka of the acid. You can assume 0.1 molal and 0.1 molar are equivalent. b. 100 ml of a 0.1M solution of the above acid is titrated with 0.1 M NaOH. After an...
February 12, 2012 by billy

Physics. Urgent help!!
The relative humidity is 55% on a day when the temperature is 30.0°C. Using the graph below, determine the number of moles of water vapor per cubic meter of air. on the graph, Vapor pressure of water is on the y-axis and temperature on the x-axis 30C cordinates with 4200 Pa of...
April 25, 2007 by Papito

Chemistry
Galena(PbS) and cerussite(PbCO3)are two ores of lead. A mining company is considering which of these two ores to use for the extraction of lead. The equations for the reactions occurring are process using galena: 2PbS+3O2 ---> 2PbO+2SO2 2PbO+C ----> 2Pb+CO2 Process using...
April 23, 2013 by Qindan

Chemistry
Regarding conductivity: 1. If a solution has a high conductivity, it indicates that there are a lot of __________________ in solution. [Answer: ions] 2. Pure acetic acid does not conduct electricity, nor does pure water, but a mixture of the two does conduct. This is explained...
November 24, 2009 by .

chemistry
A solution was made by dissolving 5.15 mg of hemoglobin in water to give final volume of 1.00 mL. The osmotic pressure of this solution was 1.97 x 10^-3 atm at 25C. Calculate the molar mass of hemoglobin. pi = iMRT i = 1 since hemoglobin is nonelectrolyte and doesn't ...
September 14, 2012 by Wiped Out

College Chemistry
please help! You are given an unknown, colorless, solution that may contain only one salt from the following set: NaA, NaB, NaC. In solution each salt dissociates completely into the Na+ ion and the anion A-, B-, or C-, whose properties are A is green, B is yellow, and C is ...
November 10, 2010 by Marcus

intro to probability
In a study of particulate pollution in air samples over a smokestack, X1 represents the amount of pollant per sample when a cleaning device is not operating, and X2 represents the amount per sample when the cleaning device is operating. Assume that (X1, X2) has a joint ...
April 20, 2008 by amelie

chemistry
2KI+Pb(NO3)2=2KNO3+PbI2 suppose a solution containing 1.25g of KI is combined with a solution containing 2.42g Pb(NO3)2 _what mass of the yellow PbI would result what is the limiting reactant How much in grams of the excess reactant was used how much in grams of the excess ...
February 10, 2013 by may

college Chemistry
What is the mole of oxalic acid? Equation:H2C2O4 + 2NaOH---> Na2C2O4 + 2H2O *Moles of oxalic acid dihydrate is 0.032 mole. * Molarity of oxalic acid solution is 0.128 M oxalic acid solution. * Initial volume of Oxalic acid is 19.8 ml and Final volume is 23.0 ml
December 6, 2010 by Ivy

Stats
The Internal Revenue Service (IRS) provides a toll-free help line for taxpayers to call in and get answers to questions as they prepare their tax returns. In recent years, the IRS has been inundated with taxpayer calls and has redesigned its phone service as well as posted ...
December 7, 2014 by Avery

College Chemistry
Sodium hydroxide is used extensively in acid-base titrations because it is a strong inexpensive base. A sodium hydroxide solution was standardized by titrating 27 mL of 0.1628 M standard hydrochloric acid. The initial buret reading of the sodium hydroxide was 2.44 mL, and the ...
October 3, 2010 by KELLY

statistics
Statistical Abstracts (117th edition) provides information aboutthe number of registered automobiles, including taxis, by state. The number ofregistered automobiles per 1,000 residents follows an approximately normaldistribution with mean ì = 514.6 and standard deviation ó = ...
April 19, 2012 by Anonymous

ALGEBRA
There is 117 grams (g) of acid in 900 g of a solution of acid and water. What percent of the solution is acid? 177/900=R/100 R*900=177*100 R=17,000/900 R=19.667 I WOULD ROUND THAT TO 20% SO R =20% AM I CORRECT IF NOT PLEASE EXPLAIN WHAT I DID WRONG Yes, that is correct.
March 31, 2007 by TOMMY

Inequality
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 23, 2007 by Liz

math
Determine all the possible values of x where 0 deg is more than or equal to x and x is more or equal to 360 deg such that i'm not sure the solution, please correct it, sin x sec x - 3 sin x = 0 the solution: sin x 1/cos x - 3 sin x = 0 sin x - 3 sin x = cos x then i don't know...
April 15, 2013 by choi2463

stats 2
3. Piyush, who had joined the infrastructure department of the bank, was asked to estimate the rental value of commercial property at Ranchi, for the purpose of identifying suitable premises for locating a new branch. Piyush assessed the standard deviation of the value of the ...
March 29, 2011 by prakash

organic chemistry
suppose solute A has a partition coefficient of 4.0 between diethyl ether and water. Demonstrate that if 100mL of solution of 5.0g of A in water were extracted with two 25mL portion of diethyl ether, a smaller amount of A would remain in the water than if the solution were ...
February 24, 2011 by Krystal

statistics
What is the formula to do this exercise, Please. A sample of 40 investment customers serviced by an account manager are found to have had an average of $23,000 in transactions during the past year, with a standard deviation of $8500. A sample of 30 customers serviced by ...
August 9, 2009 by Maggy

Math
The null and alternate hypotheses are: H0: π1 ≤ π2 H1: π1> π2 A sample of 100 observations from the first population indicated that X1 is 70. A sample of 150 observations from the second population revealed X2 to be 90. Use the .05 significance ...
July 24, 2012 by John

Statistics
Which of the following statements are true about matched pairs analysis? I. In a matched pair analysis you use a single-sample procedure. The sample is made up of the difference between pairs of observations. II. In a matched pairs analysis the two original samples are said to...
January 12, 2013 by Meow

chemistry
Magnesium reacts with HCl to produce magnesium chloride and hydrogen gas. Mg(s)+2HCl(aq)->MgCl2(aq)+H2(g). What is the molarity of the HCl solution if 330 ml of the HCl solution reacts with magnesium to produce 7.40 L of H2 gas measured at STP?
October 9, 2010 by Dana

CHEMISTRY
How do you get the concentration with buret readings? What would the concentration of HC2H3O2 (M) be? For example, Molarity of the NaOH solution: 0.2619 M Final buret reading: 31.10 ml Initial buret reading: 0 Volume of NaOH solution: 31.0 ml concentration of HC2H3O2 (M...
March 20, 2013 by Anna

Math
According to CTIA-The Wireless Association, the mean monthly cell phone bill in 2004 was $50.64. A market researcher believes that the mean monthly cell phone bill is different today, but is not sure whether bills have declined because of technological advances or increased ...
November 29, 2010 by Kris

chem
A voltaic cell consists of a strip of cadmium metal in a solution of Cd(NO3)2 in one beaker, and in the other beaker a platinum electrode is immersed in a NaCl solution, with Cl2 gas bubbled around the electrode. A salt bridge connects the two beakers. Write the equation for ...
April 13, 2013 by sarah

chemistry
Water in contact with air is acidic due to the dissolved carbon dioxide. Water in equilibrium with the air contains 4.4 x 10^-6% CO2. The resulting carbonic acid, H2CO3,gives the solution a hydrogen ion concentration of 2.0 x 10^-6M, about 20 times larger than that of pure ...
March 24, 2007 by Heather

CHEMISTRY
Not for homework, just practice problems I'm having trouble with. Knowing that one mole of KHP, C8H5O4K, reacts with one mole of NaOH, what mass of KHP is required to neutralize 30.0 mL of the 0.10 M NaOH solution? if 24.5 mL of the 0.10 M NaOH solution is required to reach ...
October 22, 2012 by Kimberly

chemistry who step by step for me
1.2g mixture of na2c03 and k2c03 was dissolved in water to form 100cm3 of solution, 20 cm3 of this solution required 40cm3 of 0.1 hcl for neutralization. Calculate the weight na2c03 and k2c03 in the mixture? My calculation 20cm3/100cm3 = 0.2 x/53 + (0.2g-X) + y/69 = 0.004 0....
June 22, 2014 by ken

Chemistry
What is the mole of oxalic acid? Equation:H2C2O4 + 2NaOH---> Na2C2O4 + 2H2O *Moles of oxalic acid dihydrate is 0.032 mole. * Molarity of oxalic acid solution is 0.128 M oxalic acid solution. * Initial volume of Oxalic acid is 19.8 ml and Final volume is 23.0 ml
December 7, 2010 by Ivy

Chemistry
My lab had done protein crystallography with lysozyme. Two solutions were used to prepare the crystallization: lysosome solution and the precipitate solution. 1) There was a distinct amount of starting material in a well. what would that do to the size of the crystals if the ...
October 11, 2014 by Anonymous

OChem
A sample of limonene has a specific rotation of +81.5. (Given that R-(+)-limonene = +125.5 and, S-(-)-limonene = -122.1). What is the %ee? ______%ee What is the molecular composition of this same sample? S isomer = ______% R isomer = ______% This is how I solved for the R and ...
November 2, 2011 by Susie

Chemistry
The enthalpy of solution of CaCl2 is -82.88kJ. If the specific heat of the solution is 4.184J/g*C and the calorimeter constant can be neglected, what will be the final temperature after 5.36g of CaCl2 is dissolved in 100.0g of H2O at 25.0C? I assume the enthalpy given is kj/...
May 20, 2007 by Em

Chemistry/pH- Weak Acid
Hi again! I have a new question, Can you help me? Consider 50.0 mL of a solution of a weak acid HA (Ka = 1.00.E-6), which has a pH of 4.000. What volume of water must be added to make the pH = 5.000? My Calculations: To calculate the concentration of x, I take the pH value -&...
August 17, 2008 by Mary

Chemistry
In a chromatography experiment, a solution was prepared by mixing 12.98 mg of isopropanol plus 10.00 mL of an unknown containing some acetone, and diluting to 25.00 mL. Signal of 5.97 and 6.38 were observed for the acetone and isopropanol, respectively. In an earlier ...
December 13, 2011 by Ken

STATISTICS
In a cross-sectional study of heart disease and gender in middle-aged men and women, 10% of men in the sample had prevalent heart disease compared with only 5% of women in the sample. After adjusting for age in multivariate logistic regression, the odds ratio for heart disease...
August 6, 2013 by Susie

Algerbra
Q1. Solve the system of equationd by addition method. -2x+y=6 -3x-4y=20 Select the correct choice below and, if necessary, fill in the answer box to comlete your choice a)The solution is__(simplify your answer. type an ordere pair) b) Infinitely many solutions c) No Solution ...
November 6, 2011 by Zedrick Dandridge

Statistics
A study of two groups of children since early childhood: One group of 62 attended preschool. A control group of 61 children from the same area and similar backgrounds did not attend preschool. Over 10 year period as adults, 38 of the preschool sample and 49 of the control ...
April 8, 2013 by Jose

ap stats
two different sections of electricians took their state license test. the first section consisted of 75 applicants having an average score of 262 and a sample standard deviation of 35. they were journeyman, experienced electricians who were renewing their licenses. the second ...
May 13, 2014 by emma

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