Number of results: 32,117

**Math Help Plz fast**

13. Describe the number of solutions for the equation. 10(x-2)=10x A.) one solution B.) no solution C.) infinite solutions*** 14. Describe the number of solutions for the equation. -2(y-3)=2y-6 A.)one solution B.)no solution*** C.)infinite solutions 18. Solve b-9>20. I don'...

*February 8, 2016 by Aaliyah*

**chemistry**

Calculate the pH values and draw the titration curve for the titration of 500 mL of 0.010 M acetic acid (pKa 4.76) with 0.010 MKOH. Calculate the pH of the solution after 490 mL of the titrant have been added. Calculate the pH of the solution after 500 mL of the titrant have ...

*January 31, 2017 by Jasmine*

**chemistry**

Calculate the pH values and draw the titration curve for the titration of 500 mL of 0.010 M acetic acid (pKa 4.76) with 0.010 MKOH. Calculate the pH of the solution after 490 mL of the titrant have been added. Calculate the pH of the solution after 500 mL of the titrant have ...

*February 3, 2017 by Crystal*

**Chemistry...Help?**

I've been trying to understand these two questions and I've re-read my textbook a dozen times but I still get confused. 27, A: Which is a stronger acid - sulfuric or carbonic acid? (Answer: Sulfuric acid.) 27, B: Imagine you have two glasses. One contains a solution of ...

*May 12, 2009 by Rachel*

**chemistry**

a 0.2000 grams sample of aluminum metal is added to a solution containing 1.0000grams of an unknown compound made of platinum and chloride ion. the reaction results in the formation of aluminum chloride and platinum metal. when the reaction is complete, unreacted aluminum ...

*March 3, 2014 by Anonymous*

**Stats Class HELP!**

Twenty-five blood samples were selected by taking every seventh blood sample from racks holding 187 blood samples from the morning draw at a medical center. The white blood count (WBC) was measured using a Coulter Counter Model S. The mean WBC was 8.636 with a standard ...

*April 18, 2014 by Katie*

**Organic Chemistry**

A half-life of a H2O2 solution at a certain condition is 4 weeks. You have a 100 mL of 1.00M H2O2 solution. How many moles of H2O2 will be left in the solution after the following weeks? 04 weeks after: moles 08 weeks after: moles 16 weeks after: moles 20 weeks after: moles

*July 1, 2012 by Ashley*

**chemistry**

you wish to combine two samples, one sample contains is solid water at 0 degree celsius.The other sample contains liquid water at 100 degree celsius,you want to combine both raise the temperature to 100 but boil off only 50 ml to gas phase keep the rest as liquid.How much ...

*May 30, 2014 by treasa*

**Math**

I'm really stuck on these STATS questions.Can someone please help! 1. The probability of a car in a population having faulty brakes is .05. If we take a sample of 150 cars, find the standard deviation of the sampling distribution. 2. The strength of ten I-beams produced in a ...

*June 20, 2013 by mysterychicken*

**MTH233/statistics UOP**

. Hypothesis Testing o Please complete the following 5-step hypothesis testing procedure in your Learning Teams: A simple random sample of forty 20-oz bottles of Coke® from a normal distribution is obtained and each bottle is measured for number of ounces of Coke® in the ...

*August 1, 2010 by sue*

**organic chemistry laboratory**

hi, im not sure if all my answers are correct especially number 5. could any one check and tell me? please and thank you. 1. Why is it important to have clean test tubes before running a test? Before which tests should acetone not be used to clean the test tubes? Due to ...

*November 2, 2014 by Niah*

**organic chemistry laboratory**

hi, im not sure if all my answers are correct especially number 5. could any one check and tell me? please and thank you. 1. Why is it important to have clean test tubes before running a test? Before which tests should acetone not be used to clean the test tubes? Due to ...

*November 4, 2014 by Niah*

**chemistry**

Polymers are high molecular weight compounds with a repeating structural unit. Polystyrene has the formula (CH CHZ) , where Z is C H and n is an integer. where n is 576 A solution of polystyrene in a solvent is prepared. Would you select H O, ethanol (CH CH OH), or toluene (C ...

*July 21, 2008 by alexis*

**chem**

A quantity of 16.13 mL of a KOH solution is needed to neutralize 0.4883 g of KHP. What is the concentration (in molarity) of the KOH solution? I don't even know where to begin with the first one. Calculate the amount of heat liberated (in kJ) from 375 g of mercury when it ...

*February 26, 2009 by ash*

**Molarity/molality**

A 3.29 m solution of the solute H2O dissolved in the solvent acetone is available. Calculate the mass ( kg ) of the solution that must be taken to obtain 26.70 mol of H2O. m= molality I have no idea how to approach this problem, I'm not interesting in getting the answer, I ...

*May 7, 2010 by ChEm*

**maths**

x^2-7x = 0 substitue x=7 into the equatiopn and explain why this shows that x=7 is the solution. ok so i do this: if x=7 then the equation becomes 7^2-49=0 7^2=49 49-49=0 so x=7 is correct (is that explanation enough?) now i have to write out a complete solution to the orginal...

*March 1, 2011 by Marian*

**Chemistry**

Air in the vicinity of a local power station contains 8.8x10^-4 gm^-3 SO2. What volume of 0.001moldm^-3 Iodine solution would be required to react with a solution obtained from 200dm^3 of contaminated air? The equation given is SO2 + I2 + 2H2O ==> H2SO4 + 2HI Thanks! :)

*January 26, 2013 by Matt*

**Chemistry**

A protein subunit from an enzyme is part of a research study and needs to be characterized. A total of 0.135g of this subunit was dissolved in enough water to produce 2.00 mL of solution. At 28 ∘C the osmotic pressure produced by the solution was 0.138 atm. What is the ...

*June 27, 2014 by Al*

**chemistry**

When magnesium metal and an aqueous solution of hydrochloric acid combine, they produce an aqueous solution of magnesium chloride and hydrogen gas. Using the equation, Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g), if 48.6 g of Mg and 150.0 g of HCl are allowed to react, ...

*July 8, 2014 by Kyra*

**chemistry step by step thank a lot**

Al2(s04)3 solution of a molal concentration is present in 1 litre solution of 2.684g/cc. How many moles of bas04 would be precipitated on adding bacl2 in excess? the answer 6M Who helps me step by step for me clearly I am thankful to all tutors

*July 11, 2014 by ken*

**college algebra need help asap**

Solve the system of equations using substitution. 2x−8y = 2 x+4y = 0 What is the solution? Select the correct choice below and fill in any answer boxes in your choice. A. m (Type an ordered pair.) B. There are infinitely many solutions. C. There is no solution.

*February 5, 2015 by mako*

**SCIENCE AGAIN**

My book does not have this question in it either. I tried various web sites. Maybe someone could help. Thank you "__________ is the solution to pollution" is an old axiom responsible for much of our problems in estuarine contamination. I am guessing that it possibly could be "...

*May 17, 2007 by Meg*

**Chemistry**

Hey guys! Trying to understand this problem before my Chem exam but I just can't get it down no matter how hard I try. Detailed solutions would be greatly appreciated because I'm so lost on this one. Thanks! What mass of ammonium chloride must be added to 5.00x10^2 mL of 0.10 ...

*March 24, 2016 by Joce*

**chemstry**

In a constant-pressure calorimeter, 50.0 mL of 0.340 M Ba(OH)2 was added to 50.0 mL of 0.680 M HCl. The reaction caused the temperature of the solution to rise from 23.69 °C to 28.32 °C. If the solution has the same density and specific heat as water, what is ÄH for this ...

*June 21, 2012 by cassie*

**Science**

In a constant-pressure calorimeter, 70.0 mL of 0.330 M Ba(OH)2 was added to 70.0 mL of 0.660 M HCl. The reaction caused the temperature of the solution to rise from 21.27 °C to 25.77 °C. If the solution has the same density and specific heat as water, what is ÄH for this ...

*October 10, 2012 by Marika*

**Chemistry**

In a constant-pressure calorimeter, 60.0 mL of 0.320 M Ba(OH)2 was added to 60.0 mL of 0.640 M HCl. The reaction caused the temperature of the solution to rise from 23.24 °C to 27.60 °C. If the solution has the same density and specific heat as water, what is ÄH for this ...

*February 26, 2013 by Blaire*

**Math**

Which term best describes the solution of the situation represented by the system of inequalities? (Assume that x >= 0 and y >= 0.) 3x + 4y <= 8 2x + 4y <= 6 Answer choices given are: a. alternate optimal solutions b. one optimal solution c. unbounded d. infeasible...

*November 14, 2014 by Sam*

**chemistry**

In a constant-pressure calorimeter, 65.0 mL of 0.330 M Ba(OH)2 was added to 65.0 mL of 0.660 M HCl. The reaction caused the temperature of the solution to rise from 21.91 °C to 26.41 °C. If the solution has the same density and specific heat as water, what is ÄH for this ...

*February 20, 2015 by rock*

**statistic**

suppose we wish to construct a confidence interval for a population proportion p. if we sample without replacement from a relatively small population of size N, the margin or error E is modified to include the finite population correction factor as follows: E=Za/2 pq/n N-n/N-1...

*April 17, 2012 by carl*

**chemistry**

The particles of which sample of LiCl(s) have the same average kinetic energy as the particles in a 2.0 mole sample of NH3(g) at 25 degrees celcius? a) 1.0 mole @ 75 degrees celcius b) 12.0 mole @ 50 degrees celcius c) 3.0 mole @ 25 degrees celcius d) 4.0 mole @ 0 degrees celcius

*May 15, 2010 by Anonymous*

**Chemistry**

Can an acidic solution be made less acidic by adding an acidic solution?

*May 11, 2011 by Angel*

**science**

what is produced when copper sulphate solution is mixed with ammonia solution? Either copper(II) hydroxide or copper(II) ammine sulfate or both depending upon the strength and the amount of ammonia added. The first is Cu(OH)2, the second is Cu(NH3)4SO4

*January 18, 2007 by anon*

**chemistry**

A solution is prepared with an unknown compound with an empirical formula of C3H7NO. The solution is made by dissolving 30.0 mg of compound in 1.200 g of the organic solvent biphenyl. The freezing point was depressed by 1.37C. What are the molar mass and molecular formula of ...

*February 12, 2011 by Ellene*

**Chem 111**

A solution is prepared by mixing 499 mL of 0.19 M Tris·Base and 592 mL of 0.37 M Tris·Acid. What is the pH of this solution? [Ka(Tris·Acid) = 8.5 × 10-9] Round your answer to two places past the decimal. I can do basic pH questions but I am at a loss on this one. Please help.

*March 25, 2012 by Brittany*

**PH Calculation**

Consider a 0.42 M solution of NaCH3COO CH3COO–(aq) + H2O(l) -> CH3COOH(aq) + OH–(aq) Calculate the pH of the solution at equilibrium. Try the weak acid or weak base approximation (as appropriate) and check the validity of the approximation. If the approximation is not ...

*April 26, 2012 by RZeal*

**Chemistry**

How many grams of cesium chloride (CsCl) will be needed to make 750. mL of a 0.100 M CsCl aqueous solution? The formula mass of CsCl is 168.36 g/mol. Remember Molarity: M = (mol solute) / (L of solution) I need help solving this problem

*December 6, 2015 by Mark*

**chemistry.**

A student was asked to make some copper(II) sulfate-5-5 (CuSO4.5(H2O) BY reacting copper(II) oxide (CuO) with sulfuric acid. a) Calculate the molar mass of the copper (II) sulfate-5-water which is (64+32+64) + (10+80)=250 mol b)Calculate the amount (in mol) of copper (II) ...

*October 24, 2009 by Denmark*

**College Chemistry**

A buffer solution contains 0.120M acetic acid and 0.150M sodium acetate. a. How many moles of acetic acid and sodium acetate are present in 50.0 ml of solution? b. if we add 5.55 mL of 0.092M NaOH to the solution in part (a) how many moles of acetic acid , sodium acetate, and ...

*November 10, 2010 by Elizabeth*

**Chemistry**

a solution contains an unkown amount of dissolved magnesium, addition odf 0.0877 mol of Na2CO3 causes complete precipitation of all the magnesium. what is the mass of magnesium was dissovled in the solution? you must write a balanced equation for the raction in order to solve ...

*April 28, 2011 by Monika*

**chemistry**

A sample being given as a laboratory unknown is a mixture of calcium carbonate and magnesium carbonate. Both substances decompose to form calcium oxide and magnesium oxide, respectively, when heated at a high temperature for a prolonged period. An unknown sample weighing 5.424...

*October 6, 2012 by anonymousokm*

**trigonometry**

1) Find the exact value of the expression: tan−1(tan(−120651/47π))... How do you find Tan(-120651/47pi)? I don't know how to find exact values, if it's not a recognizable value. 2)Find a simplified expression for tan(sin−1(a/5))... Because tan = y/x and ...

*May 3, 2015 by Dan*

**statistics**

Terms and Definitions matching ___ Statistics ___ Discrete variable ___ Statistics ___ Continuous variable ___ Population ___ Qualitative data ___ Population parameters ___ Quantitative data ___ Sample ___ Mean ___ Bias ___ Mode ___ Representative sample ___ Median ___ ...

*December 14, 2010 by Anonymous*

**maths**

how do i solve this equation? there is another answer other than 0, but i am not sure how to get it. 5x^2 + 7x =0 factor the term: x(5x+7)=0 Either term can be zero. You found the x=0, what value of x makes 5x+7 zero? Factor it to this form: x (5x + 7) = 0 There will be a ...

*January 12, 2007 by minerva*

**Chemistry**

You have a 12 M solution of hydrochloric acid. How many milliliters of this solution will give 25.0 mL of 2.0 M hydrochloric acid when diluted? Very confusing, If I can get a step by step process on how to figure this out, that would be great.

*September 6, 2008 by George*

**Chemistry**

You have a 12 M solution of hydrochloric acid. How many milliliters of this solution will give 25.0 mL of 2.0 M hydrochloric acid when diluted? Very confusing, If I can get a step by step process on how to figure this out, that would be great.

*September 6, 2008 by George*

**Science**

The label on a fertilizer says "ammonium phosphate, muriate of potash, sulfate of potash, and manganese oxide." Is this a mixture, solution or a compound? I don't think it could be a solution, but I'm not sure if it'd be a mixture or a compound-Thank you.

*March 13, 2009 by Sarita*

**Algebra**

Use substitution to determine whether the ordered pair (–2, –3) is a solution of the equation x2 – y = 7. Show some work. Be sure to state your conclusion about whether the ordered pair is a solution or not.

*June 9, 2009 by Jen*

**Algebra**

Use substitution to determine whether the ordered pair (– 3, – 2) is a solution of the equation 5x + y2 = –11. Show some work. Be sure to state your conclusion about whether the ordered pair is a solution or not.

*October 29, 2010 by Math Loser :(*

**Chemistry**

A solution is made by dissolving 3.5 moles of sodium chloride (NaCl) in 155 grams of water. If the molal boiling point constant for water (Kb) is 0.51 °C/m, what would be the boiling point of this solution?

*January 14, 2011 by Christi*

**Chemistry**

What is the molality of a 0.065M solution of ethyl alcohol in water at 25 degrees Celcius? (Assume the density of the solution at such low conentration is equal to that of water at 25 degrees Celcius, 0.997 g./mL)

*March 1, 2011 by Shai*

**Chemistry**

Can anyone tell me if I am right on these? Calculate the amount of solute needed to make each of the solutions 225g of 10% (m/m) K2CO3 solution Answer: 22.5g K2CO3 0.50kg of 18% (m/m) KOH solution Answer: 90g KOH

*May 19, 2011 by Julie*

**Chemistry**

How many milliliters of 0.277 M AgNO3 solution are needed to react completely with 47.1 mL of 0.278 M NaCl solution? How many grams of AgCl will be formed? The reaction is NaCl(aq) + AgNO3(aq) → AgCl(s) + NaNO3(aq)

*November 1, 2011 by Lynn*

**Chemistry**

You need to prepare 100.0 mL of a pH=4.00 buffer solution using 0.100 M benzoic acid (pKa = 4.20) and 0.240 M sodium benzoate. How much of each solution should be mixed to prepare this buffer?

*March 29, 2012 by Jematormal91*

**Bio Lab**

A scientist receives a vial containing protein at a concentration of 35mg ml -1 and is asked to add 0.25ml of it to 6.75mls of Biuret solution. What is the concentration of protein in the Biuret solution in mkg/ml?

*June 16, 2012 by Mandy*

**Chemistry**

Suppose you have to prepare 1.00 L of the solution ( KH2PO4 and Na2HPO4 pH=7.31) and that this solution must be isotonic with blood (have the same osmotic pressure as blood). What mass of KH2PO4 would you use?

*March 16, 2013 by Pepz*

**Chemistry**

You need to prepare 100.0 mL of a pH=4.00 buffer solution using 0.100 M benzoic acid (pKa = 4.20) and 0.180 M sodium benzoate How much of each solution should be mixed to prepare this buffer?

*August 13, 2013 by Adam*

**cheMYSTERY**

A 20.00 mL of 0.200mol/L magnesium chloride solution is added to a 95.00 mL of 0.800 silver (I) nitrate solution,Determine the concetration of the silver ions at the end of the reaction and the magnesium ions. and a precipitate is formed.

*April 22, 2014 by sandeep singh*

**Chemistry**

A 1N solution of NaOH is diluted 4/20 then rediluted 1:50. What is the final normality? How many grams of NaOH are present in 100ml of the final solution? I sort of understand the basic concept, but I don't really know how to do normality problems.

*May 20, 2014 by Jennie*

**chemistry**

A solution was prepared using 1,00 liter of water, 59 g glucose, and 2,3 g NaCl. One liter of water weighs 1000 grams. The solution needs to be labeled in terms of % glucose and % sucrose.

*September 19, 2014 by Sergejs*

**chemistry**

What would be the molarity of solution obtained by mixing equal volumes of 30% by mass H2SO4 (d=1.218 g/mL) and 70% by mass H2SO4 (d=1.610 g/mL). If the resulting solution has density 1.425 g/mL, calculate its molarity

*April 17, 2015 by jaimi*

**Chemistry**

you have 5% formic acid solution and a 5% acetic acid solution. You titrate 5mL each with .1868M NaOH. A. Which will need more NaOH to reach the end point? B. How much more?

*November 24, 2015 by jack*

**Algebra**

Meryl needs to add enough water to 11 gallons of an 18% detergent solution to make a 12% detergent solution. Which equation can she use to find g, the number of gallons of water she should be added

*December 14, 2015 by Que*

**Chemistry**

100g of water is added into 10.6M NaOH solution. The diluted NaOH then neutralized completely with H2SO4 . density of NaOH is 1.08g/ml . calculate the mole fraction of NaOH in diluted solution .

*June 28, 2016 by Amy*

**Chemistry**

100g of water is added into 10.6M NaOH solution. The diluted NaOH then neutralized completely with H2SO4 . density of NaOH is 1.08g/ml . calculate the mole fraction of NaOH in diluted solution .

*June 28, 2016 by Amy*

**Chemistry**

A is a solution of tetraoxosulphate(iv)acid.B contains 3.95g of sodium trioxocarbonate(iv) in 750cm3 of solution.if 22.70cm3 of the tetraoxosulphate(iv)acid neutralized 25.0cm3 of sodiumtrioxocarbonate(iv).calculate the concentration of i) B in moldm-3 ii) A in moldm-3

*December 8, 2016 by Yvonne*

**Math**

The smallest real number in the solution set of 2x > 6 is 4. A) True B) False - The smallest real number in the solution set of 2x > 6 is 3. C) False - The smallest real number in the solution set of 2x > 6 is a number greater than 3. For example, 3.01 is a real ...

*October 4, 2011 by Michelle*

**Math**

The smallest real number in the solution set of 2x > 6 is 4. A) True B) False - The smallest real number in the solution set of 2x > 6 is 3. C) False - The smallest real number in the solution set of 2x > 6 is a number greater than 3. For example, 3.01 is a real ...

*October 4, 2011 by Mary*

**chemistry please**

molarity of a solution containing 5mL of a 3.512 x 10^-5M solution (made from .128g of benzophenone and 50mL of ethanol) and then filled to the 50mL line of ethanol would this be (3.512 x 10^-5)(-.04) ?

*February 1, 2009 by john*

**Science**

I need to find out if sucrose, sucrose solution, sodium chloride, sodium chloride solution, water, vinegar, and aluminum are electrolytes and what type of bond they are but I don't know where to look.

*December 20, 2009 by Anonymous*

**Chemistry**

4.00 grams of NaOH have been added to 2.0 liters of water. The molarity of this solution is ____M. the concentration of this solution is ______ grams of NaOH per liter of water

*August 6, 2010 by Maria*

**Chemistry**

Calculate the amount of water (in grams) that must be added to (a)5.00 g of urea (NH2)2CO in the preparation of a 16.2 percent by mass solution, and (b)26.2g of MgCl2 in the preparation of a 1.5 percent by mass solution.

*September 19, 2010 by Diana*

**APC Chemistry**

Suppose you have a solution containing both an iron (II) salt and an iron (III) salt. How would you proceed to identify both Fe2+ and Fe3+ in this solution?

*September 29, 2010 by Anonymous*

**chem**

a solution of A (molar mass 100g/mol) and B (molar mass 1.10 x 10^2 g/mol) is prepared by mixing equal masses of the two. Find the mole fractions of each component in solution

*January 27, 2011 by Angela*

**Chemistry**

A quantity of 100 mL of .5M of HCl (aq) is mixed with 100 mL of .5M of NaOH (aq) in a constant pressure calorimeter. The initial temperature of the solutions is 22.30 C and the final temperature of the mixed solution is 25.00 C. What is "q" for solution and "q" for reaction?

*April 8, 2012 by Dante*

**chemistry**

A chemist want to make a 10% Chlorine solution from 30% Chlorine solution and pure water. How much of the two should the chemist mix together to make 20mL. Please help with calculations. Thank you

*August 31, 2012 by kate*

**Chemistry**

Assuming that the [Potato extract] is .001 M and I am going to make a 10 ml solution and each drop is 1/20th of a mL, how do I calculate the [Potato extract] in each reaction solution, using 20 drops, 15, 10, and 5 drops for each one?

*February 6, 2013 by Patricia*

**Chemistry**

A solution is made by mixing 37.0 mL of ethanol, C2H6O, and 63.0 mL of water.? Assuming ideal behavior, what is the vapor pressure of the solution at 20 °C? ethanol: 0.789 g/mL 43.9 torr water : 0.998 g/mL 17.5 torr

*March 2, 2013 by Dee*

**chemistry**

for an aqueous solution having Calcl2 (2molar) and Mgcl2 (5molal) and specified gravity of solution is 1.145 calculate molality of chloride ion and molality if chloride ion.

*May 10, 2013 by riya*

**Quatitative Analysis**

What is the correct charge balance equation for an aqueous solution of MnCl2 that ionizes to Mn2 , Cl–, MnCl , and MnOH ? What is the correct mass balance equation for the same solution?

*September 17, 2013 by Whitney*

**chemistry**

Knowing the concentration of a solution allows us to find all of the following except A. the mass of a solute. B. the mass of the solvent. C. the volume of the solvent. D. the concentration of a solution when conditions change.

*March 19, 2014 by Natalie*

**math**

A hallway measuring 90 feet x 7 feet requires 1/2 a fluid ounce of cleaning solution per square foot. How much cleaning solution is required to clean the hallway

*June 11, 2014 by Anonymous*

**Math**

Use the quadratic formula to solve the equation for x in terms of y and y in terms of x. (Enter your answers as a comma-separated list. If there is no solution, enter NO SOLUTION.) 2x^2 + 7xy + 1 − y^2 = 0 (a) x in terms of y x = (b) y in terms of x y =

*September 14, 2014 by Liam*

**chemistry**

A buffer solution is made by dissolving 0.45 moles of a weak acid (HA) and 0.23 moles of KOH into 720 mL of solution. What is the pH of this buffer? Ka = 6.2 × 10−6 for HA. Answer in units of pH. i need the answer

*January 31, 2015 by Anonymous*

**Chemistry**

20.00mL of 0.55M CH3COOH solution is mixed with 9.95mL of 1.0M NaHCO3 solution. The reaction occurring is CH3COOH + NaHCO3 --> CH3CHOO + Na + H2O +CO2. Which is the limiting reagent in this reaction?

*April 30, 2015 by Kate*

**Algebra 2**

Is the solution to this rational expression extraneous? The problem: (2x-3)/7 -(7x)/14 My answer: x = -9/4 My teacher wants to know if the solution is extraneous and I know I have to plug my answer back into the expression to check but I still don't understand.

*October 7, 2015 by Wade*

**Chemistry**

determine the vapor pressure lowering at 27 C of a solution of 750g of sucrose, dissolved in 180g of water. The vapor pressure of pure water at 27 C is 26.7 torr. Assume the solution is ideal

*October 11, 2015 by Anonymous*

**Chemistry**

you need to prepare 100 ml of ph=3.50 buffer solution using 0.100 M formic acid and 0.200 M sodium formate. how much of each solution shoudl be mixed to prepare this buffer?

*December 14, 2015 by Navi*

**math**

The equation for the pH of a substance is pH = –log[H+], where H+ is the concentration of hydrogen ions. A basic solution has a pH of 11.2. An acidic solution has a pH of 2.4. What is the approximate difference in the concentration of hydrogen ions between the two solutions?

*March 9, 2016 by Anonymous*

**Chemistry - Answer Check**

Find the molarity given 1.5 Liters of solution containing 62.5 g MgO. - 1.03 M Mgo There are 0.32 Liters of a 2.5 M HF solution. How many moles and grams of hydrofluoric acid are there? - 0.8 mol and 16 grams

*April 21, 2016 by Anonymous*

**chemistry**

I need a formula for: 0.5 grams of sodium chloride is dissolved to make 0.05 liters of solution. next 0.5 grams of sodium chloride is dissolved to make 0.05 ml of solution. next 670 grams of Pb (C2H3O2)4 are dissolved to make 3.5 ml of solution.

*May 19, 2011 by venita*

**Statistics**

Suppose the U.S. president wants an estimate of the proportion of the population who support his current policy toward revisions in the Social Security system. The president wants the estimate to be within 0.028 of the true proportion. Assume a 99 percent level of confidence. ...

*March 31, 2013 by Adam Dane*

**NEED HELP!**

A mixture contained CaCO3 and MgCo3. A sample of this mixture weighing 7.85g was reacted with excess HCl. The reactions are-- CaCO3 + 2HCl --> CaCl2 + H2O + CO2 MgCO3 + 2HCl --> MgCl2 + H2O + CO2 Is the sample reacted completely and produced 1.94L of CO2, at 25 degrees C...

*November 5, 2009 by Mary*

**chemistry help!**

A mixture contained CaCO3 and MgCo3. A sample of this mixture weighing 7.85g was reacted with excess HCl. The reactions are-- CaCO3 + 2HCl --> CaCl2 + H2O + CO2 MgCO3 + 2HCl --> MgCl2 + H2O + CO2 Is the sample reacted completely and produced 1.94L of CO2, at 25 degrees C...

*November 6, 2009 by Mary*

**science**

i need help with a packet that im struggling with my questions are write the total number of atoms present for the following questions: a. 4SO2 now i tried and got 8O'S and 1S b. 8O2 i tried and got 16 all together c. 3Al2(SO4)3 i tried and got 6Al, 3S, and 12O my next ...

*January 12, 2015 by maddy*

**Science- Chemistry**

A test tube containing a mixture of compounds X, Y, and a small amount of Z weighs 25.4886 g. The tube is emptied into a beaker and the empty tube is reweighed, giving a value of 10.2586 g. The mixture is separated into two components by dissolving in water, filtering off the ...

*October 13, 2012 by Sonia*

**CHEMISTRY PLEASE HELP**

Using the data collected for part c on your data sheet and assuming the density of the vinegar is 1.00g/mL, 1) calculate the molar concentration of acetic acid (CH3COOH) in the vinegar sample using the average volume of NaOH. 2) calculate the mass percent of acetic acid in the...

*October 24, 2011 by Josh*

**Chemistry**

How do you calculate alkalinity in chemistry? Ex: List the values for total alkalinity for Sample A and Sample B A 104 drops of titrant (5.25mL) 3 drops of C20 H14 O4 B 81 drops of titrant (4.25mL) 3 drops od C20 H14 O4

*August 15, 2016 by anon*

**science**

which is the correct balanced equation for a given titration process, (a) or (b)? a) 6H+ + 2MnO4- + 3H2O2 -> 4O2 + 2Mn2+ + 6H2O b) 6H+ + 2MnO4- + 5H2O2 -> 5O2 + 2Mn2+ + 8H2O Process: Make a solution in a 100mL volumetric flask using 1g of NaBO3*4H2O, 20mL of 1M H2SO4, ...

*March 30, 2011 by sarah*

**science**

you need to make a 3.5 Molar solution of Ca(OH)2, however, you only want to make 50ml of this Ca(OH)2 solution. How many grams of Ca(OH)2 will you need to weigh out and add to 50ml of water? Mass=VolumeinLiters*Molarity*Molmass

*December 12, 2006 by brittany*

**algebra**

Is (5,2) a solution of 4x-2y=-6 I said no, am I right? I am working on another problem where they want to know if this system of equations is perpendicular or parallel or neither, I said neither. Is this right? I am to solve by using elimination: 2x+3y=1, 4x+6y=2 I keep ...

*January 8, 2010 by Lara*