Friday

September 19, 2014

September 19, 2014

Number of results: 59,236

**Math**

Simplify or solve as appropriate. Enter ns if there's no solution or all if the solution is all real numbers. 2 - 3(x + 5)) = 10 X = -7.6 7z + 6 - 2(z + 3) 5 * z 1/2x - 5 = 3/4x + 7 X = -48
*November 19, 2013 by Alan*

**Math**

I have a graph which is graphed by the equation f(x) = |x| - 4 and I'm asked to find the solution to the equation f(x) = 0. What would the solution be?
*February 5, 2014 by Anonymous*

**chemistry**

To what volume should you dilute 60mL of a 12.0M H2SO4 solution to obtain a 1.85M H2SO4 solution?
*April 8, 2014 by Amy*

**algebra**

what is the solution for 3x=27-15x and what is the solution for 7(2-m)=3m
*September 29, 2009 by Cristine*

**Algebra 1B**

ax^2+bx+c=0 solution: 9, only solution
*January 22, 2011 by Tabitha*

**physics**

What is a solution? What are the 2 parts of a solution
*January 20, 2012 by keria*

**science**

How many ml of a 2% solution will 20 ml of a 10% solution make?
*September 11, 2012 by jenny*

**Chem Help :(**

What is the pH of a solution in which [H3O^+] = 6.8 x 10^-5 M? What is the pH of a solution in which [OH^-] = 2.5 x 10^-9 M?
*February 17, 2014 by Tom *

**Organic Chemistry**

how many grams of ZnCl2 are needed to prepare 250 ml of an aqueous solution with an osmolarity equal to 0.300 osmol? I posted this question a few minutes ago, but forgot to add the last part of the sentence. Thanks!
*March 6, 2012 by Jules*

**Bio Chem**

Carbonate is commonly used to buffer household detergent solutions to a pH of 9.0. How many grams on NaHCO3 and how many grans of NA2CO3 are needed to prepare 0.75L of a 100mM solution? The 2nd pKa of carbonic acid is 10.33.
*September 4, 2014 by Cassandra *

**Chemistry**

Consider the titration of 100.0 mL of 0.260 M propanoic acid (Ka = 1.3 ✕ 10−5) with 0.130 M NaOH. Calculate the pH of the resulting solution after each of the following volumes of NaOH has been added. (Assume that all solutions are at 25°C.) (a) 0.0 mL...
*December 8, 2013 by Rina*

**Chemistry**

You have two beakers, one filled to the 100-mL mark with sugar (the sugar has a mass of 180.0 g) and the other filled to the 100-mL mark with water (the water has a mass of 100.0 g). You pour all the sugar and all the water together in a bigger beaker until the sugar is ...
*September 3, 2011 by Alexandria*

**CHEMISTRY TITRATION Q**

The titration of 25.00mL of Ba(OH)2 solution with an aqueous solution of 0.500 M HCl reaches an end point when 30.20 mL of the HCl solution is added. Determine the concentration of M of the Ba(OH)2 solution. Soo 25.00mL=0.025L 30.20mL= 0.0302L moles= MxL (0.500M)(0.0302L)=0....
*December 15, 2010 by LISA*

**Chemistry**

Caffeine C8H10N4O2, is a stimulant found in a tea and coffee. A sample of the substance was dissolved in 45.0g of choloroform CHCl3 to give a 0.0946m solution. How many grams of caffine were in the sample. m = molality
*February 6, 2008 by Lauren*

**DR.BOB HELP CHEMISTRY!**

How many milliliters of a 0.3 molar HCl solution are needed to react completely with 8 grams of zinc according to the following equation? ? HCl + ? Zn → ? ZnCl2 + ? H2 Answer in units of mL
*October 4, 2011 by Rara*

**Chemistry**

assuming complete dissociation of the solute, how many grams of KNO3 must be added to 275 mL of water to produce a solution that freezes at -14.5 C? The freezing point for pure water is 0.0 C and is equal to 1.86 C/m .
*January 27, 2012 by Colin*

**CHEMISTRY**

1)If 36 mL of KMnO4 solution are required to oxidize 25 mL of 0.02932 M NaC204 solution, what is the concentration of the solution? 2)A Certain brand of iron supplement contains FeSO4-7H2O with miscellaneous binders and fillers. Suppose 22.93 mL of the KMn04 solution used in ...
*November 1, 2010 by yipez*

**CHEMISTRY**

1)If 36 mL of KMnO4 solution are required to oxidize 25 mL of 0.02932 M NaC204 solution, what is the concentration of the solution? 2)A Certain brand of iron supplement contains FeSO4-7H2O with miscellaneous binders and fillers. Suppose 22.93 mL of the KMn04 solution used in ...
*November 1, 2010 by yipez*

**chemistry**

calculate the number of Mg2+ ions in each mL of 0.162M(molarity) magnesium bromide
*October 26, 2008 by ben*

**chemistry**

Mr. Arswan iss preparing a mixture for a science experiment. He measures 10.5 grams of wood shavings, 150 grams of iron filings, and 18.50 grams of salt. What is the total mass of Mr. Arswan`s mixture? A 30.5 grams B 179 grams C 150.5 grams D 17.9 grams
*October 6, 2013 by na*

**Chemistry**

Hg2+ + 2Cl- → HgCl Mercuric nitrate was standardized by titrating a solution containing 147.6 mg of NaCl(FM 58.44), which required 28.06 ml of Hg(No3)2 solution. Part a: Find the molarity of Hg(No3)2. I already calculated the molarity to be 0.04500 M Part b: When the ...
*October 16, 2011 by Asuna*

**Chemistry**

Ammonia has the formula NH3. Household ammonia is a dilute aqueous solution of NH3 . Aqueous ammonia is a base that can neutralize acids. If 18.4mL of 0.800 M HCl solution are needed to neutralize 5.00 mL of a household ammonia solution, what is the molar concentration of the ...
*February 11, 2009 by Chemistry*

**math **

How many cubic centimeters of a 25% antibiotic solution sould be added to 10 cubic centimeters of a 60% antibiotic solution in order to get a 30% antibiotic solution?
*October 18, 2009 by james *

**math **

How many cubic centimeters of a 25% antibiotic solution sould be added to 10 cubic centimeters of a 60% antibiotic solution in order to get a 30% antibiotic solution?
*October 18, 2009 by james *

**chemistry**

the density at 20 degrees celcius of a .258m solution of glucose in water is 1.0173 g/ml, and the molar mass of glucose is 180.2 g/mol. What is the MOLARITY of the solution?
*October 20, 2008 by Eric GReenblatt*

**Science**

If pale green FeCl2 solution is left in the open for some time, will some of it gradually oxidise to become brown FeCl3 solution?
*January 31, 2009 by candy*

**Algebra**

Write a quadratic equation in the variable x having the given numbers as solutions. Type the equation in standard form ax^2+bx +c = 0 The solution is 6 only solution.
*May 5, 2009 by aaron*

**chemistry**

A 1.10- sample contains only glucose and sucrose . When the sample is dissolved in water to a total solution volume of 25.0 , the osmotic pressure of the solution is 3.78 at 298 .
*January 24, 2010 by bf*

**Chemistry**

Determine the boiling point elevation of H2O in the following solution a 2.5 m solution of C6H12O6 in H2O All i need is the formulas because i dont know how to solve it Thank you :l
*March 7, 2010 by Veronica*

**algebra**

write a quadratic equation in the variable x having the given numbers as the solutions. type the equation in standard form ax^2+bx+c=0 solution 6, only solution
*July 11, 2010 by sam*

**math**

Solve the problem. If the answer is an amount of money, round to the nearest dollar. A chemical solution contains 3% salt. How much salt is in 4.5 ml of solution?
*August 17, 2010 by Sarah*

**chemistry**

The molarity of urea in a solution prepared by dissolving 16 g of urea (MW = 60.0 g/mol) in 39 g of H2O is __________ M. The density of the solution is 1.3 g/mL. i get 8.9 but the practice test says the answer its 6.3
*September 26, 2010 by BenY*

**chemistry**

The boiling point of an aqueous solution is elevated by 0.15 degrees celcius. the change in freezing point of the solution, delta T, is? a.) -6.32 b.) 0.15 c.) -0.15 d.) 0.54 e.) -0.54 I know the answer is d, i just don't understand how to get it! thanks!
*December 14, 2010 by Emily*

**Algebra**

Graph the two equations to solve the system. Write the ordered pair solution like this (1,2) with no spaces, or write no solution or infinitely many solutions. x + y = 6 and x - y = 4
*January 30, 2011 by joshua*

**Algebra**

Graph the two equations to solve the system. Write the ordered pair solution like this (1,2) with no spaces, or write no solution or infinitely many solutions. 1/2 x - 2y = 4 and 4y - x = -8
*January 30, 2011 by joshua*

**algebra**

write a quadratic equation in the variable x having given the numbers as sollutions type the equation in standard form ax^2+bx+c=0. solution 4 only solution
*February 8, 2011 by ella*

**chemistry **

predict whether or not a precipitate will form if you mix 75ml of a NaOH solution with pOH = 2.58 with 125ml of a 0.018M MgCl2 solution. Identify the precipitate, if any.
*April 9, 2011 by glenn *

**Chem/Solution Concentrationa**

How many gtams of potassium bromide(KBr), could be recovered by evaoportating 650.g of 15 percent KBr solution to dryness? Can you explain how to solve this?
*August 3, 2011 by Terr*

**algebra**

a scientist has a 25% acid solution.how many liters of each does the scientist need to make 15L of a solution that is 28%.write a system of equations and solve using any method.
*November 10, 2011 by geena*

**Chemistry**

How many mL of a solution of NaOH with pH equal to 1.395 x 101 do you need to mix with pure water to obtain 399 mL of a final solution with pH equal to 9.066 ?
*January 17, 2012 by Summer*

**chemistry**

What volume of solution would be needed to deliver the stated amount of solute? 237 milligrams of solute from a solution that is 32.0 ppm? answer in liters
*April 26, 2012 by toby*

**Chemistry**

Pb(NO3)2(aq) 2 x 10-3 M Na2SO4(aq) 2 x 10-3 M Pb(NO3)2(aq) + NaSO4(aq) → PbSO4(s)+ 2NaNO3(aq) a) What are the concentrations of each ion within this solution? b) If 1L of each solution is mixed; will a precipitate form? why?
*May 15, 2012 by Jake*

**chemistry**

20mL ethanol(density=o.789g/mol) is dissolved in sufficient water to produce a 200mL solution. the density of the solution is 0.982g/mL. what is the molarity?
*March 11, 2013 by mj*

**Aqueous Solution **

Write the positive and negative ions that result when the following compounds are dissolved in aqueous solution: Na2S (aq): (NH4)2CO3 (aq): K2SO4 (aq):
*March 17, 2013 by Annette W*

**aqueous solution**

Write the positive and negative ions that result when the following compounds are dissolved in aqueous solution: Na2S (aq): (NH4)2CO3 (aq): K2SO4 (aq):
*March 21, 2013 by Annette W *

**Alg 1**

Find the exact solution for each equation. Find the approximate solution to the nearest tenth. 5 sq rt 2/ sq rt 2 -1 = x / sq rt 2 Please explain in detail how to work this. I am really confused. Thanks
*April 3, 2013 by Jane*

**Chemistry**

A student mixes 450 mL of water and 116 mL of 7.90 x 10-5 M greenfood dye solution. What is the concentration of this new dilute solution of green food dye?
*April 29, 2013 by Tif*

**chemistry**

An aqueous solution of copper (II) sulfate is a thermodynamic system under study. What typer of system is this if the solution is contained in a beaker on a laboratory table?
*October 26, 2013 by Grace Peterson *

**chemistry**

A 25.0-ml sample of 1.00M KBr and a 75.0-ml are mixed. The solution is then heated to evaporate water until the total volume is 50.0 ml. What is the Molarity of the KBr in the final solution
*February 9, 2014 by Mary*

**College Chemistry**

A solution is saturated in both nitrogen gas and sodium iodide at 50 degrees C . When the solution is cooled to 25 degrees C what is most likely to occur?
*March 23, 2014 by Brandy*

**Chemistry**

What is the ionic strength, I, of a solution at 25C containing 0.002 mol/L of BaSO4 and 0.001 mol/L of BaCl2? What is the activity coefficient of Ba2+ in this solution?
*April 8, 2014 by Me*

**chemistry **

A sample of solid ammonium chloride, NH4Cl, is dissolved in water. The solution formed was found to be acidic. Can you please explain why the solution is acidic?
*July 14, 2014 by lilliso *

**chemistry**

The total acidity in water samples can be determined by neutralization with standard sodium hydroxide solution. What is the total concentration of hydrogen ion, H+, present in a water sample if 300. mL of the sample requires 7.5 mL of 2.8 10-3 M NaOH to be neutralized? im ...
*March 26, 2009 by lyne*

**NEED HELP WITH CALC**

Suppose strontium-90 decays at a rate of 2 percent per year. (a) Write the fraction P of strontium remaining, as function of t, measured in years. (Assume that at time t=0 there is 100 % remaining.) Answer: P(t) = (b) Estimate the half-life of strontium. Answer: Hint: Use your...
*June 27, 2014 by Anonymous*

**Physical Science**

To create a supernaturated solution, a student heats a beaker of water on a hot plate and adds sugar until no more sugar will dissolve. The student then strains the solution through a funnel using filter paper and allows the solution to cool. Name two safety procedures the ...
*January 12, 2011 by SHAZAM*

**chemistry**

Which solution would CaC2O4 be most soluble in? Na2C2O4 NaHC2O4 H2C2O4 NaCl HCl I due to common ions i think it would be one of the first three and i think it is Na2C2O4 because the other 2 have Hydrogen. Is it Na2C2O4? No, the common ions work just the other way; CaC2O4 will ...
*April 7, 2007 by jacob*

**chemistry**

Calculate the concentration, in percent by mass, of a refrigerant brine solution which is 4.03 M in NaCl with a density of 1.116 g mL-1.
*November 9, 2007 by keely*

**chemistry**

Calculate the Ka of nitrous acid if a 0.200 mol/L solution at equilibrium at SATP has a percent ionization of 5.8%
*April 5, 2008 by Laura*

**chemistry**

Calculate how much energy will be released when 11.11g of calcium chloride are dissolved in 100ml of solution
*May 2, 2009 by Mandy*

**chemistry**

Commercial bleach contains 5.25% (by mass) of NaClO in water. It has a density of 1.08 g/mL. Calculate the molarity of this solution.
*March 3, 2010 by Drew*

**Chemistry**

Calculate the freezing- and boiling-point changes for a solution containing 12.0 g of naphthalene (C10H8) in 50.0 g of benzene.
*May 2, 2010 by Mariah*

**chemistry**

calculate the percent composition or w/v% of 3x10 to the 2nd power mL solution containing 15g of glucose
*May 4, 2010 by Quentin*

**Chemistry**

What formula do I use to calculate the mass of KCl that is required to make 625 mL of a 0.200 M solution?
*July 25, 2010 by Norma*

**Chemistry**

Calculate the freezing point of each of the solution 75.0 of glucose,C6H12O6 , added to 9.30×10−2 of water.... Please help
*December 6, 2010 by Garrett*

**science**

You add 12.5 mL of 4.15 acetic acid to 25.0 mL of 1.00 M NaOH. Calculate the hydronium ion concentration and pH of the resulting solution.
*March 7, 2011 by Bill*

**chemistry**

calculate the volume of 3M HCl needed to change the pH of 50 mL of the undiluted buffer solution by one pH unit?
*March 16, 2011 by Anonymous*

**Genral chemistry **

if you dissolve 1.60g of Cu(No3)2 in 100mL of water, calculate the molarity of the resulting solution ?
*March 30, 2011 by Abdul*

**chemistry**

For a solution that is 0.280M HC3H5O2 (propionic acid, Ka= 1.3*10^-5) and 0.0894M HI , calculate the following: [H3O+] [OH-] [C3H5O2-] [I-]
*April 14, 2011 by Saunders*

**Chemistry**

5.85 g of sodium chloride(NaCl) is dissolved in 250 mL OF solution. Calculate mass percentage of the solute.
*October 28, 2011 by Dewa*

**Chemistry**

The osmotic pressure of a liquid at 320 K is 145 kPa. Calculate the freezing point of the solution.
*November 29, 2011 by David*

**chemistry**

Calculate the ionic strength of 100mM solution of Mg3(PO4)2 in 10 mM acetic buffer (CH3COONa)
*December 14, 2011 by Nan*

**Chemistry**

Calculate the [OH-] for a solution in which [H+] is 1000 times greater than [OH-]? and will the final result be acidic, basic, or neutral?
*February 25, 2012 by Colin*

**Chemistry**

Calculate the pH of a buffer solution obtained by dissolving 16.0 g of KH2PO4(s) and 27.0 g of Na2HPO4(s) in water and then diluting to 1.00 L. (pKa=7.21)
*March 29, 2012 by Jematormal91*

**chemistry**

Calculate the pH and percentage protonation of the solute in an aqueous solution of 0.39 M quinine if the pKa of its conjugate acid is 8.52.
*April 24, 2012 by bob*

**Chemistry**

Calculate the amount (volume) of 0.135 M HClO4 solution required to neutralize 57.00 mL of .089 M NaOH
*October 6, 2012 by Vicky*

**Chemistry **

Calculate the molality, molarity, and mole fraction of FeCl3 in a 39.2 mass % aqueous solution (d = 1.238 g/mL).
*February 16, 2013 by Stevi*

**Chemistry**

Calculate the pOH of an aqueous solution of 146.6 ml of 0.000625 M HBr(aq) after dilution to 850 ml.
*March 21, 2013 by Mary Ann *

**Chemistry**

Calculate the pOH of an aqueous solution of 146.6 ml of 0.000625 M HBr(aq) after dilution to 850 ml.
*March 21, 2013 by Mary Ann *

**Chemistry**

Calculate the pOH of an aqueous solution of 146.6 ml of 0.000625 M HBr(aq) after dilution to 850 ml.
*March 21, 2013 by Mary Ann *

**Math**

Calculate the morality of a solution made by mixing 250ml of 0.75M H2SO4 with 400ml of 2.5MH2SO4
*March 26, 2013 by Alica*

**chemistry**

Calculate the concentrations of all species present C6H5N2, C6H5NH3+ OH^-, and H3O^+}) in a 0.14 M solution of aniline.
*April 5, 2013 by kim*

**chemistry**

calculate the enthalpy of mixing for the solution of 10% platinum and 90% gold .express your answer in units of kg/mole
*May 7, 2013 by himani.*

**Chemistry**

A solution contains 80.0 g of sodium chloride and 400.0 g of water. Calculate the NaCl as a mass percentage
*June 2, 2013 by Monica*

**chemistry**

Calculate the molarity (M) of a solution of the strong acid H2SO4 if the hydrogen ion concentration is 0.000244 M.
*October 10, 2013 by HELP ASAP PLEASE*

**chemistry**

calculate the mass of Cuso4.5H2O required to prepare 500 cm3 of a 0.400 m/dm-3 solution
*June 8, 2014 by alice*

**science**

calculate the mass of Cuso4.5H2O required to prepare 500 cm3 of a 0.400 m/dm-3 solution
*June 8, 2014 by alice*

**chemistry, biology**

Calculate the pH of a solution obtained by adding 20 mL of .2M KOH to 480 mL to .02M isoelectric glycine
*July 6, 2014 by Laurel*

**chemistry**

calculate the molality, molarity, and mole fraction of NH3 in an 12.80 mass % aqueous solution (d=0.9651 g/ml)
*September 8, 2014 by maria*

**chemistry**

How many grams of magnesium metal will react completely with 5.2 liters of 4.0 M HCl? Show all of the work needed to solve this problem. Mg (s) + 2 HCl (aq) yields MgCl2 (aq) + H2 (g)
*May 21, 2014 by Tessa*

**algebra**

How do you know if a value is a solution for an inequality? How is this different from determining if a value is a solution to an equation? If you replace the equal sign of an equation with an inequality sign, is there ever a time when the same value will be a solution to both...
*May 21, 2008 by Anonymous*

**Algebra**

How do you know if a value is a solution for an inequality? How is this different from determining if a value is a solution to an equation? If you replace the equal sign of an equation with an inequality sign, is there ever a time when the same value will be a solution to both...
*May 26, 2008 by Anonymous*

**George School**

Ag2CrO4(s) + 2e- 2Ag(s) + CrO42-(aq) A chemist wishes to determine the concentration of CrO42- electrochemically. A cell is constructed consisting of a saturated calomel electrode (SCE; which has a reduction potential of 0.242 V relative to the SHE) and a silver wire coated ...
*May 20, 2008 by Daniel*

**physic**

The amount of heat released when 100 grams of steam at 100 degrees Celsius is converted into liquid water at 100 degrees Celsius is ____ J.
*March 26, 2011 by bode*

**physics**

The amount of heat released when 100 grams of steam at 100 degrees Celsius is converted into liquid water at 100 degrees Celsius is ____ J.
*July 22, 2012 by mikmi*

**Chemistry**

1)Buttermilk has 9 grams of protein and 12 grams of carbohydrate per cup (237ml). Estimate the concentration in mol/L of protein using the fact that the average protein is 300 amino acids long and the average amino acid has a mass of 110 amu. 2)Lactose (MW:342 amu) makes up ...
*October 10, 2013 by qwerty*

**Calculus**

I need to find the exact solutions on the interval [0,2pi) for: 2sin^2(x/2) - 3sin(x/2) + 1 = 0 I would start: (2sin(x/2)-1)(sin(x/2)-1) = 0 sin(x/2)=1/2 and sin(x/2)=1 what's next? Ok, what angle has a sin equal to say 1/2 sin (x/2)=1 arc sin (1) = x/2 PI/2=x/2 solve for x do...
*August 21, 2006 by Jen*

**chemistry**

Subject – equilibria Pure ethanoic acid (25.0cm3, CH3COOH), pure ethanol (35.0 cm3, C2H5OH) and pure water (20.0cm3, H2O) were mixed in a sealed flask at room temperature. The flask was placed in a heated water bath and maintained at 323K until equilibrium was established. ...
*May 7, 2012 by yaya*

**chemistry**

I have no clue, please help and explain! =) Find the pH of a 0.150 M solution of a weak monoprotic acid having Ka=1.2×10−5. Find the percent dissociation of this solution. Find the pH of a 0.150 M solution of a weak monoprotic acid having Ka=1.4×10−3. Find the ...
*December 6, 2010 by Lisa, Help needed!*

**chemistry**

1. a) 50ml of water at 46.9°C were mixed with 50ml of water at 25.1°C in a calorimeter also at 25.1°C. The final temperature was 30.1°C. Assuming that neither the density of water nor its specific heat capacity change with temperature, calculate the total heat capacity of the ...
*November 12, 2012 by Cicily*

**chemistry**

Calculate the solubility (in g/L) of silver carbonate in water at 25°C if the Ksp for Ag2CO3 is 8.4 x 10^-12
*April 17, 2010 by Bababa*

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