Wednesday

August 27, 2014

August 27, 2014

Number of results: 58,592

**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 *

**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**

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*

**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**

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*

**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*

**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*

**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*

**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*

**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*

**chm**

The molar solubility of PbBr2 at 250C is 1.0x10^-2. Calculate the Ksp.
*June 27, 2010 by ami*

**Chemistry**

Calculate the molar solubility of MgF2 in 0.08M MgCl2 at 25 degrees C.
*February 8, 2011 by Melissa*

**Chemistry**

#26 The Ksp of lead(II) carbonate, PbCO3, is 7.40 × 10-14. Calculate the solubility of this compound in g/L.
*October 24, 2012 by Mari Micci*

**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*

**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*

**chem**

The solubility product of silver sulfate is 1.6* 10^-5. What is the molar solubility of this compound? Ksp= [Ag]^2[So4^2-] 1.6*10^-5 = x^3 x= .0252 but the answer in my book is (16/4)^1/3 *10^-2 which equals to 0.158
*August 10, 2009 by Sara*

**chemistry**

predict the solubility of 2-propanol in dichloromethane and in water. Can someone explain how they came to their conclusion because I just dont understand how to determine solubility.
*March 8, 2012 by casey*

**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**

In a solution with carbon tetrachloride as the solvent, the compound VCl4 undergoes dimerization: 2VCl4 <-> V2Cl8 When 6.6834 g VCl4 is dissolved in 100.0 g of carbon tetrachloride, the freezing point is lowered by 5.97*C/ Calculate the value of the equilibrium constant ...
*December 10, 2013 by Anna*

**Chemistry**

When 4.65 g of a nonelectrolyte solute is dissolved in 475 mL of water at 27 °C, the resulting solution exerts an osmotic pressure of 931 torr. What is the molar concentration of the solution? How many moles of solute are in the solution? What is the molar mass of the solute? ...
*January 29, 2013 by Anon*

**Chemistry**

1. As a research chimst, you are intrested in studying the extent and type of interactions in aqueous salt solution. As part of this study, you weight three samples of NaCl and dissolve each in 1.000kg H2O. You then measure the freezing temp. of each solution and compare these...
*March 5, 2012 by Liz*

**finding boiling points of solutions **

What is the boiling point (in degrees Celsius ) of each of the solutions below? For water, Kb = 0.51 (Degrees C * kg)/mol The vapor pressure of water at 45.0C is 71.93 mm Hg. 1. A solution of 15.0g of urea, CH4N2O, in 164 g of water at 45.0 degrees C. For this one, I've gone ...
*September 9, 2010 by Sar*

**Science**

What happens when a compound iddolves in water? What does it mean if a compound has a solubility of 20g in 100g of water at 15 degree Celcius? Why are acids present in food are sage to eat? Explain what would happen if you mixed vingegar with a solution of ammonia. What type ...
*January 28, 2008 by Wenny*

**7th grade math Ms. Sue please**

1. 2(x – 3) = 2x (1 point) one solution no solutions infinitely many solutions 2. 3(y – 3) = 2y – 9 + y (1 point) one solution no solutions infinitely many solutions 3. 10x – 2 – 6x = 3x – 2 + x (1 point) one solution no solutions infinitely many solutions 4. 4(x + 3) + 2x = x...
*December 14, 2012 by Delilah*

**Chemistry**

Magnesium nitride can be produced by passing nitrogen gas over magnesium metal. 3Mg+N2 --> Mg3N2 IF 28.8g of Mg are mixed with 21g of N2 and allowed to react, which is the limiting reagent?
*July 24, 2008 by Amber*

**Chemistry**

The burning of the magnesium becomes uncontrolled (it burn brightly. Oops! How will this procedural error affect the reported mole ratio of magnesium to oxygen in the analysis? Explain.
*June 13, 2010 by Alex*

**Chemistry**

Need Help with these two problems 1.One piece of copper jewelry at 111Â°C has exactly twice the mass of another piece, which is at 36.0Â°C. Both pieces are placed inside a calorimeter whose heat capacity is negligible. What is the final temperature inside the calorimeter (c of...
*October 12, 2008 by Jamie*

**Algebra**

I need help on these kinds of radical problems. Once I get the examples solved, I think I can do others. 1. What is the solution to the square root of -9? No solution, yes or no? 2. The square root of: 6x/3x? The answer is 2? 3. The square root of -0.01? No solution? Is there...
*September 8, 2012 by Taurus*

**To DrBob222**

Can you please explain thoroughly to me about all this. Why do we criss cross the formulas of compounds? How do we find out which combining capacity to use if there are more than one? Is there a special formula we use to find out or something? I really do not understand. After...
*April 22, 2010 by Sara*

**chemistry**

A 50.00ml sample of 0.200M hydroflouric acid (HF) is titrated with 0.200M NaOH. The Pka of HF is 3.452. a) calculate the pH of the HF solution before titration b) calculate the pH after the addition of 20.00ml of NaOH
*November 6, 2010 by michelle*

**Chemistry **

This is a three part problem I need help in figuring out pleaseI n each of the questions below you are going to determine a different type of balanced equation for the same reaction. Make sure your equations have the lowest whole number coefficients possible. Indicate the ...
*October 10, 2012 by Melinda*

**Chemistry **

This is a three part problem I need help in figuring out pleaseI n each of the questions below you are going to determine a different type of balanced equation for the same reaction. Make sure your equations have the lowest whole number coefficients possible. Indicate the ...
*October 10, 2012 by Melinda*

**Physics**

How much heat must be removed when 25 grams of steam at 100°C Is condensed to form liquid water at 100°C?
*March 6, 2013 by tasha*

**Differential Equations**

Consider the differential equation: dy/dt=y/t^2 a) Show that the constant function y1(t)=0 is a solution. b)Show that there are infinitely many other functions that satisfy the differential equation, that agree with this solution when t<=0, but that are nonzero when t>0...
*January 31, 2013 by Erica*

**Differential Equations**

Consider the differential equation: dy/dt=y/t^2 a) Show that the constant function y1(t)=0 is a solution. b)Show that there are infinitely many other functions that satisfy the differential equation, that agree with this solution when t<=0, but that are nonzero when t>0...
*January 31, 2013 by Erica*

**Algebra 1 (Reiny or Kuai)**

1. Which x-values should I choose to graph these equations (y = x; y = -x + 6) so that they intersect? 2. The school band sells carnations on Valentine's Day for $2 each. They buy the carnations from a florist for $0.50 each, plus a $16 delivery charge. a. Write a system of ...
*December 9, 2013 by Please, help me!*

**chemistry**

The unit cell of palladiu m is a cube that is 389. 03 pm on a side. There are 4 Pd ato ms in the unit cell. Calculate the density of palladium in grams per cubic centimeter.
*May 17, 2011 by James*

**7th grade**

A solution can contain more than one aqueous solution. Name several of the aqueous solutions dissolved in water to make a drink with cola.
*February 1, 2009 by danielle*

**Chemistry II**

A solution contains the following: NH3(aq) + H2O(l) <--> NH4+(aq) + OH-(aq) Adding NH4Cl to this solution shifts the equilibrium of the given reaction to the left. What kind of reaction is this?
*October 28, 2009 by Mandy*

**Advanced Functions**

Consider the trig equation: 4sinxcos2x + 4cosxsin2x - 1 = 0 in the Interval [0, 2 pi] Either show that there is no solution to the equation in this domain, or determine the smallest possible solution.
*November 16, 2009 by Anonymous*

**chemistry-science**

A 500 ml buffer solution contains .2M Acetic acid and .3M sodium acetate. Find the pH of the buffer solution after adding 20 ml of 1M NaOH, what is the pH? (pka = 4.74)
*April 30, 2010 by jess*

**Chemistry**

A solution is made by dissolving 10.9 g of calcium chloride, CaCl2,in enough water to make exactly 500 mL of solution. What is the concentration (molarity) of CaCl2 in mol/L?
*July 24, 2010 by Shelia*

**College 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 7, only solution!
*August 12, 2010 by Alejandro*

**math please help**

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 10, only solution!
*August 29, 2010 by Katelynn Renee*

**chemistry**

a 340.4 ml sample of solution contains 27.4 g of cacl2. calcuate the molar concentration of calcium ion in this solution. this is what i did 27.4(110.98) =.247mol .247mol/34.4L=.726Mcacl2 is this correct?
*October 3, 2010 by amber*

**Chemistry**

What is the concentration of HCl when 25.0 mL of HCl completely reacts with 10.0 mL of 0.1M solution of NH4OH (subscript 4)? Solution steps would be helpful so I can solve other similar problems.
*November 22, 2010 by Cody*

**chemistry**

Neutralization Reaction Molarity Calculations: For example: What is the molarity of a Ca(OH)2 solution if .032 L of the solution is exactly neutralized by .015 of a 0.56 M HCl? How do I solve- I am unsure where to begin.
*April 25, 2011 by Hannah*

**chemistry**

Use the following balanced equation. 3Sr(OH)2 + 2H3PO4 --> 6H20 + Sr3(PO4)2 20 mL of H3PO4 is required to react with 40 mL of a 0.15 M Sr(OH)2 solution. What is the molarity of the H3PO4 solution?
*June 20, 2011 by Brea*

**Chemistry**

Assuming the sample is pure sodium sulfate, how many mL of 5% BaCl2.2H20 solution would be required to precipitate the sulfate. Density of barium shloride solution of 1.00 g/mL.
*October 8, 2011 by Mika*

**algebra,math**

Solve the equation. Check both solutions and only write the real solution. the square root of 6m minus 5 = m A. {1} B. {5} C. {1, 5} D. no real solution I think its B
*October 24, 2011 by tracy*

**biochemistry**

A solution was prepared by dissolving 8.0g of solid ammonium sulfate (MW= 132.14, specific volume= 0.565ml/g) in 35ml (i.e 35g) of water. What is the final volume of the solution?
*August 30, 2012 by KIm*

**Science**

A solution of silver nitrate is mixed with a solution of potassium sulphide.Write the molecular,total ionic,and net ionic equations illustrating the reaction.
*November 23, 2012 by Shane*

**Chemistry**

Consider a 0.71 M solution of each of the following salt dissolved in distilled water. Will the solution by basic, neutral, or acidic? KI= NH4NO2= (CH3CH2)3NHNO2= (CH3CH2)2NH2ClO4=
*December 11, 2012 by Chris*

**Chemisty Help Please!**

A solution is prepared by dissolving 25.0 g of glucose, C6H12O6, in 125 g of water at 25oC. (show work please) Determine the freezing point of the solution.
*January 14, 2014 by Igor*

**physical science**

A solution that contains a large amount of salt and a small amount of water is said to be a __________ solution. A. dilute B. unsaturated C. concentrated D. saturated
*June 7, 2014 by Unmei*

**math**

a drug is supplied as a 20 mg/ml solution in a 50 ml vial. you need to make 15 ml of a 10 mg/ml solution. how much concentrate and how much diluent are needed to obtain the desired final volume?
*July 9, 2014 by kate*

**analytical chemistry**

A solution containing both Fe 3+ and Al 3+ can be selectively analyzed for Fe 3+ by buffering to a pH of 2 and titrating with EDTA. Th e pH of the solution is then raised to 5 and an excess of EDTA added, resulting in the formation of the Al 3+ - EDTA complex. The excess EDTA ...
*May 4, 2013 by jody*

**Chem**

A precipitate is expected when an aqueous solution of porassium iodide is added to an aqueous solution of
*October 24, 2007 by Taylor*

**Chemistry**

Is it always apparent in a solution which component is the solute, for example, in a solution of liquid in a liquid?
*March 17, 2008 by Tyran*

**chemistry**

a 36.o% Aqueous solution of sucrose has a density of 1.16g/mL.What mass of sucrose is in 500mL of this solution?
*May 7, 2008 by katie*

**human resources**

a chemist has 400 mililiters (mL) of solution that is 21% acid. How many mililiers of acid are in the solution
*May 16, 2008 by carebear*

**chemistry**

How many gallons of distilled water must be mixed with 50 gallons of a 30% alchohol solution to get a 25% solution?
*September 6, 2008 by chelsea*

**Chemistry**

I am making a NaCl solution. What are the steps in calculating and weighing out NaCl for a 4 M solution.
*January 5, 2009 by Kyle*

**math**

how many liters of water must be added to 30 liters of a 20% alcohol solution to dilute it to a 15% solution?
*April 6, 2010 by Dawn*

**math**

how many liters of water must be added to 30 liters of a 20% alcohol solution to dilute it to a 15% solution?
*April 6, 2010 by Dawn*

**math**

how many liters of water must be added to 30 liters of a 20% alcohol solution to dilute it to a 15% solution?
*April 6, 2010 by Anonymous*

**chemistry**

If 24.7 of 0.250 M NaOH solution are needed to neutralize 19.8 mL of H2SO4 solution, what is the molarity of the H2SO4?
*May 28, 2010 by Cynthia*

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