# 10% solution

22,140 results

**Chemistry**

An aqueous KNO3 solution is made using 73.4g of KNO3 diluted to a total solution volume of 1.86 L. Calculate the molarity of the solution. (Assume a density of 1.05 g/ml for the solution.)

**college algebra**

a chemist needs to prepare 28 ounces of a 8% hydrochloric acid solution. find the amount of 14% solution and the amount of 7% solution he should mix to get this solution.

**Chemistry**

You have a large amount of 8.00 M stock solution. You need 1.60 L of 3.00 M solution for an experiment. How would you prepare the desired solution without wasting any stock solution?

**Chemistry**

You have a large amount of 8.00 M stock solution. You need 1.60 L of 3.00 M solution for an experiment. How would you prepare the desired solution without wasting any stock solution?

**Buffer Solution**

You have 500.0 mL of a buffer solution containing 0.30 M acetic acid (CH3COOH) and 0.20 M sodium acetate (CH3COONa). What will the pH of this solution be after the addition of 93 mL of 1.00 M NaOH solution?

**Science**

You have a stock solution of 3.5M glucose. You need a working solution of 0.5M glucose in a volume of 400ml. Explain how you make the solution. Also what is the concentration of the dilution solution?

**chemistry**

X is a solution,of dibasic of H2X. G is a solution containing 1.00g of NaOH in 250cm3 of solution . 24.60cm3 of solution F required 25.00cm3 of solution G . From your result and information provided above. (I)concentration of G in mol/dm3 (ii) concentration of F in mol/dm3 (...

**Math**

A pharmacist is to prepare a 50 fluid ounce solution that contains 54% glucose. The pharmacy has a 30% solution and a 90% solution on hand. How many ounces of each solution should be mixed to prepare the desired perscription?

**chemistry**

the density of a certain aqueous solution is 1.17g/ml, and the solution is 3.57% by mass NaOH. how many mL of this solution would you need to use in order to prepare 100.0 mL of .150 M NaOH solution?

**CHEMISTRY**

1. How would you take 1L of an existing solution with a concentration of 1M and use it to make a new solution of 0.1 M? Be specific. 2. Would it be possible to easily create a 2 M solution from 100 mL of 1 M solution? Explain why or why not?

**Chemistry**

1. How would you take 1L of an existing solution with a concentration of 1M and use it to make a new solution of 0.1 M? Be specific. 2. Would it be possible to easily create a 2 M solution from 100 mL of 1 M solution? Explain why or why not?

**science**

A solution of aqueous ammonia contains 28.0% NH3 by mass. the solution has a density of 0.898g/mL. calculate the volume of this solution required to make 425mLof 0.320M NH3 solution.

**Chemistry **

A 150ml solution of 0.340M HCl is mixed with a solution of 340ml of 0.175M HNO3. The solution is then diluted to a final volume of 1.00L. How many moles of H+ are present in the final solution?

**Math**

A druggist mixes a 10% solution of iodine with a 15% solution of iodine. How much of each solution should be used in order to obtain 20 cubic centimeters of a 12% solution?

**Chem**

An aqueous KNO3 solution is made using 82.7 grams of KNO3, diluted to a total solution volume of 1.50 L. The density of this solution is 1.05 g/mL. What is the molality of this solution?

**chemistry**

You were given 25.00 ml of an acetic acid solution of unknown concentration. You find that it requires 29.60 ml of a 0.1050 M NaOH solution to exaclty neutralize this sample. A) What is the molarity of the acetic acid solution? B) what is the percentage of acetic acid in the ...

**chemistry**

Calculate the molar concentrations for each of the following solutions: A)1.5g NaCI in 100 ml solution B)1.5g K2Cr2O7 in 100 ml solution C)5.55g Na2SO4 in 125 ml solution D)20g MgBr2 in 250ml solution

**chemistry**

calculate the volume(ml) of a 0.215M KOH solution that will completely neutralize each of the following? a) 2.50ml of a 0.825M H2SO4 solution b) 18.5ml of a 0.560 M HNO3 solution c) 5.00mL of a 3.18 M H2SO4 solution

**chem**

You have a large amount of 7.50M stock solution. You need 1.80L of 3.00M solution for an experiment. How would you prepare the desired solution without wasting any stock solution?

**Chemistry**

A solution is prepared by dissolving 571.6 g of H 2SO4 in enough water to make 1000.0 mL of solution. The solution has a density of 1.3294 g/mL. (molar mass of H2SO4 = 98.08). What is the molar concentration of the solution?

**chemistry**

A 150.0-mL sample of Solution A is diluted to a total volume of 423 mL to form Solution B. If the concentration of Solution A was originally 20.0 mg/L, what is the concentration (in mg/L) of Solution B?

**Chemistry**

A solution has [OH-] = 3.5 × 10-6. Based on that, what must be true about this solution? A. It is an acidic solution. B. It is a strong base. C. It is a strong acid. D. It is a basic solution.

**chemistry**

AgNO3 was dissolved in water to make 10mL of solution. Then 3.0mL of that solution was used to make a new solution with a total volume of 1.000L. What was the concentration of the silver ion in the final solution?

**chemistry 1046**

A.Determine the pH of the solution. a solution that is 1.17% HCl by mass (Assume a density of 1.01 g/mL for the solution.) B. Amphetamine (C9H13N) is a weak base with a pKb of 4.2. Calculate the pH of a solution containing an amphetamine concentration of 279 mg/L.

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...

**Chemistry**

I can't figure out how to set up this problem...You have a large amount of 8.00 M stock solution. You need 1.80L of 3.00 M solution for an experiment. How would you prepare the desired solution without wasting any stock solution?

**chemisry**

An unknown amount of water is mixed with 350 mL of a 6 M solution of NaOH solution. A 75 mL sample of the resulting solution is titrated to neutrality with 52.5 mL of 6 M HCl. Calculate the concentration of the di- luted NaOH solution. Answer in units of M

**AP Chemistry**

An unknown amount of water is mixed with 350 mL of a 6 M solution of NaOH solution. A 75 mL sample of the resulting solution is titrated to neutrality with 52.5 mL of 6 M HCl. Calculate the concentration of the diluted NaOH solution. Answer in units of M

**CHEMISTRY**

n unknown amount of water is mixed with 350 mL of a 6 M solution of NaOH solution. A 75 mL sample of the resulting solution is titrated to neutrality with 52 . 5 mL of 6 M HCl. Calculate the concentration of the di- luted NaOH solution. Answer in units of M

**Algebra 1 check answers**

If you were solving a system of equations and you came to a statement like 1 = 3, what do you know about the solution to the system? The solution is (1, 3). The solution is x = 1 and y = 3. There is no solution. There are infinitely many solutions. I think the answer is D or B...

**Algebra**

100mL of a solution contains 30 mL of acid; this is called a 30% acid solution because part 30 ---- = ---- = 0.30. whole 100 How many milliliters of acid x would need to be added to the solution to turn it into a 50% solution ? (HInt: Adding acid increases both the volume of ...

**algebra**

A chemist has a solution that is 20% HIC and a solution that is 50% HCI. How much of each solution should be mixed to attain 300ml of a solution that is 30% HCI?

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...

**Chemistry**

A student makes a solution by dissolving 55.8 grams of potassium hydroxide in 875.0 grams of water. The resulting solution has a density of 1.07 grams per milliliter. 1. What is the volume of this solution? 2. Calculate the % concentration of this solution. 3. Calculate the ...

**chemisrty**

Q4) Suppose you prepare 950 mL of a solution by dissolving 100 grams of NaCl in 900 mL of water. Assuming the density of pure water to be 1 g/mL, answer the following questions with regards to this solution: a) What is the mass percent of water in this solution? b) What is ...

**chemistry help asap**

Please check these thanks. 1. In a titration, 33.21 mL 0.3020M rubidium hydroxide solution is required to exactly neutralize 20.00 mL hydrofluroic acid solution. What is the molarity of the hydrofluroic acid solution? Answer: 0.502HF 2. A 35.00 mL-sample of NaOH solution is ...

**algebra**

3x + 4 > 9, with x = 2 determine whether or not the solution provided is a solution to the inequality. If the value he or she provides is a solution, provide a value that is not a solution. If the value is not a solution, provide a value that is a solution.

**Chemistry**

A 0.60 L portion of a 1.2 M AgNO3 solution is mixed with a 0.3 L potion of a 1.2 M Na2CrO4 solution in an constant pressure calorimeter. Upon mixing, the solid Ag2CrO4 is formed and the heart released is 48.2 kJ. The specific heat of the solution is 4.18 J/C*g and the final ...

**Chemistry**

A sample of solid Ca(OH)2 is stirred in water at 30°C until the solution contains as much dissolved Ca(OH)2 as it can hold. A 100.-mL sample of this solution is withdrawn and titrated with 5.00 X 10^-2 M HBr. It requires 48.8 mL of the acid solution for neutralization. What ...

**algebra**

a chemist needs 10 liters of a 25% acid solution. the solution is to be mixed from three solutions whose acid concentrations are 10% 20% 50% how may liters of each solution should the chmist use to satisfy the following? a use as little as possible of the 50% solution b use as...

**chemistry**

Which solutions are acidic? (Assume all solutions are at 25°C. Kw = 1.0 x 10-14 at 25°C.) A. A solution with [H+] = 9.4 x 10-6 B. A solution with [H+] = 5.5 x 10-10 C. A solution with pH = 6.1 D. A solution with [OH-] = 6.4 x 10-7 E. A solution with [OH-] = 2.0 x 10-6

**Solving Rational Equations**

100mL of a solution contains 30 mL of acid; this is called a 30% acid solution because part 30 ---- = ---- = 0.30. whole 100 How many milliliters of acid x would need to be added to the solution to turn it into a 50% solution ? (HInt: Adding acid increases both the volume of ...

**math**

in the lab, tom has two solutions that contain alcohol and is mixing them with each other. he uses 300 millilters less of solution A than solution B. solution A is 10% alcohol and solution B is 13% alcohol. How many millilters of solution B does he use, if the resulting ...

**math / algebra**

n the lab, Bob has two solutions that contain alcohol and is mixing them with each other. He uses 400 milliliters less of Solution A than Solution B. Solution A is 20% alcohol and Solution B is 13% alcohol. How many milliliters of Solution B does he use, if the resulting ...

**Chemistry**

If a solution of sodium hydroxide is mixed from a 3M solution of sodium hydroxide, such that the volume of the original solution is 50ml and the volume of the final solution is 150ml, determine each of the following: a. The volume of water added to the solution b. The new ...

**Chemistry (Help)**

0.275gAgNO3 is dissolved in 500mL of solution. a. What is the molarity of this solution. b. If 10.0 mL of this solution are transferred to a flask and diluted to 500mL, what is the concentration of the resulting solution? c. If 10.0mL of the solution in (b) are transferred to ...

**Chemistry**

What is the molarity of a solution with 3.5mol of CaCl2 in 1.89L of solution What is the molarity of a solution with 16g of CH3OH in 487mL of solution

**Chemistry**

A 2% solution of Hydrochloric acid is required for a procedure. A 5% solution is availabe. How much of the 5% solution will be required to make 1 L of solution?

**chemistry**

A solution contains 4.46 g KCl in 178 mL of solution. The density of the KCl solution is 1.11 g/ml. What is the percent (m/m) for the potassium chloride solution?

**Math**

If a mixture of a 6% acid solution with an 11% solution is to be made, how much of each solution is needed to make 10 liters of an 8% acid solution?

**algebra**

In mixing a weed killing chemical a 40% solution of the chemical is mixed with an 85% solution to get 20 L of a 60% solution. How much of each solution is needed?

**college chemistry**

Suppose you have a 0.200 M solution of the nitrogen-containing weak base NX. Suppose you wish to titrate 25 mL of this 0.200 M NX solution with a 0.100 M solution of the strong acid HNO3. Given that the Kb value of NX is 6.50x10-5, complete each of the following: a) What ...

**chem**

A solution contains 4.60 g KCl in 179 mL of solution. The density of the KCl solution is 1.11 g/mL What is the percent (m/m) for the potassium chloride solution? What is the molarity, M, for the potassium chloride solution? need help pls

**chem**

. (a) A solution was prepared by dissolving 1.4295 g of magnesium chloride (MgCl2) into water and made up to 25.0 mL, calculate the molar concentration of the solution. (3 marks) (b) A 250.0 mL of 0.50 M solution of sodium phosphate (Na3PO4) solution was prepared by diluting 1...

**math**

A lab needs a 20 liters of a 15% acid solution. The lab only has a 10% acid solution and a 30% acid solution. How much of the 10% acid solution will they need to mix with the 30% solution to obtain 20 liters of a 15% solution?

**Math**

Alyssa is a chemist with Gemco Pharmaceutical Company. She needs to prepare 12 ounces of 9% hydrochloric acid solution. The only solution she currently has available are 4% and 12% hydrocholoric acid. How much should she use of each solution to obtain the needed solution.

**Chemistry**

(a) Calculate the molarity of a solution that contains 0.175 mol ZnCl2 in exactly 150 mL of solution. (b) How many moles of HCl are present in 35.0 mL of a 4.50 M solution of nitric acid? (c) How many milliliters of 6.00 MNaOH solution are needed to provide 0.325 mol of NaOH?

**Math help please thank you**

Chris needs to make 500 L of a 35% acidic solution. He has only two of the acidic solutions available, a 25% solution and a 50% solution. How many litres of each acidic solution should he mix?

**Chemistry**

Standardization of iodine solution was prepared using 10.0 mL of a standard, 1.00 mg/mL, ascorbic acid solution. Titration with the iodine solution required 35.80 mL to reach the end point. What is the molarity of the iodine solution?

**Chemistry**

a solution is prepared using .015 L of 1.0 M HCl and .020 L of .50 M HNO3. the final volume of the solution is 1.25 L. Answer th following questions. a)what are the [H3O+] and [OH-] in the final solution? b)What is the pH of the final solution?

**chemistry**

An aqueous solution of phosphoric acid, H3PO4, contains 285 g H3PO4 in 400 mL solution, and has a density of 1.35 g/mL. Calculate a. the weight % H3PO4 in this solution. b. the concentration in mol/L of this solution

**Chemistry Honors**

Arthur is performing a lab which requires a 0.2 M solution of calcium hydroxide. However, the only calcium hydroxide solution available has a concentration of 0.5 M. How can Arthur dilute the 0.5 M solution to make 10 mL of a 0.2 M solution? A.He needs to add 2.5 mL of the 0.5...

**Math help!**

1.(g + 4) - 3g = 1 + g 1 4 No solution Identity 2. 5y + 2 = 1/2(10y + 4) 5 10 No solution Identity 3. 0.5b + 4 = 2(b + 2) 0 0.5 No solution Identity 4. -3x + 5 = -3x + 10 5/6 -5/6 No solution Identity My answers: 1. 1 2. Identity 3. 0 ??? Not sure 4. No solution I really need ...

**Algebra**

A chemist needs to mix a solution containing 30% insecticide with a solution containg 50% insecticide to make 200L of a solution that 42% insecticide. How much of each solution should she use? dealing with- graphing, subst., and elimin.

**chemistry**

When 25 mL of C2H5OH (density 0.80 g.cm-3) is dissolved in water to prepare a 250 mL solution, the density of the solution was found to be 0.950 g.cm-3. Calculate a. Molarity of pure ethanol; b. Molarity of ethanol in the final solution; c. Volume of the final solution which ...

**Chemistry**

I was just wanting to make sure I did these right. How many grams of solute are in each of the following solutions? a.) 2.5 L of 3.0 M Al(NO3)3 solution. for this one I get 1600 g of Al(NO3)3 b.) 75 ml of 0.5 M C6H12O6 solution. and for this one I get 6.8g of C6 H12 O6 How ...

**chemistry**

What is the percent by mass of 3.55 g NaCl dissolved in 88 g H2O? 2. A solution is made by adding 1.23 moles of KCl to 1000.0 g of water. What is the % by mass of KCl in this solution? 3. If you have 100.0 mL of a 25% aqueous solution of ethanol, what volumes of ethanol and ...

**chemistry**

You need to determine the concentration of a sulfuric acid solution by titration with a standard sodium hydroxide solution. You have a 0.1896 M standard solution. You take a 25.00 mL sample of the original acid solution and dilute it to 250.0 mL. You then take a 10.00 mL ...

**Chemistry**

What is the boiling point of a 25.20% (m/v) KNO3 solution ? (Kf of water = 1.86 0C/molal) (Kb of water = .52 0C/molal) (molar mass potassium nitrate = 101.10324 g/mole) The density of the solution is 1.09 g/ml What is the molarity of the solution? What is the molality of the ...

**Chemistry**

What is the volume, in milliliters, required to prepare a. 20.0 mL of a 0.250 M KNO3 solution using a 6.00 M KNO3 solution b. 25.0 mL of a 2.50 M H2SO4 solution using a 12.0 M H2SO4 solution c. 0.500 L of a 1.50 M NH4Cl solution using a 10.00 M NH4Cl solution

**math**

A 10% acid solution is to be mixed with a 50% solution to get 200 liters of a 20% solution. How many liters of each solution should be used?

**chemistry**

A potassium permanganate solution containing 1.58 g of KMnO4 per liter is added into 5 ml of an acidified iron (||) sulfate solution .Decolorizing of KMnO4 solution ceases when 10ml of the solution has been added. Calculate the mass of FeSo4.7H2O which has been dissolved in ...

**chem**

suppose you had an unknown solution that contained either dissolved NaOH, NaCl< or NaNO3. you add 4 drops of AgNO3 solution to 4drops of the unknown solution and observed that no solid formed. What can be concluded the unknown solution? why?

**chemistry**

A solution of 0.178 M KOH(28.3 ml) is mixed with 28.9ml of 0.133 M HCl. Assuming that the final solution is the sum of the initial volumes, caculate: a)the molarity of the K+ cation b)the molatiry of the Cl- anion c)the pH of the final solution d)the pOH of the final solution

**Chemistry**

Consider a solution containing 4.35 mM of an analyte, X, and 1.09 mM of a standard, S. Upon chromatographic separation of the solution peak areas for X and S are 3251 and 10075, respectively. Determine the response factor for X relative to S. F=? To determine the concentration...

**chemistry**

What is the percent by mass of 3.55 g NaCl dissolved in 88 g H2O? 2. A solution is made by adding 1.23 moles of KCl to 1000.0 g of water. What is the % by mass of KCl in this solution? 3. If you have 100.0 mL of a 25% aqueous solution of ethanol, what volumes of ethanol and ...

**chemistry**

What is the percent by mass of 3.55 g NaCl dissolved in 88 g H2O? 2. A solution is made by adding 1.23 moles of KCl to 1000.0 g of water. What is the % by mass of KCl in this solution? 3. If you have 100.0 mL of a 25% aqueous solution of ethanol, what volumes of ethanol and ...

**Chemistry**

a solution is made by combining 10.0 ml of 17.5 M acetic acid with 5.54 g of sodium acetate and diluting to a total volume of 1.50 L. a)calculate the pH of the solution. b) how many grams and milliliters of 14.6 M potassium hydroxide needs to be added so pH=pKa? c)what is the ...

**Analytical chemistry**

0.6140 grams of sodium phosphate (Na3PO4) was dissolved in 2 L of water to make a stock solution. 34 mL of this solution is then diluted to 100mL volumetrically to prepare the final solution. Calculate the molarity of phosphate ions in this solution. Answer to 5 decimal places.

**Math **

Melanie needs 75% of sugar solution to conduct an experiment.However she only has 40% and90% sugar solution available .how much each solution must she use in order to obtain 60L of the75% of solution? Please answer now , it's very important!!

**Chemistry**

A student has 100.0 mL of an unknown solution of Vitamin C. She removes 1.00 mL of this solution, dilutes it to 50.0 mL, and titrates this second solution with an iodine solution solution that 8.5x1^-4 M. 6.60 mL of iodine solution is required to reach the endpoint. 1. How ...

**Chemistry**

A student has 100.0 mL of an unknown solution of Vitamin C. She removes 1.00 mL of this solution, dilutes it to 50.0 mL, and titrates this second solution with an iodine solution solution that 8.5x1^-4 M. 6.60 mL of iodine solution is required to reach the endpoint. 1. How ...

**Chemistry**

Assume you have prepared 100.0 mL of a buffer solution using 0.400 mol of acetic acid (pKa = 4.74) and 0.400 mol of sodium acetate. The pH of this buffer solution is initially 4.74. After preparing this buffer solution, you added 55.0 mL of a 1.10 M NaOH solution to your ...

**analytical chemistry**

your lab possesses a stock solution of NaOH whose concentration is approx. 0.1M. you prepare a secondary solution by diluting 15.00mL of this stock solution to a total volume of 250.0 mL. you titrate a 50.00mL aliquot of the secondary solution with a hydrochloric acid solution...

**Chemistry**

Hydrogen peroxide, H2O2, solution can be purchased in drug stores and used as an antiseptic. A sample of such a solution weighing 1.00 grams was acidified with sulfuric acid and titrated with .02000 M solution of KMnO4. The unbalanced reaction is H2O2(aq) + MnO4-(aq)--> O2(...

**HELP MATH PLEASE**

You have two beakers of acid solution. One beaker contains a 17% acid solution, and the other beaker contains a 91% ACID SOLUTION. How many liters of the 17% acid solution must you mix with the 91% acid solution to make 2 liters of a 56% acid solution? write the answer correct...

**Chemistry**

A pH = 7.6 buffer is needed in the lab. This buffer is made by first dissolving 17.42 g K2HPO4 in 600 mL of water. What is the pH of this salt solution? This solution of course will be too basic becuase we only have the base of the buffer present. What must the value of the ...

**Chemistry**

The reaction of a metal ion, M^2+, with EDTA is given in the following equation: M^2+(aq) + Y^4-(aq) <==> MY^2-(aq) The EDTA was standardized with a 0.04 M Zn^2+ solution. 25.05 mL of EDTA solution was used to titrate the Zn^2+ solution. From this standardization, ...

**Chemistry**

Silver nitrite, AgNO2 (47.8 mg), was dissolved in water to make 10.00 mL of solution. Then 3.00 mL of that solution was used to make a new solution with a total volume of 1.000 L. What was the concentration of the silver ion in the final solution?

**Chemistry**

Silver nitrite, AgNO2 (47.8 mg), was dissolved in water to make 10.00 mL of solution. Then 3.00 mL of that solution was used to make a new solution with a total volume of 1.000 L. What was the concentration of the silver ion in the final solution?

**Chemistry**

Calculate mole solute in solution? I added an amount of an unknown sample to a solution. I found that the molality of the solution is 0.085m and there is 0.0156kg of solvent. Calculate the moles of solute present in solution? Thanks!

**Chemistry**

56mL of a stock solution of hydrobromic acid, HBr, is added to 85mL of water, yielding a solution having a pH of 1.0. What was the molarity of the stock solution? I know Molarity = moles of solute/ liters of solution

**Honors Chemistry**

An aqueous solution of NaCl has a concentration of .500 M. 35.0 mL of this solution is allowed to evaporate to a volume of 20.0 mL. a) Is the solution more concentrated or more dilute afterwards? b) What is the new concentration of the solution?

**Chemistry**

Calculate mole solute in solution? I added 0.2968g of an unknown to a solution. I found that the molality of the solution is 0.085m and there is 0.0156kg of solvent. Calculate the moles of solute present in solution? Thanks!

**Math quick help anyone**

1. I'm given a slope of 1/4 and a set of 2 points each: p: (-12,6) & Q: (8,w) .find the value of w. what if the slope was -1/4, then what would the value of w be 2. What is the solution to these equations: 3x-2y-8=0 9x-6y-42=0 One solution, no solution or infinite solution or ...

**math**

suppose that x liters of 36% acid solution are mixed with y liters of a 50% solution to obtain 100 L of a 37% solution. One equation is a system for solving this problem is x+y=100. which of the following is the other solution?

**Chemistry**

A solution contains 15 g non-volatile non-electrolyte solute C6H14O6 dissolved in 500 g of water at 40 c. Calculate (A)Vapor pressure of the solution. (B)Boiling point of the solution. (C)Freezing point of the solution.

**Chemistry**

A 2.7 M solution of phosphoric acid (H3PO4) is to be reacted with a 7.5 M solution of sodium hydroxide to make sodium phosphate and water. How many L of the H3PO4 solution will react with 0.662 L of the NaOH solution

**chemistry**

A 25.00 mL solution of potassium nitrate (KNO3) was diluted to 125.0 mL, and 25.00 mL of this solution were then diluted to 1.000 103 mL. The concentration of the final solution is 0.00421 M. Calculate the concentration of the original solution.