Saturday

October 22, 2016
Number of results: 31,139

**Chemistry**

A volume of 150mL of 0.35M HCl is to be prepared from 80% HCl stock solution. (Density of HCl = 1.191g/mL). Calculate the molarity of 80% HCl stock solution.

*August 9, 2013 by K*

**Chemistry**

Question: how do you dilute something with a huge concentration to the same thing with a smaller concentration? For example: How do you dilute a 36 M solution of NaOH to a 6 M solution of NaOH?

*September 2, 2014 by K*

**180g/l**

I want to make up a 180g/l solution acid using 98% Sulphuric Acid. How much H2SO4 do I use should I make a stock solution first.

*September 22, 2014 by Jillian*

**Please check my math questions.**

I only need y'all to check my responses. Thanks in advance! Is (0,3) a solution to the equation y=x+3 Yes**My choice No Is (1,-4) a solution to the equation y=-2x Yes No**My choice

*September 30, 2015 by Derpy Pegasus*

**Math**

1. what is the solution of 87 + (-396)? A 183** B -183 C 9 D -9 2. Evaluate: -12 x 3 =? A 36 B -36** C 4 D -4 3. Evaluate: -20 -10 =? A 200 B -200 C 2 D -2*** 4. Select all the problems that have a solution that is negative. -8 + 10 = ? 8 x (-2) +? -4 (-2) = ? -100 + 99...

*September 10, 2016 by Frank *

**Thermochemistry**

When 1.477 mole of an inorganic salt were dissolved in 1.00 L of water in a constant pressure solution calorimeter, the temperature of the calorimeter changed from 25.00oC to 24.40 oC. The total heat capacity of the calorimeter including all its contents was 2.18 kJ oC-1 What ...

*June 12, 2009 by Douglas*

**chemistry**

2.Glycolic acid is often used in facial peels and has a Ka of 1.5x10^-4. If a movie star is to have a solution of pH 2.1 applied to her face at night, what concentration of glycolic acid solution should be made up (assuming that it is a monoprotic acid, and that it dissolves...

*July 6, 2010 by GWM*

**algebra**

A man invested half of his money at 5%, one-third of his money at 4%, and the rest of his money at 5.5%. If his total investment income was $570, how much had he invested? and please show me the solution to solve this problem. thanx sorry bobpursly I cant understand your ...

*February 25, 2012 by aj*

**Chemistry**

If all the H2O2 in 25mL of a 3% solution of H2O2 decomposed, calculate the diameter of a sphere that would contain the resulting O2 at 1 atm and 296K. I understand how to do the problem if I have moles but I am not sure how to get moles. I thought n=0.075moles because 3% ...

*February 17, 2015 by Caroline*

**Statistics **

Use the 5-step hypothesis testing framework to answer the following 2 questions: Step One: Stating the hypothesis Step Two: Choosing the appropriate test statistic Step Three: Developing a decision rule Step Four: Calculating the value of the test statistic Step Five: Stating ...

*February 19, 2015 by Shayna*

**chemistry**

Which has more grams of NaCl? A 2 molar solution in 2 Liters, or a 3 molar solution in 1.5 Liters?

*July 10, 2011 by g*

**Chemistry**

The pH of a 0.10 M solution of a certain acid is 3.25 at 25C. What is the pH of a 0.010 M solution of the same acid at the same temperature?

*July 5, 2013 by Nat*

**Chemistry**

The pH of a 0.10 M solution of a certain acid is 3.25 at 25C. What is the pH of a 0.010 M solution of the same acid at the same temperature?

*July 5, 2013 by Nat*

**Chemistry**

The pH of a 0.10 M solution of a certain acid is 3.25 at 25C. What is the pH of a 0.010 M solution of the same acid at the same temperature?

*July 5, 2013 by Nat*

**chemistry**

how to make 3.0 liters of a 0.98 molar HCl solution from a 10.5 molar HCl stock solution.

*September 18, 2013 by florence*

**Alg**

order your answers from smallest to largest x, then from smallest to largest y. If there is no solution, enter NO Solution 2x^2+3y^2=48 x^2-y^2=4 (x,y)= ( , ) (, ) (x,y)= ( , ) (, ) (x,y)= ( , ) (, ) (x,y)= ( , ) (, )

*May 2, 2014 by K*

**AP chemistry**

The specified heat capacity of silver is 0.24 J/C.g. Please help with this Ap chem quastion.? a. Calculate the energy required to raise the temperature of 150.0 g Ag from 273 K to 298. b. Calculate the energy required to raise the temperature of 1.0 mol Ag by 1.0C (called the ...

*October 23, 2010 by Nardos*

**AP chemistry**

The specified heat capacity of silver is 0.24 J/C.g. Please help with this Ap chem quastion.? a. Calculate the energy required to raise the temperature of 150.0 g Ag from 273 K to 298. b. Calculate the energy required to raise the temperature of 1.0 mol Ag by 1.0C (called the ...

*October 23, 2010 by Nardos*

**Chemistry**

How much water needs to be added to 150mL of an 0.75 molar solution of lithium phosphate to make the solution 0.625 molar? I came up with 70.31mL Can you someone just check this for me please? you want to dilute it 75/62.5, so you are diluting it a factor of 1.2, so add .2 ...

*February 26, 2007 by Kellie*

**Pre Cal---Fix to the question below**

Let P be the point on the unit circle U that corresponds to t. Find the coordinates of P and the exact values of the trigonometric functions of t, whenever possible. (If there is no solution, enter NO SOLUTION.) 4pi = ( , ) sin(4pi) = cos(4pi) = tan(pi) = cot(pi) = sec(4pi...

*February 9, 2010 by Karmen*

**Chemistry**

Hello, I have a question about something we learned in chemistry today. We've been going over Ka/Kb table values, and using them to determine if a solution is acidic, basic or neutral. One of the compounds (in aqueous solution) are NH4OCl (aq), which is supposedly basic. Can ...

*May 18, 2010 by Sally*

**chemistry**

what volume (in ML) of a 0.150 M HNO3 solution is required to completely react wtih 35.7 mL of a 0.108 M Na2CO3 solution according to the following balanced chemical equation? Na2CO3(aq) + 2 HNO3(aq) --> 2NaNO3(aq) + H2O(l) then, in the reaction above, what mass (in grams) ...

*June 21, 2010 by samantha*

**science**

Destiny is using a nutrient solution to use in her garden.She places the powder in a watering can.Then she adds the water.Which would dissolve the powder the fastest? A.SHAKING THE CAN VIGOROUSLY B.STIRRING THE SOLUTION SLOWLY C.TILTING THE CAN CAREFULLY FROM SIDE TO SIDE D....

*October 25, 2011 by Harry*

**Science**

Destiny is using a nutrient solution to use in her garden.She places the powder in a watering can.Then she adds the water.Which would dissolve the powder the fastest? A.SHAKING THE CAN VIGOROUSLY B.STIRRING THE SOLUTION SLOWLY C.TILTING THE CAN CAREFULLY FROM SIDE TO SIDE D....

*October 25, 2011 by Harry please please*

**Analytic chemistry**

A solution of HClO4 was standardized by dissolving 0.3745 g of primary standard grade HgO in a solution of KBr. The liberated OH- required 37.99 mL of the acid to be neutralized. Find the molarity(M) of HClO4. The given balanced chemical equation is: HgO + 4Br- + H20 ===> ...

*January 21, 2015 by Smile*

**Chemistry**

What is the pH, pOH, [H+] and [OH-] for a solution that contains 5.25 x 10^-3 moles of HCl dissolved in 3.25 L of water? I was gone the day my teacher explained this and I'm completely lost on what to do. An outline of steps needed to solve the problem would be helpful. Please...

*May 8, 2015 by Joey*

**chemistry**

1) All of the following are oxidation-reduction reactions except (a) 2Al(s) + Fe2O3(s) A12O3(s) + 2Fe(s) (b) (NH4)2Cr2O7(s) Cr2O3(s) + N2(g) + H2O(1) (c) Cu(s) + 2H2SO4(aq) CuSO4(aq) + SO2(g) + 2H2O(1) (d) Hg(NO3)2 + 4KI K2HgI4(aq) + 2 KNO3(aq) (e) 2Na(s) + 2H2O(1...

*April 10, 2010 by write2khin*

**econ 2110**

Suppose that we want to test whether the mean selling price of houses with is the same as the mean selling price of houses without a garage. We collect two samples and obtain the following information: Houses with garage Sample size: 71 Mean selling price (in thousands of ...

*September 19, 2014 by katlyn*

**Chem**

Please tell me if these are right! What are the [H3O+] and [OH-] for a solution with the following pH values? a. 10.0 I got 1.0*10^-10 for [H3O+] and 1.0*10^-4 for [OH-] b. 5.0 I got 1.0*10^-5 for [H3O+] and 1.0*10^-9 for [OH-] c. 7.00 I got 1.0*10^-7 for [H3O+] and1.0*10^-7 ...

*December 8, 2010 by Jessica*

**statistics**

Of the 6796 students in one school district, 1537 cannot read up to grade level. Among a sample of 812 of the students from this school district, 211 cannot read up to grade level. Find the sample proportion of students who cannot read up to grade level. A. 0.14 B. 0.26 C. 211...

*April 17, 2015 by Jane*

**math**

Of the 6796 students in one school district, 1537 cannot read up to grade level. Among a sample of 812 of the students from this school district, 211 cannot read up to grade level. Find the sample proportion of students who cannot read up to grade level. A. 0.14 B. 0.26 C. 211...

*April 17, 2015 by HELP*

**Chemistry**

Phenol dissolved into sodium hydroxide solution to give another solution A. What would be formed when A reacted with phenylamine/nitrous acid mixture , butylamine/nitrous acid mixture and ammonia/ nitrous acid respectively ? The resulting solution were brown , red and ...

*December 6, 2008 by initial D*

**Analytical Chemistry**

Any help/advice on answering this question would be a big help! :) The analysis of lead (Pb) in a sample of solder was carried out using atomic absorption spectroscopy as follows. 1.013 g of solder was completely dissolved in a small volume of nitric acid and the solution made...

*April 27, 2015 by Chris*

**math**

The five number summary, the sample size, and the largest and smallest data values in the tails of the distribution for a sample of data are given below. Five number summary: left-parenthesis 10 comma 12 comma 15 comma 18 comma 29 right-parenthesis; n equals 200 Tails: 10 ...

*February 2, 2016 by JANET*

**physics**

Radioactive nuclei are produced in an irradiated sample at the rate of 10 s-1. If the number in the sample builds up to a maximum of 1000, calculate the mean life and the half-life of the radioactive nuclei Using dN / dt = P - λ N dN / dt = 1000n /10/ 1 = 100 P - λ N...

*August 18, 2014 by Ali*

**Chemistry**

A colourless solution contains one type of ion. When one adds dilute HCl to it, a white precipitate initially forms. However, once more of the HCl solution is added, the precipitate dissolves. Explain why the ion is Pb2+ and not Al3+, Hg22+, Cu2+ nor Ag+. I know Cu2+ is not an...

*September 3, 2007 by Vic*

**math elimination method**

elimination method really confuses me. solve by elimination method 5r -3s = 17 3r + 5s =17 A. solution is ______ (ordered pair, integer or fraction) B. Infinitely many C. No Solution

*July 9, 2010 by Lorri*

**chemistry**

A aqueous solution of acetic acid with a density of 1.25 g/ml is 30.0% by mass HC2h3O2 (MM=60.0) Compute the molarity of this solution. I figured out that if you divide 30.0 by the molar mass 60.0g which gives you .5 mol. I cannot seem to figure out what i change 1.25 g/ml ...

*February 23, 2009 by Aimee*

**Chem**

How do I do this problem Assume you dissolve 2.56 g of malic acid, C4H6O5, in half a liter of water (500.0 g). Calculate the molarity, molality, mole fraction, and weight percent of acid in the solution. (Assume the final volume of the solution is 500. mL)

*July 24, 2011 by Ann*

**precal**

Solve the given equation. (Enter your answers as a comma-separated list. Let k be any integer. Round terms to three decimal places where appropriate. If there is no solution, enter NO SOLUTION.) 2 cos2 θ − cos θ − 1 = 0

*October 22, 2011 by stellar*

**algebra**

1.Write a quadratic equation in the variable x having the given numbers as solutions. Type the equation in stadard form ax^2+bx+c=0 Solution 7, only solution 2.The width of a rectangle is less than the length. The area is 4ft^3. Find the length and the width.

*December 17, 2011 by lisa*

**Chemistry**

0.000333 g fluorescein (332.32 g/mol) is dissolved in 225 mL solution of ethanol. The density of ethanol is 0.785 g/mL. What is the concentration of the solution in molarity (M)? How many ppm? I already know that the molarity is 4.45E-6. I just need help on trying to find the ...

*July 16, 2012 by Vince*

**Physics**

A collapsible plastic bag contains a glucose solution. If the average gauge pressure in the vein is 1.21 103 Pa, what must be the minimum height h of the bag in order to infuse glucose into the vein? Assume the specific gravity of the solution is 1.03.

*November 7, 2012 by Amelia*

**Chemisty**

Consider a 1.50 L aqueous solution of 3.75 M NH3, where 17.5 g of NH4Cl are dissolved. To this solution, 5.00 g of MgCl2 are added. a. What is [OH-] before MgCl2 is added? b. Will a precipitate form? c. What is [Mg2+] after equilibrium is established? I don't need the answers...

*November 14, 2013 by Olivia*

**Health**

An accident chain always contains the 1:problem 2:unsafe action 3:solution 4:witnesses I think it is #3 solution..is this correct? A common emergency is 1:shock 2:choking 3:cardiac arrest 4:ankle sprain I pick #4 ankle sprain..Is this correct?

*May 19, 2015 by Marylyn*

**Statistics **

What price do farmers get for their watermelon crops? In the third week of July, a random sample of 52 farming regions gave a sample mean of = $6.68 per 100 pounds of watermelon. Assume that is known to be $1.94 per 100 pounds. A farm brings 35 tons of watermelon to market. ...

*July 7, 2012 by Desperate *

**biology help plz?????????????????**

Complete the following paragraph relating to the enzyme, βgalactosidase. This enzyme hydrolyses the disaccharide lactose to constituent monosaccharides, galactose and glucose. Drag and drop the appropriate words into the correct space. For white spaces in the sentences ...

*February 28, 2013 by centya*

**science**

Would you expect the dissolved oxygen concentration of water samples taken from a lake at 7 am to be higher or lower than samples takn at 5 pm? I feel like there may be more dissolved oxygen in the sample taken at 7 am because photosynthesis probably took place and oxygen was ...

*May 7, 2008 by Jin*

**Chemistry**

Which of the following statements is (are) true? A. The vapor pressure of CO2 is lower than the vapor pressure of water. B. Sea water has a lower vapor pressure than distilled water. C. The vapor pressure of 1 m NaCl is higher than the vapor pressure of 0.5 m KNO3, assuming ...

*August 30, 2010 by kendra*

**1 chem question**

A base has a Kb of 2.5 x 1011. Which of the following statements is true? This is a concentrated base. This base ionizes slightly in aqueous solution. This is a strong base. An aqueous solution of this base would be acidic. (do explain. i don't understand this one)

*February 14, 2012 by Sara*

**Chemistry-Pressure**

The wastewater solution from a factory containing high levels of salts needs to be diluted before it can be released into the environment. Therefore, two containers of waste solution are separated by a semipermeable membrane and pressure is applied to one container, forcing ...

*April 28, 2013 by Jonah*

**Chemistry **

To what volume should you dilute 124mL of an 8.10M CuCl2 solution so that 49.0mL of the diluted solution contains 4.81g CuCl2? Molar Mass of CuCl2= 134.45 g/mol Convert: 4.81g * (1mol/ 13.45g CuCl2)= 0.0358mol CuCl2 [CuCl2]= M= mol/L= (0.0358mol/ 49ml) * (1000mL/1L)= 0.7306M ...

*February 21, 2015 by Nyle*

**statistics**

A committee of three people is to be formed. The three people will be selected from a list of five possible committee members. A simple random sample of three people is taken, without replacement, from the group of five people. Using the letters A, B, C, D, E to represent the ...

*July 16, 2014 by kenny*

**AP Chemistry**

Calculate the volume of a 36% solution of hydrochloric acid (density = 1.50g/mL, molar mass = 36 g/mol) required to prepare 9 liters of a 5 molar solution. A. 1 liter B. 2 liters C. 3 liters D. 4 liters E. 5 liters

*September 15, 2011 by Stephanie*

**chemistry**

In a constant-pressure calorimeter, 75.0 mL of 0.830 M H2SO4 was added to 75.0 mL of 0.310 M NaOH. The reaction caused the temperature of the solution to rise from 23.20 C to 25.31 C. If the solution has the same density and specific heat as water, what is ΔH for this ...

*February 6, 2013 by Brianna*

**chemistry**

In a constant-pressure calorimeter, 75.0 mL of 0.950 M H2SO4 was added to 75.0 mL of 0.460 M NaOH. The reaction caused the temperature of the solution to rise from 21.13 C to 24.26 C. If the solution has the same density and specific heat as water, what is ΔH for this ...

*April 3, 2013 by Lyndzey*

**Physics**

In a constant-pressure calorimeter, 75.0 mL of 0.810 M H2SO4 was added to 75.0 mL of 0.390 M NaOH. The reaction caused the temperature of the solution to rise from 22.68 C to 25.34 C. If the solution has the same density and specific heat as water, what is ΔH for this ...

*October 20, 2014 by KTM*

**Math**

Suppose that an automobile parts wholesaler claims that .5 percent of the car batteries in a shipment are defective. A random sample of 200 batteries is taken, and four are found to be defective. (a) Use the Poisson approximation to find the probability that four or more car ...

*February 11, 2012 by Krista*

**Statistics**

Suppose that an automobile parts wholesaler claims that .5 percent of the car batteries in a shipment are defective. A random sample of 200 batteries is taken, and four are found to be defective. (a) Use the Poisson approximation to find the probability that four or more car ...

*February 11, 2012 by Krista*

**Chemistry Lab**

Using the molarity of fromic acid (HCOOH): 0.1033 Calculate the percent by mass of fromic acid in unknown solution. Assume the density of aqueous fromic acid solution is 1.000 g/mL. Need help setting up this problem. Thank you.

*May 16, 2011 by Thao*

**chemistry**

1) If the kelvin temperature of a gas sample in a steel tank increases to three times its original value , what will happen to the pressure? I think It will increase. Is this correct? By what factor does the gas pressure change? 2) A gas sample at a constant pressure shrinks ...

*March 29, 2008 by Jason*

**Math**

Based on the information given for each of the following studies, decide whether to reject the null hypothesis. For each, give (a) the Z-score cutoff (or cutoffs) on the comparison distribution at which the null hypothesis should be rejected, (b) the Z score on the comparison ...

*July 23, 2012 by Kathy*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...

*November 28, 2013 by Katy*

**chemistry**

What will be the final pH value if you mix 50ml HCl (aqueous solution, pH=0.5) and 40ml NaOH (aqueous solution, pH=12). Hint: convert pH value to concentration of acids/base, then consider the neutralization reaction, then find out the resulting pH value. Please show me your ...

*April 4, 2013 by Anonymous*

**chemistry**

A piece of aluminium weighing 2.7 gm is heated with 75 ml of H2SO4(specific gravity 1.18 containing 24.7 percent H2SO4 by weight.)After the metal is carefully dissolved,the solution is dissolved to 400ml.Calculate tne molarity of the free H2SO4 in the resulting solution.(IIT ...

*July 9, 2013 by Anonymous*

**Algebra**

Help!! I am having difficulty with a problem for hours now and if I could get some help, my head might stop pounding.Solve each system graphically. if a system has an infinite number of solutions, use set builder notation to write the solution set. If a system has no solution...

*January 2, 2015 by slomo*

**chemistry**

. If 20.0 mL of a 0.10 M HCl solution is mixed with 10.0 mL of a 0.25 M HCl solution, what is the final concentration of HCl after the two solutions are mixed?

*September 18, 2007 by sarah*

**Science**

Rubbing alcohol is a solution of 70 percent alcohol and 30 percent water. In the alcohol solution, which is the solute and which is the solvent? Explain.

*May 7, 2008 by Amber-NEED HELP!!!*

**maths**

how do you know when an equation has infinitely many solution? How do you know when an equation has no solution

*July 29, 2008 by olabisi*

**college**

How do you know when an equation has infinitely many solution and when an equation has no solution?

*November 20, 2009 by Linda*

**chemistry**

Aqueous solution with a pH of 10.6 is diluted from 1 L to 1.5 L. What is the pH of the diluted solution?

*March 14, 2010 by elizabeth*

**chemistry**

A glucose solution contains 55.8g of glucose (C6H12O6) in 455g of water. Calculate the freezing poing and boiling point of the solution. (Assume a density of 1.00 g/ml for water. This what I did, I got moles of C6H12O6, 0.89 moles C6H12O6 then I got the mass of the solution ...

*November 4, 2011 by Monique*

**chemisry**

A technician needs to determine the concentration of lead ions in a sample of water a) Suggest a test chemical that can be added to the water sample to preciitate the lead ions. Show a chemical euation for the formation of the precipitate b) after a precipitate forms, it is ...

*August 16, 2010 by Kelsey*

**Chemistry**

Are these correct also? Ammonium Chloride : NH4Cl Nitrogen Dioxide : NO2 Hydroiodice Acid : HI Stannous Iodide : SnI2 Perchloric Acid : HClO4 Sulfur Trioxide : SO3 Chromium (III) Oxide : Cr2O3 Nitric Acid : HNO3 Diphosphorous Pentoxide: P205 Mercurous Chloride : Hg2Cl2 ...

*January 12, 2011 by Anonymous*

**chemistry**

Can anyone help me with these Chemistry questions? I am trying to study for an upcoming test and its just not sinking in as well and I thought. This is Thermochem for a heads up: Suppose 33mL of 1.20M HCl is added to 42mL of a solution containing excess sodium hydroxide in a ...

*December 3, 2009 by Dina*

**Please Check Answers for Health**

Please check my answers because I need to do good at this. 1. When consuming fats the healthiest choice is foods high in? A. saturated fats B. unsaturated fats * C. trans fat D. cholesterol 2. The body's main energy source should come from what essential nutrient? A. protein* ...

*November 6, 2014 by Ella*

**math**

The lengths in inches (x and y) of two fish are related by the equation 5x 4y = 24. The two ordered pairs that follow are solutions to the equation: (4, -1) (12,9) Which statement best evaluates whether these two solutions make sense in this situation? A. The solution (4, -1...

*November 4, 2013 by samone*

**Chemistry**

A base has a Kb of 2.5 x 1011. Which of the following statements is true? A.This is a concentrated base. B.This base ionizes slightly in aqueous solution. C.This is a strong base. D.An aqueous solution of this base would be acidic. My answer is D...?

*February 12, 2013 by Cassie*

**Statistics**

The average mpg usage for a 2004 Ford Expedition 2WD for a sample of 10 tanks of gas was 17.0with a standard deviation of 0.8. For a Ford Explorer 2WD, the average mpg usage for a sample of 10 tanks of gas was 18.5 with a standard deviation of 1.0. (a) Assuming equal variances...

*September 19, 2010 by Kim*

**statistics**

1. A states department of education reports that 12% of the high school students in that state attend private schools. The state university wonders if the percentage is the same in their applicant pool. Admissions officers plan to check a random sample of the over 10,000 ...

*November 17, 2011 by fast eddie*

**statistics**

The following table shows the summary statistic of the cholesterol levels of two groups of men in 2014. From 25 to 40 years old, the mean is 224, standard deviation is 5.5 and the sample size is 12. From 41 to 55 years old, the mean is 230, standard deviation is 7 and the ...

*November 15, 2014 by poon*

**chemistry**

An aqueous solution is made by dissolving 15.6 grams of nickel acetate in 373 grams of water. The molality of nickel acetate in the solution is

*June 20, 2011 by Adanna*

**Algebra**

an equation and two ordered pairs are given. show that each pair is a solution of the equation. Then graph the two pairs to determine another solution. 6x-3y=3; (1,1), (-1, -3)

*July 12, 2011 by Poochie*

**chemistry**

A solution of ammonia and water contains 2.701025 water molecules and 7.601024 ammonia molecules. How many total hydrogen atoms are in this solution?

*October 9, 2011 by Anonymous*

**Chemistry**

What volume (in mL) of 0.45 M Na2SO4 solution is needed to precipitate all the barium, as BaSO4(s), from 14.5 mL of 0.15 M Ba(NO3)2 solution? Ba(NO3)2(aq) + Na2SO4(aq)= BaSO4(s) + 2 NaNO3(aq)

*December 2, 2012 by John*

**Chemistry **

A solution of ammonia and water contains 1.601025 water molecules and 8.501024 ammonia molecules. How many total hydrogen atoms are in this solution?

*October 8, 2014 by R*

**chem**

A solution of ammonia and water contains 3.801025 water molecules and 5.801024 ammonia molecules. How many total hydrogen atoms are in this solution?

*January 21, 2015 by todd*

**Chemistry**

A solution of ammonia and water contains 3.701025 water molecules and 7.101024 ammonia molecules. How many total hydrogen atoms are in this solution?

*September 9, 2015 by Mel*

**Chemistry**

I have 93.954 mL of a generic cola solution. The solution contains: Molarity of H++1.005e-7 Molarity of OH- = 1.005e-7 Molarity of Sucrose(aq) = 6.386e-1 Molarity of Dye= 5.322e-3 Calculate the mass percent, molarity, molality and mole fraction.

*November 3, 2011 by Emily*

**Chem question Redox Stoichiometry**

A 2.80 mol/L solution of iron (II) dichromate is combined with 5.00L of a 2.25 mol/L acidic solution of tin (II) bromide. Calculate the volume of iron (II) dichromate required. FeCr2O7 + SnBr2 --> SnCr2O7 + FeBr2 Is this the right formula? or no?

*May 16, 2007 by Mistra*

**ap chem**

A certain volume of a .50 M solution contains 4.5g of a certain salt. What mass of the salt is present in the same volume of a 2.5 M solution? Indicate the concentration of each ion/molecule: A mixture of 50.0 mL of .2M KClO3 and 25.0 mL of a .20M Na2SO4. How would you answer ...

*September 13, 2007 by lily*

**AP Chem**

A solution of potassium phosphate is mixed with a solution of calcium acetate. I am supposed to write a net ionic equation. Doesn't need to be balanced. Here is what I did: K3PO4(aq) + Ca(C2H3O2)2 --> KC2H3O2 + Ca3PO4 3K+ + PO4-3 + Ca+2 2(C2H3O2-) --> K+ + C2H3O2 + 3Ca+2...

*October 3, 2007 by Please check*

**biochemistry lab**

A) If you make up a solution of 50 mL of 0.1 M TRIS in the acid form, what will be the pH? B) If you add 2 mL of 1M NaOH to the solution in part A, what will be the pH? If it is needed, here is some addition information: TRIS pka= 8.3 mw of TRIS-HCL= 157.6 g/mol; mw TRIS (...

*February 2, 2008 by erin*

**CHEMISTRY..please help..thanks**

Calculate the new molarity if each of the following dilutions is made. Assume the volumes are additive. (a) 52.3 mL of water is added to 27.1 mL of 0.124 M KOH solution (b) 110. mL of water is added to 54.2 mL of 0.808 M NaCl solution ((please show work, thank u so much)

*November 10, 2010 by Jasmin*

**Biology Lab**

Can you please show me how to answer this question using C1V1=C2V2 A scientist receives a vial containing a protein at at concentration of 35mg/ml 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 mg/ml?

*June 17, 2012 by Mandy*

**math**

Ms. Banyas bought adult tickets and childrens tickets to a lacrosse game. She spent a total of $145. The equation that follows describes the relationship between and : 25x + 15y = 145 The ordered pair (4,3) is a solution to the equation. What does the solution (4,3) represent?

*November 4, 2013 by samone*

**chemistry**

Calculate the concentrations of all ions after 50.0 mL of a 0.100 M AgNO3 solution is mixed with 100.0 mL of a 1.00 M Na2SO4 solution.For Ag2SO4 Ksp = 1.2 x 10-5 Do I first do MiVi=MfVf and then using the two concentrations I use ksp value? I'm just so confused.

*April 29, 2015 by Anon *

**math**

The sides of two squares differ by 25cm while the sum of their areas is 2425cm. What is the length of the sides of each square. I know the answer--45&20 but I don't know the step by step solution. (40)-(20)=25 (40)^2+(20)^2=2425 2025+400=2425 Please give the solution Sir & Mam...

*August 15, 2016 by Nimuel*

**Stats**

An article (N. Hellmich. "'Supermarket Guru' Has a Simple Mantra, USA Today, June 19, 2002, p. 70) claimed that the typical super market trip takes a mean of 22 minutes. Suppose that in an effort to test this claim, you select a sample of 50 shoppers at a local supermarket. ...

*August 13, 2008 by Student*

**Math**

An article (N. Hellmich. "'Supermarket Guru' Has a Simple Mantra, USA Today, June 19, 2002, p. 70) claimed that the typical super market trip takes a mean of 22 minutes. Suppose that in an effort to test this claim, you select a sample of 50 shoppers at a local supermarket. ...

*April 20, 2010 by Statistics baby*