Tuesday

January 17, 2017
Total # Posts: 159

**chemistry**

We add excess NaCl solution (58.44 g/mol) to 56 mL of a solution of silver nitrate (AgNO3 169.88 g/mol), to form insoluble solid AgCl. When it has been dried and weighed, the mass of AgCl (143.32 g/mol) is found to be 1.25 grams. What is the molarity of the original AgNO3 ...

*September 19, 2012*

**chemistry**

How many milliliters of a 0.5 molar HCl solution are needed to react completely with 11 grams of zinc according to the following equation? ? HCl + ? Zn ! ? ZnCl2 + ? H2 Answer in units of mL

*September 19, 2012*

**chemistry**

Silver nitrate (AgNO3) reacts with sodium chloride as indicated by the equation AgNO3 + NaCl ! AgCl + NaNO3 . How many grams of NaCl would be re- quired to react with 511 mL of 0.38 M AgNO3 solution? Answer in units of grams

*September 19, 2012*

**chemistry**

What volume of 0.402MK3PO4 is required to react with 43 mL of 0.507 M MgCl2 according to the equation 2K3PO4 + 3MgCl2 ! Mg3(PO4)2 + 6KCl Answer in units of mL

*September 19, 2012*

**chemistry**

How many milliliters of a 0.16 M HCl solution are needed to react completely with 4.8 g of zinc to form zinc(II) chloride? Answer in units of mL

*September 19, 2012*

**ap chem**

A sample of 7.45 grams of NaOH is dissolved into 609 mL of aqueous 0.250 M NaOH (as-sume no volume change). This solution is then poured into 2.18 gallons of water. (You may assume that the two volumes can be added.) What is the concentration of NaOH in the final solution? ...

*September 16, 2012*

**ap**

i think its suppose to be the u symbol thing.

*September 16, 2012*

**ap**

A sample of air contains 38.5 ìg/m3 of beryl- lium dust. How many atoms of beryllium are present in a room with dimensions of 8 feet by 12.9 feet by 17.1 feet? Answer in units of atoms

*September 16, 2012*

**chemistry**

i got 11.098 for the moles for the first part. so do i add .1 to that?

*September 16, 2012*

**chemistry**

How many grams of sucrose (C12H22O11) must be dissolved in 200 g water to make a solution in which the mole fraction of su- crose is 0.1? Answer in units of g

*September 16, 2012*

**chemistry**

Calculate the molality of acetone in an aqueous solution with a mole fraction for ace- tone of 0.171. Answer in units of m

*September 16, 2012*

**chemistry**

How many milliliters of 5.5 M HCl must be transfered from a reagent bottle to provide 23 g HCl for a reaction? Answer in units of mL

*September 16, 2012*

**chemistry**

What mass of MgSO4 · 7H2O is required to prepare 300 mL of a 0.61 M MgSO4 solution? Answer in units of g

*September 16, 2012*

**chemistry**

It takes 62 mL of 0.124 M KOH to neutralize 46.7 mL of H2SO4 solution. What is the concentration of the H2SO4 solution? Answer in units of moles/liter

*September 16, 2012*

**chemistry**

Calculate the molality of CsCl in a 19% by mass aqueous solution.

*September 13, 2012*

**chemistry**

When 0.025 moles of aluminum sulfate are dissolved in enough water to make 115 milliliters of solution, what is the molarity of sulfate ions? Answer in units of M

*September 13, 2012*

**chemistry**

We have an aqueous solution that contains 47% (by mass) of a hypothetical solute Z. The formula weight of the solute Z is 209 g/mol. The density of the solution is observed to be 1.3 g/mL. What is the molarity of Z in this solution? Answer in units of mol/L

*September 13, 2012*

**chemistry**

Sulfuric acid (H2SO4) is a very strong diprotic acid. If 0.062 moles of sulfuric acid is mixed with water to make 200 mililiter of solution, what is the molarity of H+? Answer in units of M

*September 13, 2012*

**chemistry**

How many milliliters of 5.5 M HCl must be transfered from a reagent bottle to provide 23 g HCl for a reaction? Answer in units of mL

*September 13, 2012*

**chemistry**

It takes 62 mL of 0.124 M KOH to neutralize 46.7 mL of H2SO4 solution. What is the concentration of the H2SO4 solution? Answer in units of moles/liter

*September 13, 2012*

**ap chemistry**

What volume of 6.58 M HNO3 is required to prepare 671 mL of a 2.7 M HNO3 solution? Answer in units of mL

*September 13, 2012*

**chemistry**

What mass of MgSO4 · 7H2O is required to prepare 300 mL of a 0.61 M MgSO4 solution? Answer in units of g

*September 13, 2012*

**chemistry**

What volume of 6.58 M HNO3 is required to prepare 671 mL of a 2.7 M HNO3 solution?

*September 13, 2012*

**chemistry**

It takes 62 mL of 0.124 M KOH to neutralize46.7 mL of H2SO4 solution. What is the concentration of the H2SO4 solution?

*September 13, 2012*

**ap chemistry**

Sulfuric acid (H2SO4) is prepared commer- cially from elemental sulfur using the contact process. In a typical sequence of reactions, the sulfur is first burned: S + O2 ! SO2 , then it is converted to SO3 using a catalyst: 2 SO2 + O2 ! 2 SO3 . The resulting SO3 is reacted with...

*September 11, 2012*

**ap chemistry**

i keep getting the wrong answer

*September 11, 2012*

**ap chemistry**

The reaction of 9.5 grams of fluorine with excess chlorine produced 5.9 grams of ClF3. What percent yield of ClF3 was obtained? Answer in units of %

*September 11, 2012*

**ap chemistry**

i got 8.71%

*September 11, 2012*

**ap chemistry**

In the reaction below, 22 g of H2S with excess O2 produced 10 g of sulfur. ?H2S + ?O2 ! ? S + ?H2O. What is the percent yield of sulfur? Answer in units of %

*September 11, 2012*

**ap chemistry**

Sulfuric acid (H2SO4) is prepared commer- cially from elemental sulfur using the contact process. In a typical sequence of reactions, the sulfur is first burned: S + O2 ! SO2 , then it is converted to SO3 using a catalyst: 2 SO2 + O2 ! 2 SO3 . The resulting SO3 is reacted with...

*September 11, 2012*

**chemistry**

A 26.3754 g sample of impure magnesium car- bonate was heated to complete decomposition according to the equation MgCO3(s) ! MgO(s) + CO2(g) . After the reaction was complete, the solid residue (consisting of MgO and the original impurities) had a mass of 15.4638 g. Assum- ing...

*September 10, 2012*

**chemistry**

An ore contains Fe3O4 and no other iron. The iron in a 54.6-gram sample of the ore is all converted by a series of chemical reactions to Fe2O3. The mass of Fe2O3 is measured to be 21.3 g. What was the mass of Fe3O4 in the sample of ore? Answer in units of g

*September 10, 2012*

**ap chemistry**

A 25.2 g of iron ore is treated as follows. The iron in the sample is all converted by a series of chemical reactions to Fe2O3. The mass of Fe2O3 is measured to be 12 grams. What was the percent iron in the sample of ore? Answer in units of %

*September 10, 2012*

**ap chemistry**

If a metal ore contains 21.9% pure metal, how many pounds of pure metal can be obtained from 68 pounds of metal ore? Answer in units of pounds

*September 10, 2012*

**public speaking**

I think it's C Techology. Could I be wrong?

*August 7, 2012*

**algebra**

5-(4y+5)=3+2(4y-6) how do i combine like terms and what do i do with these()?

*April 30, 2012*

**basic dressmaking processes**

Examination 04201701 BASIC DRESSMAKING PROCESSES 1. A Correct 2. D Correct 3. B Correct 4. C Correct 5. A Correct 6. D Correct 7. C Correct 8. B Correct 9. A C PAGE 22 10. D Correct 11. C Correct 12. C Correct 13. A Correct 14. B Correct 15. D Correct 16. C Correct 17. D A ...

*August 30, 2011*

**health**

a 7 yr old boy breaks his tibia and requires immobility by a hard cast for 6 weeks initl it heals. a potential consequence of this therapy is atrophy of the

*June 7, 2011*

**math**

An electronics store receives a shipment of 20 graphing calculators, including 3 that are defective. Four of the calculators are selected to be sent to a local high school. A. How many selection can be made using the originial shipment?

*March 8, 2011*

**health**

the answer is A)presbytopia. I found it on page 25 of the sensory, organs, nervous system, and endocrine system study unit. hope this helps

*January 29, 2011*

**College Physics**

An amusement park mirror shows anyone who stands 2.5 meters in front of it an upright image two times the person's height. What is the mirror's radius of curvature?

*November 17, 2010*

**Physics**

A proton and an electron have the same kinetic energy upon entering a region of constant magnetic field. What is the ratio of the radii of their circular path?

*October 27, 2010*

**2nd grade**

What number am I My tens digit is double my ones digit. I am less than 70 greater than 60? How do u figure this out need help to explain how to get the answer..

*October 11, 2010*

**math**

Number sence What is the number? It is greater than 43 and less than 52. If you add the digit, the sum is 8. write the number word. I need help figuring this out not just the answer but how to get the answer.

*October 11, 2010*

**Dressmaking**

Examination 04281600 PRAC EXER FOR INSTRUC PACK 2 1 D Correct 2. A Correct 3. D Correct 4. A Correct 5. C Correct 6. B Correct 7. D Correct 8. A Correct 9. B Correct 10. B Correct

*July 27, 2010*

**accounting**

I need help wit Acc/225 week 2 and the exercise is 2-5 I have to do a T-account and Trial balance for Pose Pics and it is really confusing me

*June 12, 2010*

**ART**

What are some careers in the visual arts?

*May 21, 2010*

**French immersion grade 5 math perimeters**

My child needs to write out equations for various shapes on grid paper, using French. Finding the perimeter eg:P=(L+L)x2 also finding the Area. The shapes are complex, and I am lookin for help in figuring out how to write the equations properly, using the French. Can you help?

*February 22, 2010*

**9th grade**

How many milligrams are in a kilogram

*December 10, 2009*

**fibers and fabrics**

Examination 04201600 Fibers and fabrics 1. D Correct 2. C Correct 3. B Correct 4. D Correct 5. A Correct 6. D B PAGE 3 7. A Correct 8. C Correct 9. D Correct 10. A Correct 11. D Correct 12. C Correct 13. A Correct 14. B Correct 15. B Correct 16. C Correct 17. A Correct 18. D B...

*December 2, 2009*

**managerial economics**

There is a regression model. E= a+bn. Where E is total earnings of the motion pictyre industry measured in dollars per year and N is the number of tickets sold in December. Dependent variable:E R sqaure 08311 F ration 63.96 P value 0.0001 Variable intercept N parameter ...

*November 23, 2009*

**Reseach paper**

I am taking the same class at Penn Foster.I did find the article on the AMA website. Haven't found any other places with the help I needed. So I will use that article and go from there. Hoping I can find enough of my own words to complete it.

*June 21, 2008*

**math**

7y=2x-5, the x equals what?

*May 25, 2008*

**Criminology Today**

Need presentation to request an increased budget for sex offender rehabilitation programs. An overview of how the competing psychological and sociological explanations of crime would seek to explain the actions of a serial rapist. Give a specific explanation or theory of ...

*March 25, 2008*

**Philosophy**

If Plato had to write a letter to Aristotle about his philisophical viewpoints concerning his philosophies, what do you think he would write about? I need some help with one of my papers. Need ideas, opinions anything. I am having a writers block. Check out these sites for ...

*August 20, 2007*

**Stats**

What happens to the power of the z test, when the standard deviation increases? The deviation from the mean must be larger to obtain the same significance level. I'm not familiar with the term "power" (we don't use that term in physics), but I would guess ...

*December 28, 2006*

**Statistics**

Is a sampling distribution always the same as the curve for a null hypothesis? How does the power of a z test change when sigma increases? Assuming that they are caused solely by chance, sampling distributions will approximate a normal distribution more closely as the size of ...

*December 27, 2006*

**Statistics**

Trying to finish an assignment: What happens to the power of the z test when the standard deviation increases? and Is the shape of a sampling distribution always the same as that of the null hypothesis population? Thanks! As the SD increases, the exactness of the estimate of a...

*December 27, 2006*

**Probability -- Help?**

Sampling one at a time with replacement from a bag with 8 blue, 7 red, and 5 green. What is the probability of getting at least two red in 3 draws? The book says the probability is 0.2818 but doesn't explain why. Any help???? Unfortunately, the probability of picking 3 red...

*December 1, 2006*