Chemistry - October 2007

Saccharin (C7H5NO3S) is sometimes dispensed in tablet form. Ten tablets with total mass of 0.5369 g were dissolved in water. They were oxidized to convert all the sulfphur to sulphate ion, which was precipitated by adding an excess of barium chloride solution. The mass of BaSO4 obtained was 0.5118 g.

What is the average mass of saccharin per tablet in mg?
What is the average mass percent of saccharin in the tablets?


I'm not sure if I'm on the right track:
.5032gBaSO4 / 233.33g =.001085mol BaSO4
.001085mol * 32.07gS=.03480gS

Not sure where to go from there. Can anyone help?

2007-10-02 12:08:45 · 1 answers · asked by Nhat t 1

specifically under a COLD fusion reaction...or when the Hindenburg blew up (if it was a pure oxygen environment)

2007-10-02 12:06:14 · 3 answers · asked by Anonymous

i have to do a science project and i think the correct answer is hot, but when i did it the room temperatures flowed faster and further on the plate then the hot. can someone tell em what is the correct answer?

2007-10-02 12:05:00 · 3 answers · asked by GEARS OF GLITCHES 2

In my chemistry class i have to make a stuffed mole using a pattern. My mole has to have a name and be dressed up to relate to the name. the name has to have mole in it. I need some help, so if you have any ideas let me know. thanks so much

2007-10-02 11:59:58 · 13 answers · asked by softballjcsbabe 2

mixture of oil and vinegar salad dressing

seawater

soda pop

---------------------------------

I know that seawater is probably heterogenous, and that the oil-vinegar mixture may be hetero. as well, but i just wanted to verify my responses.

Thanks!

2007-10-02 11:17:32 · 1 answers · asked by smartballa4life 1

Barium sulfide is one product of the reaction between hydrosulfuric acid and barium hydroxide; the other is water. Write the chemical reaction. including the formulas for the reactants and products.


Not sure of this. Please Help. Thanks! :)

2007-10-02 11:14:02 · 1 answers · asked by CrimsonRider 1

This is for a homework assignment that is due soon... If someone would help me, it would be much appreciated!

2007-10-02 10:46:49 · 2 answers · asked by ghike27 2

2007-10-02 10:43:31 · 1 answers · asked by koollook 1

2007-10-02 09:57:37 · 3 answers · asked by Anonymous

2007-10-02 09:54:14 · 1 answers · asked by Claire H 1

How do you seperate the elements in the air and what parts cannot be seperated ?

2007-10-02 09:39:25 · 1 answers · asked by Anonymous

Aspartme has been used as an artificla sweetner.Identify the functional groups in the aspartme molecule shown. Predict, giving reasons whether or not the substance is soluble in water and other fatty tissues in our body.

2007-10-02 09:39:15 · 1 answers · asked by saif a 1

Br- + MnO4- <--> MnO2 + BrO3- (Basic)
which one is oxidized and which one is reduced? I am so confused with this, so an explanation for this would be much appreciated. thanx!!

2007-10-02 09:37:12 · 1 answers · asked by miss_frd 1

When a solution of nitric acid and sodium hydroxide are mixed, what precipitate if any is formed?

a)No precipitate. This is a neutralization reaction. Water is formed and nitrate and sodium ions move throughout the solution.

b)Sodium nitrate, NaNO3 (s) and water are formed

c)Sodium nitrate, NaNO3 (s)

d)No reaction

When a solution of sodium sulfide and iron (III) chloride are mixed, what precipitate if any is formed?

A)No precipitate
B)Iron (III) sulfide, Fe2S3 (s)
C)Iron (III) sulfide, Fe2S3 (s) and Sodium chloride, NaCl (s)
D)Sodium chloride, NaCl (s)

2007-10-02 08:48:03 · 2 answers · asked by Anonymous

12. Which of the following formulas is incorrect?
A. Al2(SO4)3
*B. AlOH3
C. Ca(OH)2
D. (NH4)2S

13. Which of the following formulas is incorrect?
*A. Fe3Cl
B. N2O3
C. Br2
D. H2CO3

14. Which of the following is the name for this compound: Ca(OH)2
A. carbon oxygen hydrogen
B. carbon oxide
C. calcium hydrogen oxide
*D. calcium hydroxide

15. A colorless, odorless gas combines with a magnetic, metallic element. What can you predict about the product?
A. It will also be magnetic
B. A gas and a solid produce a liquid
C. The compound will be shiny and odorless
*D. It will likely have different properties, but they can't be predicted without more information

16. An atom of magnesium has two valence electrons. It will most likely react with one atom of __, which contains __ valence electrons.
A. carbon, 4
B. nitrogen, 5
*C. oxygen, 6
D. chlorine, 7

17. Nitrogen atoms each have five valence electrons. How many pairs of electrons must be shared in a molecule of N2?
A. 1
B. 3
*C. 4
D. 6

2007-10-02 08:12:27 · 2 answers · asked by Anonymous

6. Which of the following are definitely in atoms of the same element?
*A. 3 protons, 3 neutrons and 3 protons, 4 neutrons
B. 3 protons, 3 neutrons and 4 protons, 4 neutrons
C. 4 protons, 4 neutrons and 3 protons, 4 neutrons
D. 3 protons, 4 neutrons and 4 protons, 3 neutrons

7. An atom of iron contains 26 electrons. How many energy levels are needed to contain these electrons?
A. 1
B. 2
C. 3
*D. 4

8. The atomic number of chlorine is 17. How many valence electrons does an atom of chlorine have?
A. 2
*B. 7
C. 8
D. 17

9. Which of the following is an example of periodicity?
*A. eating breakfast
B. hitting a home run
C. writing a letter
D. sneezing

10. A certain element is a gas and does not conduct electricity or heat. Which of the following is a possible number of valence electrons for the atoms of this element?
A. 1
B. 2
C. 3
*D. 6

11. Based on its position in the periodic table, the most likely charge of an iodine ion is?
*A. 1+
B. 1-
C. 2+
D. 7-

2007-10-02 08:11:02 · 2 answers · asked by Anonymous

1. Which of the following is not an example of a model?
*A. a floor lamp
B. a globe
C. a road map
D. a wind tunnel

2. A 1-g sample of the compound hydrogen chloride was analyzed and found to be 2.74 percent hydrogen and 97.3 percent chlorine. What percentage of hydrogen is present in a 2-g sample of hydrogen chloride?
A. 1.37%
*B. 2.74%
C. 5.48%
D. 97.3%

3. The atomic number of an element whose atoms have 9 electrons and 1 neutrons is?
*A. 9
B. 19
C. 1
D. 18

4.One isotope of carbon has 6 protons and 6 neutrons. The number of protons and neutrons of a second isotope of carbon would be?
A. 7 and 6
*B. 6 and 7
C. 7 and 7
D. 6 and 6

5. If 9. g of water contain 1.0 g of hydrogen, what mass of oxygen is contained in 36 g of water?
A. 4.0 g
B. 8.0 g
C. 10.0
*D. 32 g

2007-10-02 08:09:11 · 2 answers · asked by Anonymous

17. Nitrogen atoms each have five valence electrons. How many pairs of electrons must be shared in a molecule of N2?
A. 1
B. 3
C. 4
D. 6

18. A tug-of-war in which neither side is able to move the other side could be used to model a(n) __.
A. covalent bond
B. crystal
C. ionic bond
D. transfer of electrons

19. A white solid is heated in a test tube. The solid slowly changes color to a grayish power, and a gas escapes from the test tube. Is the white solid an element of a compound?
A. t must be an element since it underwent a chemical change
B. It must be an element since it underwent a physical change
C. It must be a compound since it broke down into two new substances
D. Cannot be determined

20. Find the error in the equation and correct it so the equation would be correctly balanced:
Ca(s) + 2H2O(l) --> CaOH2(aq).
A. Ca2(s)
B. H2O(l)
C. Ca(OH)2(aq)
D. both b and c

2007-10-02 07:58:20 · 5 answers · asked by Anonymous

2007-10-02 07:56:39 · 1 answers · asked by Anonymous

what would you multiply "molecules of N2O" by to get the units "grams of N2O" ?

2007-10-02 07:53:31 · 2 answers · asked by sunnydaze34509xoxo 2

2007-10-02 07:38:36 · 1 answers · asked by Anonymous

2007-10-02 07:37:31 · 1 answers · asked by Anonymous

2007-10-02 07:36:46 · 4 answers · asked by the ugly truth 2

What volume (in mL) of 0.127 M AgNO3 is required to react completely with 33.92 mL of 0.0750 M FeBr2?

2 AgNO3 + FeBr2 → 2 AgBr + Fe(NO3)2

I got 40.0 mL as the volume. Is this right?

2)How many grams of AgBr are formed?

2007-10-02 07:28:05 · 3 answers · asked by Anonymous

2007-10-02 07:21:54 · 11 answers · asked by peachmelba 2

what is forerun in a distillation process? Why do we discard forerun when distilling?

2007-10-02 07:19:04 · 2 answers · asked by Anonymous

How much Na2SO4, in grams, must be dissolved in water to produce 77.0 mL of 0.224 M Na2SO4 solution?

2007-10-02 07:16:29 · 1 answers · asked by Anonymous

2007-10-02 07:16:26 · 2 answers · asked by chizoba u 1

plz answer the following questions and show working. thanks for your help in advance!

a) what is the gram formula mass of Mg(NO3)2 (show working)
b) how many moles in 16g CuO
c) what concentration of solutions is obtained if 4.0g of NaOH is dissolved in water and made up 250cm^3 of solution

2007-10-02 06:58:23 · 4 answers · asked by S 1

HCl+Fe->
HCl+MgO->
HCl+Al(HO)3->
?????????????

2007-10-02 06:50:16 · 3 answers · asked by THE BMW DUDE 1