Chemistry - November 2006

2006-11-28 06:23:40 · 5 answers · asked by Riotgirl976 1

2006-11-28 06:22:35 · 6 answers · asked by rmmeyyappan 1

2006-11-28 06:22:00 · 3 answers · asked by Riotgirl976 1

2006-11-28 06:02:18 · 4 answers · asked by yoyo 2

For the reaction BaI2 + MgSO4 (aq)BaSO4 precipitates out.Calculate the percent yield (%)if11.083gof BaSO4precipitates when1.350Lof 0.0550 M BaI2 and1.200 Lof0.0476 M MgSO4(aq)are mixed.

2006-11-28 05:54:26 · 3 answers · asked by Anonymous

I weighed out 0.2538g of pure ascorbic acid (F. Wt = 176.12g). I dissolved with <30mL of deionized water and added about 0.5 mL of diluted HNO3. Then I transfered it to a 50mL volumetric and diluted to volume. What's the concentration?

2006-11-28 05:49:10 · 3 answers · asked by slicksingh2k 2

How many grams of Al2(SO4)3 are needed to prepare 250.0 mL of a 0.400 M Al2(SO4)3 solution?

Details please...I havent learned this and my teacher just threw it in my face. Thanks!!

2006-11-28 05:47:32 · 5 answers · asked by Anonymous

Thanks you guys once again!!

2006-11-28 05:43:35 · 2 answers · asked by Anonymous

What volume (mL) of 0.139 M LiOH contains 25.0 g of LiOH ?

2006-11-28 05:30:54 · 3 answers · asked by nietzsche 1

Calculate the number of moles of Na+ ions in 1.60 L of 0.330 M Na2SO4.

2006-11-28 05:30:14 · 3 answers · asked by nietzsche 1

This is part of a assignment for chemistry class I could really use some help!

2006-11-28 05:27:15 · 3 answers · asked by kittycats_legacy 1

2006-11-28 05:20:01 · 2 answers · asked by chemistryppl 2

It doesnt dissolve in water...I need some examples. Thanks!!

2006-11-28 05:13:12 · 5 answers · asked by Anonymous

1. How many grams of sucrose, C12H22O11, must you use to make 150.00 mL of a 1.00 molar solution in Water?
2. What is the osmolarity of a 1.00 M solution of sucrose?
3. You have been given a 0.9% (m/v) NaCl solution. Answer the following:
a. What is the molarity of the above solution?
b. What is the osmolarity of the above solution?
c. Wht is the osmotic pressure of the NaCl solution in mmHg?
4. Given a 0.703 M NaCl solution that has a density of 1.0268 g/mL, calculate the following?
a. The % NaCl (m/m).
b. The molar concentration of NaCl.
5. Given the cryosopic constant of camphor is 37.8 degrees C/m. The symbole m is the molar concentration.
a. 0.1000 g of sulfur was dissolved in 10.000g of camphor. The freezing point of this solution dropped from 178.8 to 177.3 C. What is the molecular weight of sulfur?
b. Based on the answer above, how many sulfur atoms are in a sulfur molecule.

2006-11-28 05:00:52 · 3 answers · asked by S Denise J 2

1- If sodium is not replaced by anything
2- If it is replaced by H+ through ion exchange process

2006-11-28 04:53:14 · 3 answers · asked by aeugas z 1

A) proton
B) electron
C) hydronium ion
D) hydrogen ion
E) hydride ion

2006-11-28 04:36:40 · 7 answers · asked by Donna G 1

1)H2O
NaCO3
NaOH
NaCI

2) Which of the follwing is an acid?
NaCI
KCI
LiCI
HCI

3)What happens when an acid is neutralized with a base?
a precipitate forms
a colour change occurs
a salt is formed
a bright light is seen

Again thanks for any help

2006-11-28 04:34:46 · 3 answers · asked by margarittanosalt 2

A 50. mg sample of iodine -131 was placed in a container 32.4 days ago. If its half-life is 8.1 days, how many milligrams of iodine131 are now present?

2006-11-28 04:31:26 · 6 answers · asked by Donna G 1

2006-11-28 04:25:00 · 1 answers · asked by angel c 1

How many half-lives are needed for a 400.0 ng sample of a radioactive isotope to decay to 12.5ng?

2006-11-28 04:19:15 · 3 answers · asked by carmond70 1

If 14.8 mL of 0.100 M NaOH sol are needed to react with 25.0 mL of an unknown HCl sol, what is the molar concentration of the HCI solution?

2006-11-28 04:04:25 · 2 answers · asked by carmond70 1

What is the pH of a solution that has [H3O^+]=6.0*10^-3 M?

2006-11-28 03:59:04 · 2 answers · asked by carmond70 1

2006-11-28 03:58:10 · 4 answers · asked by paul g 1

Potassium perchlorate, KCIO4, decomposes on heating to form potassium chloride and elemental oxygen.

a. Write a balanced molecular equation for the thermal decomposition of potassium perchlorate.


Using a setup like this experiment, the following data were collected:

weight of sample before heating= 1.2460 g
weight of sample after heating= 0.9265 g
volume of water displaced= 258 mL
atmospheric pressure= 748.9 torr
water temperature= 26.0 degrees Celsius

b. What is the percent KCIO4 in the sample being heated?

c. What volume would this sample of oxygen occupy if collected at standard temperature and pressure?

d. What is the molar volume at STP of O2 according to these data?

2006-11-28 03:54:12 · 3 answers · asked by Me 2

Does any one have any tips how to remember the valencies pls?

2006-11-28 03:53:44 · 2 answers · asked by Anonymous

it is good to know when the power is out.

2006-11-28 03:43:08 · 10 answers · asked by jeeccentricx2 5

2006-11-28 03:08:56 · 19 answers · asked by blingding 5

If 49g of H2SO4 is dissolved and then neutralised by some NaOH producing 63g of Na2SO4 how do I work out what the yield of Na2SO4 is?

do I need to work out the mass and then the moles of each substance or is there a simpler way of working it out?

Thanks

2006-11-28 02:19:20 · 4 answers · asked by Anonymous

Which is correct,

1. the bond distance increases as you increase the bond order.

2. The bond distance decreases as you increase the bond order.

3. The bond distance remains the same as you increase the bond order.

4. The bond distance is not directly related to the bond order.

2006-11-28 02:14:44 · 2 answers · asked by rnjes21 2

she said we could chose any topic under science. what do u think is a good topic?

2006-11-28 02:10:03 · 5 answers · asked by NikoleUniQue 2