Chemistry - April 2007

2007-04-22 16:49:43 · 3 answers · asked by ganesh K 1

Does anyone know what is the thing that drops into the liquid and seperate the oil, into a yellow solid in the bottom?
Can we buy it publicly?

2007-04-22 16:31:11 · 4 answers · asked by 56984 2

2007-04-22 16:28:48 · 4 answers · asked by Steven R 2

2007-04-22 16:06:21 · 1 answers · asked by mimi 1

2007-04-22 15:52:26 · 3 answers · asked by hope 1

2H2 (g) + O2 (g) ---> 2H2O (g)

N2 (g) + O2(g) --> 2NO (g)

AgNO3 (aq) + NaCl (aq) ---> AgCl (s) + NaNO3 (aq)

2007-04-22 15:30:09 · 1 answers · asked by Paulllll C 3

2007-04-22 15:18:15 · 5 answers · asked by harry 1

I AM COMPLETELY LOST!!!
I dont even understand what a logarithm is and I am doing HARD equations using them in m chem class.
I dont understand how to answer the following problems...If someone could please EXPLAIN THE STEPS to getting the answers that would be WONDERFUL. THANK YOU!!!

Find the pH if the concentration of [H3O] is 0.25M
pH= -log[H3O]
pH= -log[0.25]
pH= 0.60
???

Find [H3O] if pH is 2.7
[H3O]= 10 to the -pH
[H3O]= 10 to the 27th power
[H3O]= 0.200
???


Find the [H] of a pH of 6.8
1.58 x 10 to the negative 7 power
???


Find the [OH] if the [H3O] is 0.000035M
2.86 x 10 to the negative 10 M
???
SOMEBODY PLEASE PLEASE EXPLAIN!!!! PLEASE!!!!!!

2007-04-22 15:17:17 · 4 answers · asked by NoNameNoFace 2

2007-04-22 15:03:34 · 2 answers · asked by Jackie S 1

what is the equivalent of 8 mL of water in terms of moles?

thanks so much!

2007-04-22 15:02:51 · 2 answers · asked by bluenecklace 2

H2SO4, HI, HF, H3PO4, HNO3
that are strong acids and no weak acids?

1. H2SO4, HNO3
2. HI, HF, HNO3
3. H2SO4, H3PO4, HNO3
4. H2SO4, HI, HNO3
5. another one or another combination

2007-04-22 15:02:31 · 1 answers · asked by Jackie S 1

2007-04-22 15:01:59 · 2 answers · asked by Jackie S 1

COMPLETE and BALANCE the following

2007-04-22 14:57:08 · 2 answers · asked by Tytus 1

im studying for a lab exam for chemistry, and on our review we have a question i cannot figure out.

it says

a 7.302 sample of CuCl2 yields 100% of the copper in the sample. how many moles of copper should be obtained from this sample.
(1 g-atom of Cu = 63.55 Cu; 1 g atom of CL = 35.45g Cl)

im looking for someone to explain the way to go about to get the answer, so i can do it on the exam.

thanks allooot. i hate chemistry, im so bad at it.

2007-04-22 14:56:49 · 1 answers · asked by ilikegcalot 1

2007-04-22 14:56:41 · 3 answers · asked by Anonymous

1. can act either as a base or an acid.
2. cannot act as an acid nor a base since it
is neutral.
3. can act as a base.
4. can act as an acid

2007-04-22 14:52:34 · 1 answers · asked by Anonymous

1. None of these
2. 1.4 x 10-7 M
3. 0.50 M
4. 5.0 M
5. 2:0 x 10-14 M

2007-04-22 14:45:25 · 1 answers · asked by Anonymous

15.3g NaNO3 dissolved in 256g Water in a coffee-cup calorimeter. Temperature of water falls from 25.00 degrees C to 21.56 degrees C. What is the enthalpy change when one mol sodium nitrate is dissolved in water. Specfic Heat capacity of water = 4.184J/g*k

Please explain thanks!

2007-04-22 14:45:18 · 1 answers · asked by burgler09 5

Reaction mixtures of the following systems are prepared and allowed to come to equilibrium. Which (if any) of the systems will shift their equilibrium towards more products when the total pressure in the container is increased by decreasing the volume?
A) 2C(s) + O2(g) ⇔ 2CO(g)
B) CO2(g) + H2(g) ⇔ H2O(l) + CO(g)
C) 2CO(g) + O2(g) ⇔ 2CO2(g)
D) 2NO(g) ⇔ N2(g) + O2(g)
E) N2O4(g) ⇔ 2NO2(g)
F) Ni(s) + 4CO(g) ⇔ Ni(CO)4(g)

2007-04-22 14:44:23 · 2 answers · asked by Mixed Asian 5

1. a hydronium ion.
2. a hydrate.
3. an electron.
4. a proton.

2007-04-22 14:37:55 · 6 answers · asked by Anonymous

A 100mL sample of 0.200 M aqueous hydrochloric acid is added to 100mL of 0.200 M aqueous ammonia in a calorimeter whose heat capacity is zero. The following reaction occurs when the two solutions are mixed. [Assume that the density of the resulting solution is that of pure water].
HCl (aq) + NH3 --> NH4Cl (aq)
The temperature increase is 2.34 Celsius. Calculate delta H per mole of HCl and NH3 reacted.

2007-04-22 14:26:16 · 1 answers · asked by ahsuog 1

A 100mL sample of 0.200 M aqueous hydrochloric acid is added to 100mL of 0.200 M aqueous ammonia in a calorimeter whose heat capacity is zero. The following reaction occurs when the two solutions are mixed. [Assume that the density of the resulting solution is that of pure water].
HCl (aq) + NH3 --> NH4Cl (aq)
The temperature increase is 2.34 Celsius. Calculate delta H per mole of HCl and NH3 reacted.

2007-04-22 14:25:10 · 2 answers · asked by ahsuog 1

At Standard Pressure, which element at 25°C could undergo a change of phase when the temperature is decreased?

aluminum
chlorine
silicon
sulfur

As each successive element in Group 15 of the Periodic Table is considered in order of increasing atomic number, the atomic radius

decreases
increases
remains the same

Which element in Group 15 (VA) has the most metallic character?

N
P
As
Bi

Which statement correctly describes diamond and graphite, which are different forms of solid carbon?

They differ in their molecular structure, only.
They differ in their properties, only.
They differ in their molecular structure and properties.
They do not differ in their molecular structure or properties.

2007-04-22 13:55:46 · 1 answers · asked by Celia 4

How do u find the enthalpy of decomposition of NaHCO3 from experimental data? Here's what I did:

1) Reacted NaHCO3 with HCl
2) Then, I reacted Na2Co3 with HCl

Mass of NaHCO3 used = 0.00352 kg
Mass of Na2CO3 used = 0.0028 kg
delta T for (NaHCO3-HCl) reaction = -7.5 K
delta T for (Na2CO3-HCl) reaction = 5.5 K
Specific heat capacity of water = 4200 JKg^-1K^-1

2007-04-22 13:47:21 · 1 answers · asked by Anonymous

Can someone help me calculate the mole Fraction of 3.21 g NaOH in 0.752 L H2O?

2007-04-22 13:30:57 · 3 answers · asked by Britt 2

Barium chloride + Sodium carbonate
a.) name of precipate = Barium carbonate
b.) ion equation for precipitate formed = BaCO3
c.) ion equation for original solutions = BaCl2
d.) ion equation for new solution.... okay this is where i get stuck. the answer is: NaCl, but I don't get how they got that from all of the above... are they putting Sodium & the chloride from the original solutions together??

and how would you do this next one?

Barium chloride + Magnesium sulfate
a.) write name of precipitate formed.
b.) write ion equation for the precipitate formed.
c.) write ion equation forthe original solutions.
d.) write ion equation forthe new solution.
e.) write the name of the new solution.

thanks for all your help. i really don't get this stuff.

2007-04-22 13:17:12 · 2 answers · asked by ok buddy 2

Which of the following are true statements for the given compound ?



a) HBr : A Bronsted acid and a Lewis acid

b) HCN : A Lewis acid, but not a Bronsted acid

c) CH3COOH : A Bronsted acid, but not a Lewis acid

d) Ni 2+(aq) : A Bronsted acid, but not a Lewis acid

e) C6H6 : Both a Bronsted acid and a Lewis acid

2007-04-22 12:17:58 · 2 answers · asked by tobeever 1

1) Which pairs of elements WONT form ionic compounds? CHOOSE:
(A) Sulfur & Oxygen (B) Sodium & calcuim
(C) Sodium & Sulfur (D) Oxygen & Chlorine

2)Which substances are NOT Most likely ionic?
(A) H2O (B) Na2O (C) CO2 (D) CaS (E) NH3 (F) SO2

3) CHOOSE the 2nd term that completes the relationship:
(A) Cow: Horse ; Ionic Bond:_ (Anion, Cation, chemical bond, Covalent Bond)

(B)Cl: Cl - ; Mg:_ ( (these are charges, not sunscript)Mg2+, Mg2-, Al3+, Mn)

2007-04-22 12:01:34 · 4 answers · asked by truckin_90 2

2007-04-22 11:57:04 · 4 answers · asked by CRYSTAL L21 3

2007-04-22 11:36:18 · 6 answers · asked by jk_haha_04 1