Chemistry - January 2007

2007-01-18 10:58:31 · 16 answers · asked by Anonymous

2007-01-18 10:54:20 · 4 answers · asked by euqi 1

Which of the following is necessary to calculate the atomic mass of an element?
a.

the atomic mass of carbon-12
b.

the atomic number of the element
c.

the relative masses of the element’s protons and neutrons
d.

the masses of each isotope of the element

2007-01-18 10:53:04 · 4 answers · asked by Anonymous

how many mole of oxygen are required to produce 6 moles of zinc oxide?

2007-01-18 10:51:47 · 2 answers · asked by chockalaka 1

Which of the following equals one atomic mass unit?
a.

the mass of one electron
b.

the mass of one helium-4 atom
c.

the mass of one carbon-12 atom
d.

one-twelfth the mass of one carbon-12 atom

2007-01-18 10:51:34 · 4 answers · asked by Anonymous

When I read the definitions for molecule and compound they appear almost identical in what they describe. I've been told that there is a difference. What is the difference between the two?

2007-01-18 10:50:21 · 4 answers · asked by Kender_fury 3

a. ethyne
b. 2-butyne

2007-01-18 10:48:09 · 2 answers · asked by Anonymous

Find the limiting reagent and the reactant in excess when 100 mL of 0.2 mol/L Ba(OH)2 react completely with 50 mL of 0.5 mol/L of sulfuric acid. What is the mass of the precipitate.

2007-01-18 10:39:27 · 2 answers · asked by untilyoucamealong04 3

2007-01-18 10:31:35 · 6 answers · asked by youngnlovely991 1

11) C2H2 is made from adding water to CaC2.

CaC2 (s) + 2H2O (l) >>>>C2H2 (g) + Ca (OH)2 (aq)

How many Grams of acetylene are produced by adding water to 5.00 g CaC2?

12) using the same equation, how many moles of CaC2 are needed to react completely w/ 49.0 g H2O?

2007-01-18 10:26:53 · 1 answers · asked by truckin_90 2

and put roman numerals if need be.


1. KOH
2. (NH4)3PO4
3. Pb(SO4)2


that's all. Thank you, I'm just having a hard time on these. :D

2007-01-18 10:18:33 · 2 answers · asked by Lily 1

Physical Or Chemical Property?!

A. It is a white, waxy soild.
B. it burns in air.
C. its melting point is 44.1(degrees)C.
D. it has a density of 1.82 g/cm(cubed)
E. its boiling point is 280.3(degrees)C.

2007-01-18 10:17:52 · 4 answers · asked by Anonymous

A) Its Density is 2.97 g/cm(cubed)
B) It reacts with hydrogen to form a gas.
C) It is a yellow solid.
D) Its melting point is 112(degrees) C.
E) It combines with oxygen.

2007-01-18 10:13:46 · 3 answers · asked by Anonymous

If an aqueous solution has [OH] = 3.0 x 10-11 mol/L, would the solution be:
a. An acidic solution
b. A basic solution
c. A neutral solution
And why?

2007-01-18 10:13:27 · 5 answers · asked by untilyoucamealong04 3

3. The pH of a solution is 5. What is the hydrogen ion concentration as well as the hydroxide ion concentration?

2007-01-18 10:11:41 · 1 answers · asked by untilyoucamealong04 3

This can turn greenhouse gas into fuel (CO is the starting point for Fischer-Tropsch reaction)

2007-01-18 10:09:04 · 4 answers · asked by joker 1

hw question and i'm really stuck.

It also asks .... WHat is the percent of water in the hydrate formed? show work.

Please help. THanks.

2007-01-18 10:07:11 · 2 answers · asked by Kara T 1

and give roman numerals if need be.....

1. Ca(OH)2
2. Pb(NO2)2
3. Ba3(PO4)2
4. Cr2O3
5. NH4Br
6. MgCr207
7. Pb(CO3)2
8. NH4Br

thank you.

2007-01-18 10:03:08 · 3 answers · asked by Lily 1

2007-01-18 10:01:58 · 3 answers · asked by Kimberly B 1

I have a report on tetraflouroethane and i have to find the atomic
number, atomic weight, its symbol, valence number, electron orbit, and which famliy it belongs two

2007-01-18 10:00:36 · 3 answers · asked by soldier4christ_05 1

2007-01-18 10:00:27 · 2 answers · asked by Anonymous

2007-01-18 09:56:45 · 1 answers · asked by Anonymous

For example, I heard of "Stop Entropy" , or "Calculus has it's Limits", "Caution: Hot beakers look exactly like cool beaker", etc....

I'm looking for anything related to Chemistry, calculus, or physics. Thanks!

2007-01-18 09:26:28 · 9 answers · asked by msvietpig 3

2007-01-18 09:18:19 · 7 answers · asked by asdfasdffdas 1

2007-01-18 08:58:45 · 5 answers · asked by Cassy P 1

2007-01-18 08:56:03 · 1 answers · asked by Victor H 1

2007-01-18 08:45:40 · 3 answers · asked by riena c 1

Balance each half-reaction for atoms and charge.
a) Na->Na+
b)Sn4+->Sn2+
c)Fe2+->Fe3+
d)Cl2->Cl-

Also I need help with matching 5 reactions....

Fe+CuSo4->FeSO4+Cu
CaO+H2O->Ca(OH)2
NH4NO3->N2O+H2O
Ca(OH)2+2HCl->CaCl2+2H2O
C+O2->CO2

A) single displacement reaction
B) decomposition reaction
C) double displacement reaction
D) synthesis reaction
E) combustion reaction



Lastly balancing this equation.
CO2+H2->CH4+H2O


Please help me. I know it may seem like a lot but I dont understand them. I'm doing this as an online test and I really need help I've done majority of my test questions but these. Please help!

2007-01-18 08:36:00 · 2 answers · asked by Anonymous

If a drug dose is 280 mg/kg and a patient weighs 220 lbs, what is the correct dose in ounces?
(2.2 lbs = 1 kg, 28 g = 1 oz)

can you show the steps?
thank u in advance

2007-01-18 08:17:08 · 1 answers · asked by Anonymous

Hi, I study at home and I am having a hard time with Chemistry. I need urgent help!! I added three problems that I would be very thankful if anyone helped solving them. THANK YOU VERY MUCH!!


Consider HSO-4 , NH+4 , H2O , SO2-2. Which one or which ones can be classified as Bronsted base?


a) HSO-4 , NH+4 , H2O ,

b) H2O and SO2-2

c) HSO-4 Only

d) NH+4 Only

e) SO2-2 Only



Fix the coefficient of the following reactions, using the oxi-reduction method.


a) P + HNO3 + H2O ---- H3PO4 + NO

b) Hg + HNO3 ----- Hg (NO3)2 + H2O + NO

c)MnO2 + HBr ---- MnBr2 + Br2 + H2O


In the reaction HNO3 + H2S --- H2O + NO + S , the sum of all coefficients after the adjustment will be:

( ) 16
( ) 20
( ) 14
( ) 12
( ) 18

2007-01-18 08:13:54 · 1 answers · asked by jon c. 3