Chemistry - November 2007

1.907g of M contains 2.87 x 10^22 atoms of M.

M is a Group 0 element. Caculate the relative atomic mass of M, given that the Avogadro constant = 6.02 x 10^23 mol^ -1

I'm not sure how to tackle this as I haven't done one before - could you please provide the steps in the calculation?

Thanks

2007-11-21 05:26:50 · 4 answers · asked by Ella B 2

a) Au3+(aq) + Ag(s) →

b) Na+(aq) + Zn(s) →

c) 2Ag+(aq) + Cu(s) →

2007-11-21 05:23:22 · 1 answers · asked by unique_fantasy 1

For statements a) through d) use the reaction:
SiCl4(l) + 2Mg(s) --> 2MgCl2(s) + Si(s)
a) Mg is the oxidizing agent
b) SiCl4 is the oxidizing agent
c) Mg is oxidized
d) SiCl4 (or Si in SiCl4) is oxidized
e) Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g) is a redox reaction
f) 2CuCl(aq) --> CuCl2(aq) + Cu(s) is a redox reaction

2007-11-21 05:16:41 · 5 answers · asked by unique_fantasy 1

a) H2O2

b) K

c) Fe

d) Cu

e) C

2007-11-21 05:14:42 · 5 answers · asked by unique_fantasy 1

2007-11-21 05:03:01 · 6 answers · asked by Anonymous

2007-11-21 04:54:59 · 8 answers · asked by Anonymous

Here's the compound

NO2 C6H4 CHOH CHNHCOCHCL2 CH2OH

It looks like 5 different ones combined. How do I find the center?

2007-11-21 04:46:10 · 2 answers · asked by kay l 2

2007-11-21 04:38:29 · 2 answers · asked by Maureen 1

a) Au3+(aq) + Ag(s) →

b) Na+(aq) + Zn(s) →

c) 2Al3+(aq) + 3Zn(s) →

2007-11-21 04:17:59 · 3 answers · asked by FiniteOxide 5

2007-11-21 03:59:40 · 1 answers · asked by Anonymous

2007-11-21 03:52:54 · 1 answers · asked by Anonymous

Place the following in order of increasing magnitude of lattice energy.

MgO
LiI
CaS

A) CaS < MgO < LiI
B) LiI < CaS < MgO
C) MgO < LiI < CaS
D) MgO < CaS < LiI
E) LiI < MgO < CaS

2007-11-21 03:45:05 · 1 answers · asked by Jay H 1

And for bonus points - What does HLB values mean when refering to Sugar Esters?

2007-11-21 03:38:46 · 1 answers · asked by Anonymous

2007-11-21 02:17:17 · 4 answers · asked by xxcolombiang12xx 1

I dont know what to do with this problem after multiplying 2.19 amperes by the time in seconds. Then afterwards dividing it by the constant 96485 coulombs and left with moles of electrons: how do i get the mass they are asking me for?

1) Gold can be deposited by electrolysis. What mass of gold in g will be deposited by the electroplating of Au(NO3)3 using 2.19 amperes for 3.03 hr?

2007-11-21 01:39:49 · 1 answers · asked by Anonymous

2007-11-21 01:36:49 · 3 answers · asked by Butterfly Girl 1

When lead is put in copper sulfate, what are the 2 equations? thanks!

Fastest CORRECT answer (with a small explanation please) will be chosen as the best.

2007-11-21 00:12:09 · 1 answers · asked by onlineworld 1

2007-11-20 22:03:54 · 1 answers · asked by Anonymous

2007-11-20 17:48:04 · 4 answers · asked by biffbifford@sbcglobal.net 1

Novelty devices for predicting rain contain cobalt(II) chloride and are based on the following equilibrium.
CoCl2(s) + 6 H2O(g)↔ CoCl2·6 H2O(s)
Purple Pink

What color will such an indicator be if rain is imminent?
pink
purple
not enough information to decide

2007-11-20 17:38:25 · 1 answers · asked by Anonymous

2007-11-20 17:16:07 · 11 answers · asked by Jaz G 1

Using data from #39, determine the molarity of O2 in an aqueous solution at equilibrium with air at normal atmospheric pressure. The volume percent of O2 in air is 20.95%.

Data in #39: Under an O2(g) pressure of 1 atm, 28.31 mL of O2 dissolves in 1 L H2O at 25 C.

2007-11-20 17:04:48 · 1 answers · asked by Ariel 2

i dont understand how this works.. if someone can show me how, and also why it works..that would be awesome.

1. CO2
2. CO
3. SO2
4. SO3
5. N2O
6. NO
7. N2O3
8. NO2
9. N2O4
10. N2O5
11. PCl3 (chlorine)
12. PCl5 (chlorine)
13. NH3
14. SCl6 (chlorine)
15. P2O5
16. CCl4 (chlorine)
17. SiO2
18. CS2
19. OF2
20. PBr2

2007-11-20 16:28:57 · 1 answers · asked by Anonymous

2007-11-20 16:11:36 · 1 answers · asked by honey 3

First, Calculate the wavelength of the light that corresponds to the transition of the electron from the n=4 to n=2 state of the hydrogen atom. Is the light absorbed or emitted??? (1.0967 for transition)


What is the energy of the single electron in a hydrogen atom when it is in the n=4 state??? Is it (-2.178 x 10^ -18 / 16)
Not sure how, though!!!!Explain, please!!!!

Which of the following could be the quantum numbers (n l m(subscript l) m(subscript s) for the valence electron in a potassium atom in its ground state!!!!!! Explain, please!!!

2007-11-20 16:04:45 · 1 answers · asked by Doc. Ock 3

2007-11-20 16:04:30 · 1 answers · asked by Anonymous

The human eye is a complex sensing device for visible light. The optic nerve needs a minimum of 2.0*10^-17 J of energy to trigger a series of impulses that eventually reach the brain.

(a) How many photons of red light (660 nm) are needed?

(b) How many photons of blue light (475 nm) are needed?

2007-11-20 16:00:08 · 1 answers · asked by Ruby Winter 2

What color are actual "neon" lights?

2007-11-20 15:54:00 · 2 answers · asked by Kevin 1

How do you write the chemical equation for the combustion of ibuprofen (C13H18O2). Is this reaction balanced? Justify your answer.


Why is NO2 a balanced equation?
Is this reaction endothermic?

How do you write a chemical equation for the reaction in which sodium and water make hydrogen gas and sodium hydroxide (NaOH). Is this reaction balanced?


How can you write out a chemical equation for the reaction in which nitrogen triiodide makes nitrogen gas and solid iodine (I2). Is this reaction balanced?

Write a chemical equation for the combustion of ethyl alcohol (C2H6O). Is this reaction balanced?


Write a chemical equation for the combustion of ibuprofen (C13H18O2). Is this reaction balanced?

2007-11-20 15:52:05 · 2 answers · asked by Jaz 'ma' Taz 2

i Think it Has To Do With Electrons?

2007-11-20 15:48:59 · 1 answers · asked by #20babiigurl 1