Chemistry - December 2007

2007-12-02 02:41:37 · 1 answers · asked by kiki 1

the Question is ....

___________ elements suck as gold, silver, nickel, and iron are minerals made up of only one atom.

2007-12-02 00:11:42 · 6 answers · asked by Anonymous

earth metal

2007-12-01 23:45:19 · 12 answers · asked by Anonymous

2007-12-01 22:13:35 · 2 answers · asked by Anonymous

500 grams of a radioactive substance is expected to decay exponentially to 125 grams in the course of 20 years.


(a) Write down the half-life, and the rate of decay of the radioactive substance.









(b) Write down the function in time, N(t), where t is in years, representing the exponential decay of the radioactive substance.











(c) How much of the substance is expected to remain after 15, 25, and 40 years, respectively?. How long would it take for the radioactive substance to decay to under 1 gram?.

2007-12-01 20:09:02 · 2 answers · asked by Anonymous

2007-12-01 20:00:05 · 6 answers · asked by Nicolas 2

how does it look like before and after adding?

2007-12-01 19:09:28 · 3 answers · asked by dk 1

2007-12-01 19:04:13 · 11 answers · asked by George T 2

Would like to prepare Cotton and Polyester adjascent fabric (conforming to ISO specification) used in Colour Fastness testing of dyed matetrials for use in our lab. Can anybody enlighten me on the construction particulars for this fabric and physico / chemical properties to be imparted.

2007-12-01 18:55:13 · 1 answers · asked by ramaki u 1

1. For the reaction N2(g) + 3H2(g) = 2NH3(g)

Kp = 5.60×10−3 at 258 degrees C. What is the K for the reaction at this temperature?


2.
For the reaction 2CH4(g) = C2H2(g) + 3H2(g)

K = 0.150 at 1638 degrees C. What is the Kp for the reaction at this temperature?

2007-12-01 18:44:14 · 1 answers · asked by Anonymous

The volume of hydrogen gas at 38 degree C and 763 torr that can be produced by the reaction of 4.33g of zinc with excess sulfuric acid is _________L.

Zn + H2SO4  H2 + ZnSO4

2007-12-01 15:43:10 · 3 answers · asked by missy 1

1.5L of 3M glucose. Using the dilution equation, determine how much of the 5M solution will be used in the 3M solution. I think that it would be 100mL. Am I right?

2007-12-01 15:35:20 · 1 answers · asked by Anonymous

a gas was found to have a density of 1.85g/l at 780 torr and 0degrees C. What is the molar mass of the gas? thanks!

2007-12-01 15:12:01 · 1 answers · asked by Anonymous

enough water to make 2.50L of solution. I have an answer of 0.609M. Correct or not? thanks

2007-12-01 15:00:02 · 2 answers · asked by Anonymous

My brother is smoking something that smells like strong matches...or sulfer.
DOES ANYONE KNOW WHAT IT IS??
help me please.
I need to know what causes this smell
all I know is that he used a lighter to ignite whatever he was smoking/doing.

2007-12-01 14:53:45 · 3 answers · asked by imacoolllama 1

how do i solve this problem?

a sample of gas occupies 2.50 liters at 1.15 atm of pressure. what is its volume in standard atmospheric pressure?

p.s.if we are finding volume then why does it need to be in standard atmospheric PRESSURE?

2007-12-01 14:43:50 · 4 answers · asked by Anonymous

1.018 g of a Freon gas is trapped in a 145 mL container at 760 mmHg and 50.0 ^C

2007-12-01 14:17:04 · 2 answers · asked by Anonymous

2007-12-01 13:45:02 · 1 answers · asked by CorruptiC 2

Put few drop soap liquide in 50 ml solution of calcium chloride
Please give me a formula chemistry and how can made clear color if is cloud solution. Thank you so much.

2007-12-01 13:42:32 · 1 answers · asked by U68Y 2

which is the limiting reactant...say you wre using 25 g of each, which would be limiting and why?

2007-12-01 13:30:16 · 4 answers · asked by Christine B 1

why doesn't heating the water to find the amount of water in the hydrated crystal not suitable for all hydrates

2007-12-01 13:28:56 · 3 answers · asked by JT 1

CH=CH-CH2-CH2-CH2-CH2 + Br -->

CH3-C=O on top of the C and an -H on top of the C too -->

2007-12-01 13:24:19 · 1 answers · asked by I don't know 2

CH3-CH2-NH2
NH2-CH2-CH2-CH2-NH2

2007-12-01 13:18:41 · 1 answers · asked by I don't know 2

2007-12-01 13:09:35 · 2 answers · asked by crazinati91 1

a sample of gas occupies 3.75 liters ar 16.91 lb/sq in and 25 degrees Celsius. at what temperature in fahrenheit will it occupy 4 liters at 1 atm?

my problem is finding one of the variables to solve the equation

i defined my variables here:
volume 1= 3.75 liters
volume 2= 4 liters
Temp1=25 degrees celsius+273= 298 kelvin
Temp2= (this is what we are finding)
pressure1= 1 atm
pressure2= ????? i dont understand how to find the second pressure

if someone can please show me how to find that second pressure variable that would be so helpful

also do i have to convert the 16.91 lb/sq in for the volume?

2007-12-01 13:09:21 · 2 answers · asked by Anonymous

how much is 60g distilled water converted in mL?

2007-12-01 13:06:01 · 4 answers · asked by RabbityLi 1

2007-12-01 13:01:06 · 2 answers · asked by semi_sonic18 1

Liquefied petroleum gas (LPG) contains gas. Can we use propane gas as a substitute for methane gas? why?

2007-12-01 12:59:24 · 2 answers · asked by semi_sonic18 1

thanks in advance

2007-12-01 12:59:12 · 3 answers · asked by Tony D. 2

Classify the following compound as a primary secondary or tertiary alcohol.

HO-C(CH2CH3)2CH2CH2CH2Br

2007-12-01 12:48:58 · 3 answers · asked by mike m 1