• ### Does hot move to cold or cold move to hot?

Best answer: Hot moves to cold
Best answer: Hot moves to cold
7 answers · 2 weeks ago
• ### What is a reasonable approximation of salt concentration of distilled water?

4 answers · 2 weeks ago
• ### True or False In a sample of hydrogen gas at 25 °C, all hydrogen molecules will be moving with the same velocity.?

5 answers · 2 weeks ago
• ### Need help with this question.?

Xenon can be made to react with fluorine gas to produce xenon tetrafluoride. If 16.30g of xenon is used, what mass of fluorine, in grams, is needed to react completely with the xenon?
Xenon can be made to react with fluorine gas to produce xenon tetrafluoride. If 16.30g of xenon is used, what mass of fluorine, in grams, is needed to react completely with the xenon?
4 answers · 2 weeks ago
• ### Which is better Propane or Chorcoal?

4 answers · 2 weeks ago
• ### A sample of a liquid isn't boiling, what are 2 ways to make the liquid boil?

Best answer: raise the temperature or lower its pressure
Best answer: raise the temperature or lower its pressure
4 answers · 2 weeks ago
• ### How do we recognize our assumption is wrong when we solve acid-dissociation constant problem?

Best answer: I have been taught that when the dissociation is less than 5% ( the 5% rule) it is OK to take [HA] = original concentration of the acid. X will always be smaller than [HA] , because dissociation is weak. In this case X must be less than 5% of 0.1M or 0.005M. Using your method , and dividing by 0.1 , you must have... show more
Best answer: I have been taught that when the dissociation is less than 5% ( the 5% rule) it is OK to take [HA] = original concentration of the acid. X will always be smaller than [HA] , because dissociation is weak. In this case X must be less than 5% of 0.1M or 0.005M.
Using your method , and dividing by 0.1 , you must have found
1*10^-2 = [x] ² / 0.1
[X]² = (1*10^-2) *0.1
[X]² = 1*10^-3
[X] = 0.032M which is 32% dissociation - which is far too high to ignore X in the denominator . You have to divide by (0.1-X) .
But if Ka = 1*10^-4
1*10^-4 = X² / 0.1
x² = 1*10^-5
x = 3.2*10^-3 M = 0.0032M
and % dissociation = 0.0032/0.1*100 = 3.2% and you can definitely use 0.1 in the denominator
As a rule of thumb , if Ka is smaller than 1*10^-4 (as shown above) then you can use this rule. In your case Ka = 1.0*10^-2 , (which is > 1*10^-4) so you clearly cannot use the rule , and you have to divide by (0.1 - X) and you end up with a quadratic equation. In my opinion , marking your answer incorrect was properly done. Sorry.
4 answers · 2 weeks ago
• ### True or False Oxygen molecules at 25 °C will be moving faster than oxygen molecules at 0 °C.?

3 answers · 2 weeks ago
• ### Gas Law, Density & Molarity Question?

Best answer: One way is to use the combined gas equation

P1 * V1 / T1 = P2 * V2 / T2. Substituting gives you 175.6 L

Or, use the density to calculate the mass of gas, 274.5 g

mass = density * volume

274.5 g = PM/RT * volume

solve for the volume, 175.6 L
Best answer: One way is to use the combined gas equation

P1 * V1 / T1 = P2 * V2 / T2. Substituting gives you 175.6 L

Or, use the density to calculate the mass of gas, 274.5 g

mass = density * volume

274.5 g = PM/RT * volume

solve for the volume, 175.6 L
4 answers · 2 weeks ago
• ### True or False: In a combustion reaction, one substance breaks down into two or more substances?

5 answers · 2 weeks ago
• ### Can atoms remember where they've been?

6 answers · 2 weeks ago
• ### Are all scientists asexual?

5 answers · 2 weeks ago
• ### How can gas particles go back into a liquid?

4 answers · 3 weeks ago
• ### What is it like to die in Iowa?

Best answer: Very similar to dying to Nebraska but nothing like dying in the Ukraine.
Best answer: Very similar to dying to Nebraska but nothing like dying in the Ukraine.
7 answers · 3 weeks ago
• ### What causes gas odors coming from a stove?

8 answers · 3 weeks ago
• ### If 90.5 moles of an ideal gas is at 1.77 atm at 34.80 °C, what is the volume of the gas?

3 answers · 3 weeks ago
• ### I need CO for a world changing invention but I don't know where to get it and using other chemical reactions to produce is to impure.?

5 answers · 3 weeks ago
• ### I would like to know how to triple freeze water to cure cancer?

6 answers · 3 weeks ago
• ### Why use dm water in lead acid battery...?

5 answers · 3 weeks ago