<p>You can just copy and paste the list (:</p>
<p>I thought it wasn’t a buffer in number one since buffers are made of a weak acid or base plus a salt and HCl is a strong acid.</p>
<p>That’s what i was confused as to also I thought the NH3 all reacted and there isn’t any left…</p>
<p>im not sure whether or not it was a buffer but a buffer can also be just when you add one solution to another and the pH of that solution does not change (drastically).</p>
<p>I’m pretty sure the rate in number 6 is positive because you can’t get a negative molarity.</p>
<p>But it must also contain a weak/conjugate, no?</p>
<p>Here is all I have so far:
1
a
b
i)
ii)
c
i)
ii)
d
i) Yes
ii)</p>
<p>2
a
i)
ii)
iii)
iv) NahCO3
b 0.00376moles
c</p>
<p>3
a
b
c
d
e 1.23
f
i) 1.86
ii) 300
gFuel cells based on butane release Carbon Dioxide gas which is detrimental to the Earth, potentially aggravate global warming, etc. Also, butane cells require the use of Butane, which is a highly flammable, combustible hydrocarbon. It can thus be dangerous to use, etc. Hydrogen cell simply gives off water and is much safer and environmentally friendly. </p>
<p>4
a
i)
ii) 100 mL
b
i) Cu + 2Ag+ –> Cu2+ + Ag
ii) Cl
c
i)
ii) Silver flakes start to attach to copper wire</p>
<p>5
a
b No
c
d
e Red-Ox
f Positive
g False</p>
<p>6
a Equal
bAverage kinetic energy of molecules, and therefore average speed of the gas molecules, is directly related to absolute temperature. When you increase temperature, you are increasing average kinetic energy and average speed. More gas molecules are moving at faster speeds in random chaotic motion and their collisions are elastic. The total force in the container thus increases while the area is the same. Thus, the pressure increases.
c
i) Zero
ii) Rate = k
iii) .0000040 M/sec = k
d .8 atm</p>
<p>Uhh someone posted earlier that you put the HBr into the beaker and then the graduated cylinder.
Why would you do that? The cylinder is more accurate than the beaker.
I wrote to measure stuff out with the cylinder and then transfer both into the beaker.</p>
<p>1
a 0.100M
b
i)
ii)
c
i)
ii)
d
i) Yes
ii)
2
a 18.75mL
i)
ii)
iii)
iv) NahCO3
b 0.00376moles
c I think 40.6%
3
a -571.6KJ
b -1417 KJ
c
d 2H2 + O2 2H2O
e 1.23
f
i) 1.86
ii) 300
g Cells based off of hydrocarbons release CO2, which is obviously bad for the atmosphere (causes increase in greenhouse gases and warming of atmosphere) while cells based off of hydrogen release H2O (obviously more environmentally friendly).
4
a
i)
ii) 100 mL
b
i)
ii) Cl
c
i)
ii) Silver flakes start to attach to copper wire
5
a
b No
c
d
e Red-Ox
f Positive
g False
6
a Equal
b Fuel cells based on butane release Carbon Dioxide gas which is detrimental to the Earth, potentially aggravate global warming, etc. Also, butane cells require the use of Butane, which is a highly flammable, combustible hydrocarbon. It can thus be dangerous to use, etc. Hydrogen cell simply gives off water and is much safer and environmentally friendly.
Higher temp means more kinetic energy. When particles have more kinetic energy, there are more collisions between the particles and with the walls of the container, which causes more pressure. And then I put that by the ideal gas law equation PV = nRT (which explains kinetic molecular theory), raising the temp is sure to raise the pressure. You can see this by plugging in numbers.
c
i) Zero
ii) Rate = k
iii) .0000040 M/sec = k</p>
<p>d .8 atm</p>
<p>I a asks for pH not molarity.</p>
<p>Take this: Fuel cells based on butane release Carbon Dioxide gas which is detrimental to the Earth, potentially aggravate global warming, etc. Also, butane cells require the use of Butane, which is a highly flammable, combustible hydrocarbon. It can thus be dangerous to use, etc. Hydrogen cell simply gives off water and is much safer and environmentally friendly.</p>
<p>out of 6 b</p>
<p>& add this to 4 b Cu + 2Ag+ –> Cu2+ + Ag (:</p>
<p>& 5.55 E -10 for 1)c)i)</p>
<p>I thought that it wasn’t a buffer, because although it had a weak base and it’s conjugate acid (NH3 and NH4+), the relatively large amount of HCL added threw it off.</p>
<p>For the percentage of silver, isn’t it .405 g Ag (.00375 mol * 107.87 g/mol) divided by the alloy mass (.6489 g) to get 62.4% silver?</p>
<p>1) d. (i) is not a buffer because all of the hcl reacts with ALL of the NH3 to produce NH4. Thus, only NH4 is there, no conjugate base, and thus it is not a buffer. and i think [NH4] for (ii) would be 0.200 M.</p>
<p>I also thought a buffer could not be made with a strong acid…but if the pH didn’t change more than like + or - 0.5 then it would appear that it behaves as a buffer solution</p>
<p>Firered, shouldn’t the concentration be .0667 M? There’s 75 mL of solution in total, so the molarities of .100 NH4+ from the salt and .100 made from the NH3 + HCl reaction are not additive. Each molarity should be a third of their original number.</p>
<p>I agree with firered entirely, that was my entire thought process, how did you calculate [NH4]?</p>
<p>@HBSoph, you are completely correct I believe. Oh well, I didnt get this question right anyways.</p>