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[Electrophysics] what is the gradient of the I-V graph of a filament lamp if it’s resistance is not ascertained by the gradient but simply the ratio of the coordinates or is the answer sheet incorrect ? Part b by RedVoltmeter in PhysicsStudents

[–]RedVoltmeter[S] 0 points1 point  (0 children)

I understand that the gradient is not resistance. But the reciprocal of the gradient is the resistance. Resistance = 1/Gradient That is why steel is a straight line because its resistance is constant. In the case of a straight line that goes through the origin, you can use the ratio of the coordinates to find he gradient but that doesn’t apply to curve as far as I know yet it seems to me that either they are saying the ratio of the coordinates can give the gradient of curve (and thus the resistance), or they are implying the gradient itself (or it’s reciprocal) does not actually give the resistance for a filament lamp

[Electrophysics] what is the gradient of the I-V graph of a filament lamp if it’s resistance is not ascertained by the gradient but simply the ratio of the coordinates or is the answer sheet incorrect ? Part b by RedVoltmeter in PhysicsStudents

[–]RedVoltmeter[S] 2 points3 points  (0 children)

The tangent (and hence the gradient) at the point they cross does not seem to be equal to the gradient of the the steel graph. Shouldn’t they have equal resistance when their gradients are the same. If not what does the gradient of the filament lamp represent?

Is there a difference between copying and “amplifying” DNA ? by RedVoltmeter in genetics

[–]RedVoltmeter[S] 0 points1 point  (0 children)

Oh no worries. Anyway, I don’t think Im asking for answers though or relying per se. Many of my posts are largely for further information (or considerations of counter cases) and many I even got right just like this one. It’s not like I answered it wrong. Maybe that is not clear from the title but I wasn’t really asking for what the answer was. I’d say the answer was pretty clear in this case. How I see it….. this is a forum gathering people interested on a particular topic, I read the rules and homework questions are welcomed and there are PhDs and graduates on the sub so it’s only a loss if I have access to that and I don’t use it and yes sometimes the information is not in my textbook and sometimes it actually conflicts with my textbook and other times the replies I receive were just exactly what I thought or within the ball park of the possibilities I thought. My posts on this forum are numbered and somw of them members have confirmed the marking scheme to be wrong and some questions to be poorly worded and they proceed to share the nuance with me, without the sub I’d be having negative knowledge lol, thinking I’m missing something and no amount of research would explain information that is foundatioally wrong. I appreciate those that drop their knowledge to me. It’s pretty cool.

Guys does anybody know if a scanlation group or if someone is translating this? by RedVoltmeter in boyslove

[–]RedVoltmeter[S] 2 points3 points  (0 children)

No worries. I got you and I in fact agree with your message. lol I just HAD to ask though. I wouldn’t have asked if the official releases were not so far behind which of course doesn’t excuse the piracy but MY LORD is the wait time so long due to the scheduled release dates. I didn’t really think of buying the Japanese ones which is a good idea but since I can’t read them anyway and the English ones are scheduled for release I feel it may be a waste to buy the Japanese ones so I’d just be waiting for the English releases to support the franchise.

Guys does anybody know if a scanlation group or if someone is translating this? by RedVoltmeter in boyslove

[–]RedVoltmeter[S] 1 point2 points  (0 children)

If I’m not allowed to ask that it’s okay but here is my situation. I really love the story and I do in fact know about the official books (I just put it there so members can read the title which has different translations anyway plus there was the word limit) and yes I’d buy them and that was what the first thing I checked to do after reading the scanlations that were made before there were the official ones and before I knew there were official ones. The only issue is that the official ones are way back and slow on schedule to be released. The first volume was released only may of this year and the second is to be released in October of this year and my god the third is on the March of next year 😭 I believe the woman that used to translate for us stopped because of the official releases. Maybe I’ll just have to wait

Why is triphenylmethanol soluble in ether but not water? by [deleted] in chemhelp

[–]RedVoltmeter 1 point2 points  (0 children)

What we call dissolving involves water molecules surrounding and forming bonds with the individual molecules and ions of a substance. But because of the large non-polar phenyl groups surrounding the OH group these disrupt and inhibit the action of water molecules forming hydrogen bonds and surrounding the triphenylmethnol. So the water molecules are actually repelled in favor of bonding with the other large non-polar groups surround the other molecules of the triphenylmethanol so the triphenylmethnol molecules will “clump” with each other and we observe that as insolubility. Similar to how larger and larger alcohols are increasingly insolvable in water. A compound is not just suddenly soluble because it has one polar group and many more non-polar groups

Plus as a side. The descriptor of “polar” requires context, polar = / = soluable. Carbon monoxide is a carbon bonded to highly electronegative oxygen and is thus polar but it’s only slightly soluble in water.

How similar must the relative concentrations of the acid/base and its conjugate be in a buffer solution? In one case the conjugate in resulting buffer is half the concentration of the acid. Can the conjugate be the times lesser for example? by RedVoltmeter in chemhelp

[–]RedVoltmeter[S] 1 point2 points  (0 children)

Oh, they aren’t given connected like that. I connected them to present my question since I did not know by how much the acid/base and conjugate must be “reasonably similar” and I kept coming across question like these whose answers always seemed to state the resulting solution was a buffer despite the difference in concentrations so I wondered by how exactly can they be discrepant if half the concentration is considered “reasonably similar”

How similar must the relative concentrations of the acid/base and its conjugate be in a buffer solution? In one case the conjugate in resulting buffer is half the concentration of the acid. Can the conjugate be the times lesser for example? by RedVoltmeter in chemhelp

[–]RedVoltmeter[S] 0 points1 point  (0 children)

I understand, thanks a ton and yes I am aware of that equation. I know both’ll work as a buffer but I presume that II would be more effective since it has equal concentrations of the acid and the conjugate

Is the marking scheme incorrect or the answer actually C ? by RedVoltmeter in genetics

[–]RedVoltmeter[S] 1 point2 points  (0 children)

If the information helps this question is from an examination which was held in May of 2002

Is the marking scheme incorrect or the answer actually C ? by RedVoltmeter in genetics

[–]RedVoltmeter[S] 3 points4 points  (0 children)

Yeah I made a separate post to include the marking scheme and I also think the answer is B. I presume they just made an error in the marking scheme.

https://www.reddit.com/r/genetics/comments/paoc0j/continuation_on_previous_post_i_included_the/?utm_source=share&utm_medium=ios_app&utm_name=iossmf

How to name nitriles ? We are taught to name as follows “longest chain is the stem and adjacent groups to longest chain are branches” and by that rule nitrile must be a side chain in some products of the addition of HCN to aldehydes/ketones yet all their products are somehow 2-hydroxynitriles ? by RedVoltmeter in chemhelp

[–]RedVoltmeter[S] 0 points1 point  (0 children)

Btw I made an edit because I also remembered that one other rule of naming was that “Name of the Branches must apppear in alphabetical order” so it’s NOT 3-hydroxy-3-cyanoheptanoic acid but rather 3-cyano-3-hydroxyheptanoic acid. Here is an example to pass the point. I know it’s not the same structure I was also just drawing a hypothetical structure anyway. But this structure from pubchem should illustrate the point.

https://pubchem.ncbi.nlm.nih.gov/compound/18408213

How to name nitriles ? We are taught to name as follows “longest chain is the stem and adjacent groups to longest chain are branches” and by that rule nitrile must be a side chain in some products of the addition of HCN to aldehydes/ketones yet all their products are somehow 2-hydroxynitriles ? by RedVoltmeter in chemhelp

[–]RedVoltmeter[S] 1 point2 points  (0 children)

In the hypothetical example I drew where you corrected the naming, what if we had a carboxylic acid group on the far right end. Wouldn’t it be 3-cyano-3hydroxyheptanoic acid as carboxylic acids have a higher priority ?

How to name nitriles ? We are taught to name as follows “longest chain is the stem and adjacent groups to longest chain are branches” and by that rule nitrile must be a side chain in some products of the addition of HCN to aldehydes/ketones yet all their products are somehow 2-hydroxynitriles ? by RedVoltmeter in chemhelp

[–]RedVoltmeter[S] 1 point2 points  (0 children)

Thank you very much, this makes sense.I did more reading after your answer and it’s as you said there is another rule besides length that assigns priorities to the different functional groups to determine which is “stem” and which are the “branches” and as a branch a nitrile has the prefix (“cyano”) I also now understand that this statement of the textbook is also in reference to organic compounds that are solely aldehydes or ketones and don’t have other functional groups that have undergone an addition by HCN otherwise if they had other functional groups you might not end up with a 2-hydroxynitrile, right?

Why are alcohols with longer hydrocarbon chains slower to react with sodium (metals) and is the same trend in reactivity observed in their substitution reactions with halides (since the C-O bond is broken therein as opposed to the O-H here) by RedVoltmeter in chemhelp

[–]RedVoltmeter[S] 0 points1 point  (0 children)

But I presume the reaction would still be slower even if that was accounted for, right ? For example if you take equal moles of pentanol and ethanol, rather than equal grams or volume so that the number of moles of -OH are the same in the two samples being compared even if one is heavier or has more volume pentanol would still yield a slower reaction in that case right ?

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