Base Definition and 586 Threads

Homework Statement In my textbook, they don't necessarily explain what happens when we add a base to a weak acid (e.g. acetic acid)...so I was wondering if anyone can tell me if I got it down: -Like if we have acetic acid (which is a weak base) in water, it will form an equilibrium and...

Hi guys, I'm really confused as to what "Base-Emitter Voltage" is. I thought it was the voltage difference between the base and the emitter, but apparently it's no such thing? If you could explain it, that would be fantastic. The reason why I ask is I'm not sure if I'm going to blow up...

Homework Statement An explorer is caught in a whiteout (in which the snowfall is so thick that the ground cannot be distinguished from the sky) while returning to base camp. He was supposed to travel due north for 4.4 km, but when the snow clears, he discovers that he actually traveled 7.8...

What should be the minimum base diameter of a 1 meter cylindrical pole ? What should be the minimum base diameter of a 1 meter cubic pole ? how are these computed ? Does length of the pole impacts the base diameter ?

Hi, I have done quite a bit of looking about and I'm aware that there are many forms of penicillin... While looking at the base structure of penicillin i have found two different kinds... At a guess i'd say one is synthetic and one is natural form? Could someone possibly clear this up for...

Homework Statement Use the information below to answer the following question(s). methyl orange: red at pH < 3.1: orange at pH 3.1-4.4: yellow-orange above pH 4.4 litmus: red at pH < 4.5: purple at pH 4.5-8.3: blue above pH 8.3 thymol blue: yellow at pH < 8.0: green at pH 8.0-9.6...

On my calculator I have a log button which is log to the base 10 and I also have a natural log button. How do I input log to the base 2 on a calculator? So far the only way I know is to go log(x)/log2 = y for instance if I'm trying to find log to the base 2 of the number 24 I go...

Hello all, I am a newbie to topology. Hope someone can help sharpen my understanding. I read a theorem that "if T is a topological space with countable base, then every open cover has a finite or countable subcover" Apparently this is quite intuitive because as in the definition of...

I was trying a simple Darlington circuit with two Darlington-connected NPN transistors. There is an LED in the shorted collectors, connected to a 5V supply, and the base is open. The trivial objective was to see that when you touch two fingers to the base and the supply positive, the LED turns...

Homework Statement If a double-stranded segment of DNA has been found to have 23 purines and 15 thymines, how many guanines are there? Homework Equations purines are adenine and guanine...adenine and thymine should be equal amounts. So, there are 15 adenines. Out of the 23 purines...

Homework Statement Whenever base b is even (b=2k for some integer k) a number H=(d(n-1)d(n-2)...d1d0)b is even <=> d0 is even. Homework Equations The Attempt at a Solution I have formulated a proof for the forward direction (=>) but I am having trouble getting started on a proof for the...

Hello! I was just wondering why the most common base is base 10? It seems kind of arbitrary to me, although I may be overlooking something.

Hi, everyone: I am trying to find a result for the number of bundles (up to bundle iso.) over a fixed base and fixed fiber. For example, for B=S¹ , and fiber I=[0,1] I think that there are two; the cylinder and the Mobius strip. I think that the reason there are...

1. A third baseman makes a throw to first base 38.6 m away. The ball leaves his hand with a speed of 38.0 m/s at a height of 1.4 m from the ground and making an angle of 24.2 degrees with the horizontal. How high will the ball be when it gets to first base? 2. d=V0(t) + 1/2(g)(t^2)...

What is in DNA why can it not read the uracil nitrogenous base during transcription? May I have answer in the molecular level?

Does there exist a database with very specific mathematical definitions, theorems... etc? I've found that some thm's/dfn etc differ from author to author. Not necessarily in meaning, but in the words used to describe them. Is there a place where a precise definition can be found that is agreed...

Homework Statement What I'm supposed to do is to rearrange the this formula -16t^2+Vt+h and solve it for V. V= Initial Velocity t= time (throwing the ball in a parabolic arc) h= height I know what the height is and it is 6ft. I also have the time which is 2.03 seconds. How do I rearrange...

Why is alchemy not real? Did anyone ever figure out how to change base metals into gold? What is the closest anyone has ever come to this? Assuming they haven't , why can't they do it?

I need suggestion on how to make a balloon powered Hovercraft. THE AIM: the aim is to make the hovercraft travell a displacement of tleast 3 meters.. THE CONDITIONS: 1. it has to be powered by no more than a single party balloon. 2. the base of the hovercraft must be a CD. (the...

Hello all, I am new to the forum and hope my question is appropriate for this section. My question is about per-unit notation and calculations. Basically I've been given the resistance, reactance at the primary and secondary windings of a transformer, core losses and inductance, etc. The...

Hi, I have a friend who has a friend who has a data base of 20000+ enteries. This data base was constructed using something called D base nearly twenty years ago. Now, they want to know is it possible to transfer the 20000 odd enteries to a modern data base without having to type in the...

A base is a chemical which reacts with an acid forming water and salt only. Is this definition of base true? If true, metal carbonates are not considered as base (carbon dioxide is also formed during neutralization which violates the definition). Hence, the solution of metal carbonates are...

Homework Statement Hi. I'm reaady to panic right now so if anyone could please take the time to answer my question I would HUGELY appreciate it! I seriously need to get this done soon as I also have a test tomorrow and i just want to cry because I'm getting nowhere... We did a lab...

Hello Physics Forums, Before i get started asking questions i wanted to clarify that i don't need/want a answer, i have an answer after about an hour of searching. The thing is i understand what needs to be done but i do not understand how to do it in C++. I am just hoping to learn from you...

Homework Statement OK so this is my first time actually posting but I have lurked around. I need help with two of my chemistry problems. Problem 1 Decide which one(s) of these answer choices are correct. A buffered solution is one which can be desribed by which of the following...

Just out of curiosity, I was wondering how to solve for x in an expression of the form ax = xb It kinda tripped me out at first.

Yo yo yo. What up homies? I am once again humbled to be in need of your gracious assistance. I did all the work this time. I would just like some fresh minds to double check. I am driving two relays with http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=FMMT493CT-ND" is the...

x^2 - 11x + 22 = 0 the roots are x= 3 and x = 6 what's the base of the numbers? ok what I've done is I found the roots in decimal system which are x1 = (11+sqrt(33))/2 and x2 = (11-sqrt(33)/2 then I said x1 = 3 and x2 = 6 so we have 3 = (11+sqrt(33)/2 <=> 6 = 11+sqrt(33) <=> -5...

Homework Statement a dam of height H has a hole half way down to the base. how far outward from the base does the stream hit the ground? Homework Equations The Attempt at a Solution i think you have to use bernoulli's equation right? first find velocity then distance x right?

Homework Statement f(x,y,z)=exy and x5+y5=64 Find Max and MinHomework Equations ∇F = <yexy, xexy> λ∇G = <5x4λ, 5y4λ> The Attempt at a Solution yexy = 5x4λ xexy = 5y4λ x5+y5=64 No idea where to go from here...

Homework Statement Is H3CC(=O)CH2CH3 more likely to act as a Lewis Acid or Lewis Base? Explain your choice. Same for HCO2H (formic acid)Homework Equations N/AThe Attempt at a Solution Since a Lewis Base donates electron pairs, and the oxygen in H3CC(=O)CH2CH3 has two lone pairs, I reasoned...

http://img19.imageshack.us/img19/2692/chptitration.jpg http://img130.imageshack.us/img130/6351/titrationfigure1.jpg 1.)For the titration of strong acid and strong base, and at the beginning of the curve, how to explain the big amount of base added only increase a little of the pH value...

I recently did an experiment with the following reaction: NH_4^+ + OH^-<-->NH_3+H_2O I added phenolphthlein, which is magenta in the presence of base. Now, I have to explain, after adding certain chemicals why I have certain color. The one color change I am having trouble explaining...

Hello, I've posted this on the pyshics forum but no-one has replied so I thought I might try this one. I have been asked to solve the following problem at work. Unfortunately I haven’t done anything like this since college (over 12 years) and am a bit confused now. We have an assemblied...

Could anyone help with a problem I have been asked to solve at work. Unfortunately I haven’t done anything like this since college (over 12 years) and am a bit confused now. We have an assemblied unit, consisting of an aluminium base and cover with a PCA clamped between. The unit is clamped...

Homework Statement NaOH(aq) + HCl(aq) ------> NaCl(aq) + H2O(l) 50mL of 1.0M HCl and 50ml 1.0M NaOH was mixed. Total heat is 2826J. If the density of 0.5M NaCl produced in this reaction is 1.02g/mL: a) What is the mass of the solution? b) Moles of water formed c) Moles of NaCl formed d) Molar...

base representation please help~ It is known that if asks+as-1ks-1+...+a0 is a representation of n to the base k, then 0<n<=ks+1-1. Now suppose n=asks+as-1ks-1+...+a0 and m=btkt+bt-1kt-1+...+b0 with as,bt not equal to 0, are two different representations of n and m to base k, respectively...

base representation please help~ It is known that if asks+as-1ks-1+...+a0 is a representation of n to the base k, then 0<n<=ks+1-1. Now suppose n=asks+as-1ks-1+...+a0 and m=btkt+bt-1kt-1+...+b0 with as,bt not equal to 0, are two different representations of n and m to base k, respectively...

base current in transistor flows due to recombination of electrons and holes. Explain

Homework Statement The number 4312 in base ten is (4*10^3) + (3*10^2) + (1*10^1) + (2*10^0) 4312 in base six is (4*6^3) + (3*6^2) + (1*6^1) + (2*6^0) which is 980 therefore 4312 in base six is equal to 980 in base 10 QUESTIONS: a) does 124 in base 5 represent an odd number...

Homework Statement I am reading Ramamurti Shankar Quantum mechanics and I have a thing where is "vector base", how can I understand this "vector base"? please tell me what it means that I can ex. solve equation in eigenvector base? what it means that somewhere is a vector base? I need this to...

Homework Statement after titrating sodium hydroxide with hydrofluoric acid, a chemist determined that the reaction had formed an aqueous solution of 0.020 mol/l sodium fluoride. determine ph of the solution Homework Equations The Attempt at a Solution Ka of HF= 6.3X10^-4 NaOH +...

Sorry, this is not a H.W question . But I figure this is the more active section in math, and that maybe some calculus can help. The question is that given a number n, Find which base its a palindrome in. For example, The given number is n = 3. Starting from base 2 to x, we check...

Homework Statement See the pic (I know, its not clear but still). Homework Equations The compound is reacting with a base. The pic shows the alpha hydrogen taken out by the base. Why in both the compounds that alpha H is taken out which is not near Chlorine. Why not the H which is near the...

Can someone guide me on how to express (.a1a2a3a4a5) base n as a quotient of base n integers. There is a bar over a3a4a5.

What is 1/7 in base 2? How would you solve for this? Thanks!

I was wondering if base isolation systems are used in the design and construction of skyscrapers. I was reading up on base isolation systems and they seem to be used in normal sized buildings frequently. Anyways, if anyone could give me some examples of base isolation systems being used in...

\int_0^1\int_0^y e^{x^2} dx dy The region I am integrating over should look like this graph, right? I tried switching the bounds but I am left where what I started. since 0 < x < y, and 0 < y < 1 I can switch to 0 < x < 1 , and x < y < 1 leaving me with the integral...

This is my question: When a 17.9 mL sample of a 0.493 M aqueous nitrous acid solution is titrated with a 0.476 M aqueous barium hydroxide solution, what is the pH after 13.9 mL of barium hydroxide have been added? I'm not really sure how to start it? I have the moles of the acids and the...

Homework Statement Consider a titration in which 50.00 mL of .450 M benzoic acid, C6H5COOH, is reacted with 0.2000 M Ca(OH)2. What will the pH be when 60.00 mL of Ca(OH)2 has been added?Homework Equations 2C6H5COOH + Ca(OH)2 -> 2 H2O + Ca(C6H5COO)2The Attempt at a Solution I have determined...