Homework Help

Ok, I understand that mole is 6.02x 10^23. My teacher gave me this question Moles of Sodium Barcarbonate in a teaspoon Mass of Teaspoon: 10.02g Mass of Teaspoon of Sodium Bicarbonate: 20.19g Sodium Bicarbonate: NaHCO3 what is the mole, molecules, and oxygen atoms. Could someone please explain to me how to do this.I really don't understand

Hi all, I'm working out various Fermi Temperatures of substances (potassium, neutrons in a neutron star etc) and have come to Liquid 3He (density 81kgm-3). I've been told that these are not electrons when considering liquid Helium, but I'm at a loss of how to proceed. Has anyone got any ideas? Thanks!

When and Where Germany can invite world tourists to travel on north sea floor to travel in Frisian Islands ?

Do you think Music's effects on plant growth would be an approporiate biology experiment for extended essay (IB) ? I know that have "music" as a variable sounds silly, but how could I set the variables so that the lab can be analysed in depth ?

Hi all, having difficulty with this problem: A B0 star has a luminosity of ~ 16000 L(solar) and a mass of ~ 16 M(solar). Can you estimate the time on the main sequence for this star simply from considering the rest mass energy of the core of the star (~10% of the total, and fusion burns with an efficiency of about 0.7%) and its luminosity? Not really sure where to start, am very new to Astro stuff...

A 2 kg mass (m1) and a 3 kg mass (m2) are attached to a lightweight cord that passes over a frictionless pulley. Assume the positive direction of motion to be when the smaller object moves upward and the larger mass moves downward. Okay...I went around trying to solve this as a normal tension problem...going like this: T - (m1)g = (m1)a and T - (m2)g = (m1)a (g = 9.8, a = acceleration) therefore: T = (m1)a + (m1)g and T = (m2)a + (m2)g (m2)a + (m20g = (m1)a + (m2)g solving that gives: a = 9.8 (meters per second squared) the answer key says: 1.96 (meters per second squared) My answer makes more sense to me...but I ha…

Hi. I did a lab in chemistry where we put a test tube of paradichlorobenzene in hot water and recorded the temperatures of water and PDB. For the writeup we have to graph the heating curve of PDB, time vs. temperature. One of the questions is; What would the graph look like if the amount of PDB was cut in half? I think that the plateau of the curve would be cut in half because it would take half as much time to melt the PDB, are there any equations that I can use to prove whether this is correct or not?

IN order to investigate the action of bacterial membrane protein that is a light-driven proton pump, you purify protein and allow it to self-assemble together with phospholipids into liposomes that also contain an indicator dye,which is blue at high pH,colorless at neutral pH,and red at low pH.You then expose the liposomes , in an aquaeous solution, to sunlight.The interior of the liposomes stay colorless.Assuming that your bacterial protein has not been damaged by its purification and incorporation into liposomes, what it the most likely explanation for this results?

Hi, Can you help me on doing the steps to answer this problem? Given: Mass of Salt = 10 grams Total Volume = 1 litres --> the salt is dissolved into this volume to make a solution. pH of the Solution = 13.07 --> salt is completely ionized in the solution. Required: Molecular Weight of the salt. Correct me: (given the mass; we need to find the number of mole) Step 1 - find concentration using the pH. pH = -log[A], where [A] is the concentration of the solution. Step 2 - find the number of moles is the solution. n (# of moles) = Volume (total volume) x Molarity (from step one) Step 3 - find the molecular weight by dividing the mass by…

Catalase is used to break up hydrogen peroxide into water and oxygen. I can demonstrate this on a potato by cutting it up and dripping the substance on it, but how do I prove that the bubbling gas released is oxygen? I can tell from the chemical equation, but the question needs me to demonstrate something practically. Is it possible to prove that it is oxygen by dipping a piece of pure iron into the foam and see if it rusts?

I know the enzyme maltase woks on the substrate maltose and cellulose synthase on cellulose etc., but the question also asked me to give the name(s) the enzymes that work on a general protein and a general lipid. Is there an enzyme that works on all proteins or lipids or something? I thought they were very specific...

can some1 give me some info about how is chemistry related to DNA mutation. i would also b thankful if some1 could give some websites with related info...thanks in advance

1. The problem statement, all variables and given/known data A 0.4m diameter, 50KG, solid pulley wheel is used to derive a conveyor belt system on a production line. The belt is very light and it's mass can be taken as zero. The pulley wheel is accelerated from rest at 2 rads/s^2 for 3 secs, then rotated at a constant velocity for a further 10 secs, before being decelerated uniformly back to rest in 2 secs. 1) How far does the belt move during the whole 15 secs? 2) What power is required to accelerate the pulley wheel during the acceleration phase (i.e) during initial 3 secs. 2. Relevant equations (a) w(angular velocity) = Wo (Intial angular velocity) + &…

what is a good science project that can show you something about our solar system it needs to be 3-d needs to explain something needs to be cheap needs to be done in 1 week and i cant do the planets rovolve around the lightbulb thing what is a good 3-d science project please i need your ideas.

Do I have to memorize the eight steps of the Krebs Cycle to pass the AP Exam? Will there be questions that require me to know all the chemical changes of each step?

Hello, I really need help with my homework. I really have a hard time with science and I try really hard. Can someone check if my answers are right? I tried the best of my ability to answer these so please help me out. the star means the answer i think it is. 1. How many protons should be added to the nucler of oxygen atoms so the resulting gas will flow red when an electric current flows through it? A. 1 B. Protons have to be subtracted not added.* C. 4 D. 2 E. 3 2. One element is distinguished from another by number of A. Protons B. Neutrons C. Electrons D. All of the above.* 3. Which of these atoms has the greatest amount of electrical charg…

I need some help on a few things I can't seem to find in either my book, nor my notes. I'm doing a phsyical science review paper, including definitions, and questions which is due tomorrow, and I've missed a bit of school already. So, some things I need help with are: 1.)At what temperature water has its greatest density? 2.)What part of the atom dictates its chemical properties? 3.)Given the atomic mass and atomic number, how do I calculate the number of protons, electrons and neutrons are in that element? 4.)How an atomic spectrum is made. 5.)How many valence electrons are in the main group of elements of the periodic table? 6.)What 7 diatomic el…

Hello SFN, I am an occasional lurker who has a question. Well, more or less an inconsistency. This problem was something along the lines of : Find the anti-derivative of (2x + 1)^3. and the inital value if g(1) = 100 The anti-derivative should be : ((2x + 1)^4) / 8 + c And c would come out to be 89.875. I assume we could expand (2x+1)^3 to 8x^3 + 12x^2 + 6x + 1 and proceed to find the anti-derivative, 2x^4 + 4x^3 + 3x^2 + x + c. If we use g(1) = 100, you come up with c = 90. My question is : where is the 1/8 difference coming from? Thanks for your help, RandallJ

Hey Guys, I'm new here, my name is Alex. I'm having a lot of trouble with Chemistry and we are doing Reaction Predictions right now. Ok in this worksheet, I'm given a bunch of reactants and I'm expected to: 1. Tell what type of reaction might be expected 2. Whether the reaction will occur or not 3. If not, why it will not occur; then write the symbols and formulas for the reactants 4. If so, what the balanced equation for the reaction is 5. In the case of double displacement reactions, whether the reaction goes to completion or not ok for number 1 they gave me tin and copper (ll) sulfate Sn+ Cu(SO4)2 Ok I have a lot of questions. Did I wr…

What is the final pH of a solution obtained by mixing 200 ml of 0.400 M NH3 with 300 ml of 0.100 M HCl? (Kb = 1.8 x 10^-5) I used an ICE table and came up with 9.68. Is that correct? Should I have used two ICE tables instead of one? The first in the one direction and the second going back in the other direction?

In a simple harmonic motion, the tension is greater than the component of weight along the rope by mv^2/r right?

Hello, I am doing an experiment/essay on acid rain... and I need to formulate a reasearch question. so,, I was wondering . Are nitric, sulfuric, and carbonic acid components of acid rain. ? If so, why would there be three different types of acid rain and what would be the extent of their respective damage to a plant's growth ?

I was wondering if anyone knows how to calculate joels. and kinetic energy and stuff. I really need help. can any 1 teach me how to do it?

This appears to be the most relevant forum so here I go... I have to do an Essay on Macbeth, which I'm struggling a lot with. Since this is a place of literature I feel that someone would be able to help me out, which I am in dire need of. The essay has to anwser the following: equivocation and explain gow it leads to Macbeth's downfall. Now, if anyone could confirm these following quotes as being relevant and thoughtful, please do so: - "This supernatural soliciting Cannot be ill, cannot be good. If ill, Why hath it given me earnest of success… If good, why do I yield to that suggestion" - "And oftentimes, to win us to our harm, The instruments of darkness tell us trut…

I am doing max/min problems in calculus. The problem is to maximize the volume of a rectangular box with edges parallel to the axes that can be inscribed in the ellipsoid x^2/4 + y^2 + z^2/9 = 1