Moles Definition and 202 Threads

People usually dislike people with big birthmarks (I mostly mean sexual attractiveness, but not only). It seems that the presence of moles correlate with something bad in the organism. With what? Is that possibly that the moles can correlate with bad features of character? I have found the...

a) ##T_A=\frac{p_AV_A}{nR}=300.7K, P_A V_A=kL^2=nRT_A##, ##P_B S=k\frac{L}{2}\Rightarrow P_B V_B=k(\frac{L}{2})^2 \Rightarrow P_B=\frac{kL^2}{2V_A}=\frac{P_AV_A}{2V_A}=\frac{P_A}{2}##, ##W_{spring\to gas}=\int_{L}^{L/2}kxdx=-\frac{3}{8}kL^2=-\frac{3}{8}nRT_A####\Rightarrow Q=L+\Delta...

Sadly, I don't even know what I don't know. Could somebody generate a ballpark figure of how many moles of hydrogen you might have in a sphere 2 meters across, 75F and roughly 16 psi? Even with all that information I'm clueless. (I'll now resume twig-fishing for termites...)

Is percent yield based on grams or moles? Thanks.

So I know current is just coulombs/second. Electrons are also in the unit of coulombs, so I can get coulombs to cancel. 7.9C/s/1.602E-29C = 4.93133E29 1/s Now I just need to get mol on top. There are 6.022E23 electron in a mol so 4.93133E29 1/s / 6.022E23 atoms/mol = 8.1889E5 mol/s. Now my...

Here is my work** Can someone please tell me if this is correct? mass = 27.8 g CaCI2 Number of CaCI2 in the compound = (unknown) Number of CI- ions in the compound = (unknown) Number of moles = mass/molar mass To find the number of moles of CaCI2 first you find the molar mass of the compound. 1...

mass = 37.2 g AICI3 (given) number of ions = AI3+ Ions (unknown) number of ions = CI- Ions (unknown) mass = g/formula unit AICI3 (unknown) The ratio of AI3+ Ions to CI- Ions is 1:3 Molar Mass AICI3 (1 x 26.98 g/mol AI) + (3 x 35.45 g/mol CI) = 133.33 g/mol AICI3 molar mass = 133.33 g/mol...

I got a answer by equation the moles i took the n factor of oxalic acid as 2 and the naoh solution came out to be 2M but i got an answer of 4grams but the answer given is 2 grams am i correct ??

Homework Statement calculate the number of moles of potassium manganate required to neutralise oxalic acid. 2KMn)4- + 5H2C2O42-+ 16H+ --> 2Mn2+ + 10CO2 + H2O Homework Equations n = c x V n= m/Ar The Attempt at a Solution Moles of oxalic acid = 5x10-4 Volumeol of KMnO4 = 0.01085dm-3...

Homework Statement Homework Equations Ideal gas law The Attempt at a Solution The solution to this problem assumes the pressure inside the balloon is the same as the outside pressure, i.e. atmospheric pressure. Is this a valid assumption? I would guess otherwise.

Homework Statement Consider the following reaction. 2 HCl(aq) + Ba(OH)2(aq) BaCl2(aq) + 2 H2O(l) ΔH = -118 kJ Calculate the heat when 100.8 mL of 0.500 M HCl is mixed with 300.0 mL of 0.450 M Ba(OH)2. Assuming that the temperature of both solutions was initially 25.0°C and that the final...

Homework Statement without posting all the lab data I am just wondering if this makes sense. I calculated moles Chlorine to moles Copper as 2:1. (seems reasonable to me). Then I calculated mole ratio of water to Copper in hydrated sample as 20:1. (not sure if this is "reasonable " or not...

Homework Statement This is a question from a chemistry book Two oxides of a metal contain 27.6% and 30% of oxygen respectively. If the formula of the first oxide is MO, find that of the second? 3. The Attempt at a Solution In the first MO, if the total amount is 100g, then O is 27.6g...

Homework Statement The vapour density of a sample of N2O4 gas is 35. What per cent of N2O4 molecules are dissociated inNO2? Homework Equations molar mass = 2 * Vapour Density The Attempt at a Solution I tried to solve this question this way, Let the initial number of moles of N2O4=a and...

Homework Statement The ratio of KMnO4 to I2 is given by 2 MnO4 - + 16 H+ + 10 I - ⇌ 2 Mn2+ + 5 I2 + 8 H2O the ratio is 2:5 - The ratio of I2 to S2O3 2- is given by 1 I2 + 2 S2O32- ⇌ 2 I-+ S4O5 2- the ratio is 1:2 therefore n(S2O3 2- ) = n(MnO4 - ) x 5 Homework Equations Why the mole of...

Homework Statement 30 litres of N2 and 30 litres of H2 are taken in Habers process with 50% yield.What is the final composition of the compunds in litres? Homework Equations N2+3H2->2NH3 The Attempt at a Solution N2 + 3H2-> 2NH3 intial: 30 30 0 final: 30 - x/2 30-(3x)/2 (2x)/2 so, 30 - x/2 +...

Homework Statement If CO = 10 moles, then how to find moles of O in CO molecule? Homework Equations If CO = 10 moles, then how to find moles of O in CO molecule? The Attempt at a Solution I don't know how to proceed

Homework Statement (Q.) 3 g of activated charcoal was added to 50 mL of acetic acid solution (0.06N) in a flask. After an hour it was filtered and the strength of the filtrate was found to be 0.042 N. The amount of acetic acid adsorbed (per gram of charcoal) is :Homework EquationsThe Attempt...

Homework Statement Based on your understanding of Avogadro's law. 1000 L steel storage tank contains 88.5 kg of methane gas, CH4. Calculate no. of moles. The Attempt at a Solution one method= no. of moles=mass/molar mass. no. of moles= 88500/16.04= 5517.4 moles.other method= 1 mol= 22.4 liter...

Homework Statement After balancing an equation, there are 1.82 moles of O2. Calculate the number of molecules of O2. given moles. Homework EquationsThe Attempt at a Solution in every O2 molecule, there are 2 moles of O. so if the number of moles of O2 molecule is 1.82. then 1.82*2= 3.65...

In the ideal gas law, the symbol n represents the number of moles of gas. My question is how, given a volume of a certain gas, one determines how many moles one has. My understanding is that a mole in this case denotes a quantity of particles. How does one determine how many moles one has...

Homework Statement A bubble rises from the bottom of a lake of depth 80.0 m, where the temperature is 4oC. The water temperature at the surface is 18oC. Assume the bubble to be in spherical shape and has an initial diameter of 1.00 mm. Assume that the pressure at the surface of the lake is...

Homework Statement 10.00 cm3 of 1.00 mol dm–3 sulfuric acid is fully neutralized by 20.00 cm3 of 1.00 mol dm–3 of sodium hydroxide. What is the concentration, in mol dm–3, of sodium sulfate solution produced by the reaction? A 0.33 B 0.50 C 0.67 D 1.00 Correct answer = A Homework Equations...

Homework Statement How many moles of electrons are in 1mL of H2O Homework Equations [/B] 1mL = 1g moles to grams conversion - moles x molar mass = grams mass of 1 electron = 9.109382 x 10-28g moles to molecules = number of moles x avogadro's number (6.022140857 × 1023) The Attempt at a...

is the amount of argon gas to exert 10,000 psi in cylinder will be the same if argon transformed to plasma or the number of moles will be less as plasma is more excited and have higher kinetic energy?

i.If all the calcium carbonate used in set up X was used up for the reaction, what is the amount of moles of carbon dioxide produced during the reaction ? (Ca = 40, C = 12, O = 16) My progress: Molar mass of CaCO3=(40+12+(16*3))gmol-1=100 gmol-1 Molar mass of CO2=12 + 16* 2 gmol-1=44 gmol-1...

Homework Statement A control rod to limit the rate at which a nuclear reactor is working is made from boron which is sealed in a casing. A boron atom (105B) is able to capture a neutron; an atom of lithium (Li) and an alpha particle being produced in the process. As a result helium gas is...

Homework Statement The temperature across the capillary with constant cross-sectional area and length L is given by ##T=T_0e^{-kx}##. Assuming an ideal gas and constant pressure show the number of moles to be: $$n=\frac{PV(e^{kL} - 1)}{RkLT_0}$$ Homework Equations ##PV=nRT## The Attempt at a...

Homework Statement How many atoms of oxygen are present in 300 grams of calcium carbonate? molar mass of CaCO3 = 100g Homework Equations The Attempt at a Solution I don't know how to proceed. Can anyone please help me out by giving the forulae or steps on how to do this problem.

Homework Statement To a 25ml H2O2 solution, excess acidified solution of potassium iodide is added. The libereated iodine required 20ml of 0.3N sodium thiosulphate solution. Calculate the volume strength of H2O2. Homework Equations Normality = n-factor × Molarity Volume strength = Molarity ×...

Homework Statement A gas bottle contains exactly 158 moles of carbon dioxide CO2. Find the change in the internal energy of this much CO2 when it is cooled from 36C down to exactly 25C at a constant pressure of 1 atm. The gas can be treated as an ideal gas with γ=1.289. The gas constant reads...

Homework Statement When a problem says 76 moles of P4O10 contains how many moles of P. I can't seem to see why 76 moles of this molecule would contain more moles in it. Homework EquationsThe Attempt at a Solution I know the answer is 76 moles of P = 76 * 4 but how could a compound P4O10 that...

Homework Statement A 16.00g sample of a mixture of KClO3 and KCl is heated until all the oxgen has been removed from the sample. The product entirely KCl (no O), has a total mass of 9.00g. What is the percentage of KClO3 present in the original mixture? 16.00g mixture 9.00g mixture without...

Good evening, I'm an undergraduate astrophysics student currently doing research, and I wanted to get the opinion of some knowledgable chemists about a particular reaction my professor and I wish to emulate. Using a specific type of laser (Nd: YAG, for example), I'd like to mimic something...

Homework Statement How many moles of chlorine atoms are there in 71g? Given: mCl2=71g nCl2=1.00 mol MCl2=70.9g/mol Homework Equations ? 3. The Attempt at a Solution Not sure how to go about this question. Would it just be n multiplied by 2?

Homework Statement How many hydrogen atoms are there in one mole of hydrogen molecules? Homework Equations [/B] The Attempt at a Solution Is there 6.02x1023 hydrogen atoms in one mole? Is that correct?

Homework Statement In 0.50 moles of CaCO3 how many moles of carbon are present? How many moles of oxygen are present? Given: 0.50 moles of CaCO3 Molar mass is 100.9 g/mol Homework Equations n=m/M The Attempt at a Solution I'm not quite sure how to do this question would I begin by finding...

Homework Statement 2. The attempt at a solution I chose no. 1 only, but the answer is 2&3, I can't seem to see how 10^-6 came about. And for C, I'm not clear how it came about too.. Is it because 1 mole consists of 6x10^23 atoms, so no. of moles of the polymer is 1/(6x10^23) ? And why is 1...

Moderator's Note: THIS HOMEWORK WAS POSTED IN ANOTHER FORUM, SO THERE IS NO TEMPLATE. calculate the change in entropy suffered by 2 moles of an ideal gas on being heated from a volume of 100L at 50C to a volume of 150L at 150C. for the gas Cv=7.88 cal/moleC. I'm really confused in entropy and...

So I am taking the second semester of intro physics and Moles,Molecular mass, Number of Molecules is killing me. I am not really able to solve my homework because I can never get these quantities down. I asked my professor for help during offie hours, however he said he teaches physics not...

Homework Statement How many moles of hydrogen peroxide will be oxidized by 0.0045 moles of potassium permanganate in acidic solution? I am unable to think of how you get started? Homework Equations [/B] n - m/mmThe Attempt at a Solution I've balanced the equation for an acidic solution...

Is there a formula to theoretically determine the number of moles of each ion present when a particular concentration of salt is dissociated in water? I remember from A-level (high school) chemistry that concepts such as the dissociation constant exist but I'm struggling to apply them to...

This is using dimensional analysis, and I'm stuck on this question, but I'll show what I have so far. The questions is: If there is 3.34x1022 atoms in a CH3OH sample. What is the mass of this sample, how many moles are there of this sample, and how many molecules are in this sample? Initially...

Homework Statement You need to produce a buffer solution that has a pH of 5.70. You already have a solution that contains 0.0200 moles of acetic acid. Using the Henderson-Hasselbalch equation calculate the moles of sodium acetate needed to create a buffer with the desired pH? The Ka of acetic...

Homework Statement How many moles of electrons weigh 1 kg? Homework EquationsThe Attempt at a Solution We know the mass of an electron= 9.1*10-31kg. So no of electrons in one Kg will be 1/9.1*10-31. Then we just divide that by 6* 1023 to get the number of moles. But my teacher told...

Homework Statement 2 moles of water undergoes electrolysis at 10A. What is the total volume of the system after 1hr? Homework Equations 4 H+(aq) + 4e−→ 2H2(g) 2 H2O(l) → O2(g) + 4 H+(aq) + 4e− Faraday's Law of Electrolysis Q = n(e-) x F F = 96500C The Attempt at a Solution Initial volume...

Homework Statement A helium balloon is used to lift a load of101N. The weight of the envelope of the balloon is46.5N and the volume of the helium when the balloon is fully inflated is31.5m3. The temperature of the air is 0°C and the atmospheric pressure is 1.00 atm. The balloon is inflated with...

Disclaimer: I've never had a chemistry class in my life. I'm reading a journal article that states the following: S2O32- + 2O2 + H2O → 2SO42- + 2H+ has the standard Gibbs energy of −766 kJ/mol at 25ºC. So, this is energy produced per moles of what?! Reactant? Product? If so, which reactant or...

1. Homework Statement http://postimg.org/image/nuzx91ks7/']How[/PLAIN] many moles of hydrogen are needed to saturate this compound? Homework Equations The Attempt at a Solution http://postimg.org/image/nuzx91ks7/']3[/PLAIN] moles of hydrogen as the benzene ring contains 3 pi bonds. Is...

Homework Statement Here is the question: What weight of neutral red (molecular weight 289) must be dissolved in 1.00 ml to give a =40.0 µM (µmol l-1) solution? Give your answer in MICROGRAMS (µg). Homework Equations Not sure the only one I'm aware of is mole concentration (mol dm^-3) =...