Mole Definition and 127 Threads

hello forum I am working on NKBT Perovskite material.My formula is (Na0.5 K0.5)0.5 (Bi)0.5 TiO3 I am using NaNo3,KNO3,Bi(NO3)3.5H2O,TiO2 powders my question is how much powder in grams I have to take according to stichometry. Do I have to work in wt% or in Mole %. is there any difference...

Hi, I'm new to chemistry and the concepts I named in the title are giving a little trouble to understand. Could someone explain me in a clear way what they are ? Thanks !

Mole is just a number. It doesn't really measure anything so why is it a fundamental unit? And with kelvin - it represents the average energy of the atoms/molecules in a compound. Why is it a fundamental unit? Temperature can easily be represented in joules.

I don't know what mole is and I read a lot of answers, is it like a dozen of atom, or is it like a unit, like meter?or is it something else?

Homework Statement A mineral slurry contains 3 components, solids, liquids and toluene. The slurry has 20 wt% solids and 80 wt% liquid. In the liquid portion of the slurry the mole ratio of toluene to water is 1:5.67 Determine the composition of the slurry (solids, toluene and water) in...

As asked above, what is mole fraction solubility? From what I've been taught, it is the following equation: mole fraction solubility = (number of moles of solute)/(number of moles of solute + number of moles of solvent) Is that even correct? In actual fact, there's a question that deals with...

Can someone explain to me these two things? I'm trying to get the average mass of air and it says it is 29g/mol? But what is a mole? I know it's the amount of carbon-12 atoms in 12 grams. What does 12 grams look like?

This is for my chemical engineering class...for some reason, I am struggling with this problem. I'm not quite sure how to connect the dots..I feel like I know how to do this, though. Homework Statement The mass fraction of benzene in a benzene-toluene mixture is 0.450. What is the mole...

Watsup! I'm taking this nano class which is awesome but I am getting stuck on the gen chem material! no bueno. just want to make sure i did this right. Thanks! Homework Statement [/B] "A blend contains 45wt% polystyrene and 55wt% polypropylene. What is the mole fraction of polystyrene in the...

Homework Statement The number of moles of valence electrons in 1 mole nitride ions are? Homework Equations Nitride ion- N3- The Attempt at a Solution The number of electrons are 8. Therefore number of moles should also be 8?

"A mole of sodium chloride is 58.443 g. It will contain 6.022 x 1023 chloride ions and 6.022 x 1023 sodium ions" Why does one mole of sodium chloride contain both a mole of chloride AND a mole of sodium? Why not half a mole of each?:confused:

1mole of diatomic element X2 contains 34 and 40 moles of electrons and neutrons respectively, the isoptopic formula of the element is? Homework Statement 1mole of diatomic element X2 contains 34 and 40 moles of electrons and neutrons respectivelyHomework Equations all the basic ones! The...

i need to get the hang of the mole concept that , 1.008 g of hydrogen constitutes 1 mole atom, whereas 12g of carbon constitute that 1 mole atom! does it mean that these amounts for H & C contains the Avogadro number of atoms?? does it imply the hydrogen is more denser (or heavier or something...

Homework Statement one mole of an ideal gas takes up 0.0225m3 at 0 degrees celsius and 1.01x10(5) pascals. (calculated) hence, calculate the volume of 1 mole of air (ideal) at an altitude of 15km above sea level. average molecular mass of air = 29 amu. T @ altitude of 15km = 0 degrees C...

Homework Statement Ti-6Al-4V is a metal alloy used to make biomaterials. Its composition is 90% Ti; 6% Al and 4% V (mass percentages). (a) What are the mass fractions of Ti, Al and V? (b) What are the mole fractions of Ti, Al and V? Homework Equations Mass fraction = m/mtotal...

Homework Statement You have several identical balloons. You experimentally determine that a balloon will break if its volume exceeds 0.900L . The pressure of the gas inside the balloon equals air pressure (1.00 atm). The air inside the balloon has a constant temperature of 22 C. How many...

Hi Everyone, I am trying to calculate the mass of oxygen and keep running into dead ends and was wondering if anyone could offer any insight. I am trying to find the resulting mass of oxygen in a 6m x 6m x 6m enclosure at standard temperature and pressure when the mole fraction of oxygen...

Homework Statement One mole of neon, a monatomic gas, starts out at STP. The gas is heated at constant volume until its pressure is tripled, then further heated at constant pressure until its volume is doubled. Assume that neon behaves as an ideal gas. For the entire process, find the heat...

Homework Statement We know that for dry air, we have: -78.08% mol N2 ; -20.94% mol O2. This is: - Y(N2) = 0.7808 for nitrogen (the molar fraction in vapor) - Y (O2) = 0.2094 for oxygen Knowing that the Henry's law constants are: for N2 and O2 are 6.51 x 10^7 Torr and 3.3 x 10^7 Torr...

Why is the amount of mole in gms. of an element the same as the its atomic mass. Is it just because $N_a X 1 u = 1$. Am i missing some simple reasoning behind this? Or was the carbon 12 taken exactly to make this valid?

Homework Statement In this calorimetry experiment, O.5 grams of magnesium is dissolved in 100.0 ml (100.0g) of diluted HCL (0.1mol/L) at an initial temperature of 29.50 C. The final temperature is 46.18 C. Q: Calculate the enthalpy change per mole of magnesium. Homework Equations...

Homework Statement How would I relate the molecular mass of ethanol (46.07 g/mol) to its formula (C2H6O) and indicate how much a mole of ethanol would weigh? Homework Equations The Attempt at a Solution

Homework Statement A mixture of NH3 and N2H4 is placed in a sealed container at 300K. The total pressure is 0.5atm. The container is heated to 1200K, when both substances decompose completely according to the equations, 2NH3--->N2+3H2 N2H4--->N2+2H2 After decomposition is complete, the...

It looks like my first post on this did not make it on this forum some how. I came across this statement. Even though \frac{N_i}{N}=X_i, \frac{dN_i}{N}\neq dX_i How does this work? The book offered no help as well as searches on the internet.

Can anyone give an explanation (other than algebraically) as to why one mole of a gas under Standard Temperature and Pressure and behaves like an ideal gas will always have the same volume (22.4 L)?

Homework Statement I have pure ethanol and water. When mixed, the total volume is not the sum of the individual volumes (its a little bit less). A wikipedia graph has shown that a 0.4mol ethanol to 0.6mol to water mixture is ideal to get the most contraction...

How many atoms are in one mole of the element Lead(Pb) -Intrepid Elder

Exam krackers says that the average kinetic energy for a mole of a gas is K.E.avg = 3/2 RT but my chemistry book says that the total kinetic energy for a mole of gas is = 3/2 RT meaning that NA (average K.E. of one molecule) = 3/2 RT These 2 statements are different, for the bottom one...

Homework Statement Hello Everyone! I am solving a lots and lots of questions on Mole Concept but i am getting stuck in this:- Calculate the volume occupied by 5.25g of nitrogen at 26\circ C and 74.2 cm of pressure. The Attempt at a Solution I actually don't know from where should i...

Homework Statement 1) Haemoglobin contains 33% by mass of iron. Each molecules of haemoglobin has two iron atoms. Calculate the relative molecular mass of haemoglobin. 2) The relative molecular mass of water is 18.0. Calculate the mass of water molecule. Homework Equations...

I haven't been able to try all parts of this question yet as I've been running into problems fairly near the start. I've asked for help with it but have just been told 'use the ideal gas law' which is what I tried to do but can't seem to get it right. We have been given answers to parts a, b...

I've had this mole on my chest for as long as I can remember, and it continues to grow, it's around 6mm in diameter, and is more of a Kidney Bean shape, than that of a circle. it has a crack through the middle horizontally, with some little black dots on the top of it. And I can also scratch...

Homework Statement A 10% (by wt) solution of KNO3 would have what molality and what mole fraction Homework Equations mole fraction = moles of KNO3/total moles wt % = # g of solute/total g molality = # moles KNO3/kg H2O The Attempt at a Solution 1 g KNO3/10 g total 1 g KNO3/101.1...

Arginine has a molecular formula od C6H14N4O2 How many moles of C atoms are there in 0.47 mole of arginine What is the equation I would use here

Homework Statement Determine the number of moles of Nitrogen atoms in a sample of C7H5(NO2)3 that has the same number of oxygen atoms as 12.6 grams of sugar. Homework Equations Mole calculationsThe Attempt at a Solution First find the amount of moles of Oxygen in sugar. Multiply 12.6g by...

Homework Statement 1 mole of monatomic ideal gas. P1 = 2 atm V1 = 44.8 L T1 = 1092 K. The path to P2 = 1 atm V2 = 22.4 L and T2 = 273K is P = 6.643E-4 * V^2 + 2/3. Calculate the heat and work. Homework Equations q = nCpΔT w = PΔVThe Attempt at a Solution I attempted to directly plug in the...

Homework Statement Hi folks! :smile: This is just a conceptual question that has arisen during some reading. At one point the author states that for the reaction: CO_2 \leftrightharpoons X_{CO}CO + X_{CO_2}CO_2 + X_{O_2}O_2 where X is the mole fraction of each component at equilibrium...

Homework Statement a sample of 0.6 moles of a metal M reacts completely with excess of flourine to form 46.8 gms of MF2. a)how many moles of F are present in the sample of MF2 that forms? b)which element is represented by the symbol M? Homework Equations NO. OF MOLES=given mass/molar...

Homework Statement Given the equation for Roaults law and Antoine equation for 2 species I need to recast these into a pair of coupled non linear equations to compute the mole fraction of species one and the temperature for given values of vapor fraction and the total pressure, Antoines...

1. Homework Statement The normal boiling points of benzene and toluene aer 80.1C and 110.6C, respectively. Both liquids obey Trouton's rule well. For a benzene-toluene liquid solution at 120C, with the molar fraction of benzene in the solution equalling 0.68, estimate the vapor pressure...

How many Gold atoms are in Gold mass of 2.5g? 15 percent of the mass is pure Gold. So first i found 15 percent of the mass which i used to calculate the number of moles. Then i multiplied the moles by Avogadros number to give me the atoms. Anyone help

Homework Statement A solution of ethanol (eth) and chloroform (chl) at 45°C with xeth = 0.9900 has a vapor pressure of 177.95 torr. At this high dilution of chloroform, the solution can be assumed to be ideally dilute. The vapor pressure of pure ethanol at 45°C is 172.76 torr. (a) Find the...

I'm a bit confused about the terms "mole", "Avogadro's number", "Avogadro's constant" and "the Avogadro constant" and the concept - or concepts - they represent. I'm puzzled about how "amount of substance" differs from "amount", and in what sense this is a dimension if - unlike other dimensions...

So I've been thinking about this problem for quite some time now any help will be appreciated. A sample of C_{2}H_{2}(g) has a pressure of 7.4 kPa. After some time a portion of it reacts to form {C}_6{H}_6 (g). The total pressure of the mixture of gases is then 3.6 kPa. Assume the volume and...

Homework Statement 3 moles of X and 2.8 moles of Y are allowed to react. How much X will actually react? X + 5Y > 3Z Homework Equations Not sure The Attempt at a Solution Not sure

How can you find mole ratios for 3 substance ex 2.94 X 10 to the 5 of NH3 1.56 X 10 to the 5 O2 9.61 X 10 to the 3 CH4

Homework Statement Consider the charging of a lead-acid batter at atmospheric pressure and room room temperature. 2PbSO4 +2H2O -> Pb + PbO2 + 4H+ + 2SO42- How much electrical work must be provided to produce one mole of lead? The Attempt at a Solution We're given the values of Gibbs...

Homework Statement Show that the entropy of one mole of an ideal gas is given by \Delta S = \int \frac{C_v dT+PdV}{T}. 2. The attempt at a solution \Delta S= \frac{dQ}{T}. From the 1st of Thermodynamics, \Delta U= \Delta Q - \Delta W, where W is the work done by the gas. Hence \Delta Q =...

what is the relation between AMU & Mole? also what is the difference between "Molar mass" and "mass" and please, what is mole? I read this on Wikipedia.com: "It is a common misconception that the mole is defined in terms of the Avogadro constant. It is not necessary to know the number...

Ok, so here is my problem: Suppose 2.00 mole of an ideal, monatomic gas is initially at a pressure of 3.00 atm and a temperature of 350K. It is expanded irreversibly and adiabatically against a constant external pressure of 1.00 atm until the volume has doubled. A) Calculate delta S for...