The atomic weight of B is 10.8 g/mol
1. Convert grams of B to moles of B:
moles B = 96.3 g B1 mol = 8.91 mol B10.8 g
Multiply by moles per gram. Grams cancel out.
The atomic weight of S is 32.1 g/mol
2. To convert 8.91 moles of S to grams of S:
grams S = 8.91 mol S32.1 g = 286 g S
1 mol
Multiply by grams per mole. Moles cancel out.
Note that since the atomic weight of S is larger than the atomic weight of B, the mass of the same number of moles is also larger.
Multiplication by what is called a conversion factor. A moles x (bbb grams / 1 mole) in which bbb is the molar mass of the substance.
For this you need the atomic mass of Fe. Take the number of grams and divide it by the atomic mass. Multiply by one mole for units to cancel.82.5 moles Fe / (55.9 grams) = 1.48 moles Fe
For this you need the atomic (molecular) mass of CO2. Take the number of grams and divide it by the atomic mass. Multiply by one mole for units to cancel. CO2=44.0 grams454 grams CO2 / (44.0 grams) = 10.3 moles CO2
.8 moles
Using the formula number of moles = mass divided by molar massso mass = number of moles X molar massFind molar mass by adding up the masses of all the atoms in your substance.A good way to remember this is as the formula g/mw = moles, and the mnemonic for this is"Mine workers (mw= molecular weight) under ground (grams of compound you are dealingwith = Moles!
Multiply the number of moles (0.0976) by the molar mass of C9H8O (9*12.0+8*1.008+16.0= 132.1) in units: moles * grams/mole = grams
A sample of Se weighs 20.5 grams. Will a sample of V that contains the same number of atoms weigh more or less than 20.5 grams? (more, less): _______Calculate the mass of a sample of V that contains the same number of atoms. _______ grams of VAnswer:Since the atomic weight of V is smaller than the atomic weight of Se, each atom will have a smallermass, and the sample will weigh less.Since the same number of moles will contain the same number of atoms, regardless of the element, it is only necessary to find the number of moles of Se in the 20.5 gram sample, and then to find the mass of the same number of moles of V.The atomic weight of Se is 79.0 g/mol1. Convert grams of Se to moles of Se:moles Se= 20.5 g Se1 mol = 0.260 mol Se79.0 gMultiply by moles per gram. Grams cancel out.The atomic weight of V is 50.9 g/mol2. To convert 0.260 moles of V to grams of V:grams V = 0.260 mol V50.9 g = 13.2 g V1 molMultiply by grams per mole. Moles cancel out.
A 42.7 gram sample of potassium nitrate (KNO3) contains how many grams of potassium?
A mole is a defined number of atoms/molecules of an element/compound. Therefore, the number of moles of NaCHO3 will depend on the mass of NaCHO3 that you have. To calculate the number of moles in a known sample, divide the mass of the sample (in grams) by the molecular weight.
Potassium has atomic number 39.1.Amount of K in 284g sample = 284/39.1 = 7.26molThere are 7.26 moles of potassium in a 284g sample.
Multiplication by what is called a conversion factor. A moles x (bbb grams / 1 mole) in which bbb is the molar mass of the substance.
Number of moles = mass of the sample/atomic weight of Al = 96,7/26,987 = 3,58
100 grams oxygen (1 mole O/16 grams)(2 mole Fe/3 mole O) = 4.17 moles iron --------------------------
The quantity that serves as a conversion factor between mass and number of moles is the molecular mass.
Which sample contains the greatest number of atoms. A sample of Mn that contains 3.29E+24 atoms or a 5.18 mole sample of I?The sample of _____ contains the greatest number of atoms.Answer:In order to compare the two samples, it is necessary to express both quantities in the same units. Since the question was phrased in terms of atoms, it is convenient to convert moles of I to atoms of I.The conversion factor between atoms and moles is Avogadro's number: 6.02 x 1023 "things" / molTo convert 5.18 moles of I to atoms of I:atoms I= 5.18 mol I6.02 x 1023 atoms I = 3.12E+24 atoms I1 mol IMultiply by atoms per mole. Moles cancel out.The sample of Mn contains 3.29E+24 atoms.Since 3.12E+24 is smaller than 3.29E+24, the sample of Mn contains the greatest number of atoms.
Each mole of boron atoms has a mass of 10.811 grams, as indicated by the gram atomic mass or weight of boron. Therefore, 585 moles has a mass of about 6.32 X 103 grams, to the same number of significant digits as 585.
The atomic weight of Cr is 52.0 g/mol1. Convert grams of Cr to moles of Cr:moles Cr = 45.6 g Cr1 mol = 0.877mol Cr52.0 gMultiply by moles per gram. Grams cancel out.The atomic weight of Co is 58.9 g/mol2. To convert 0.877 moles of Co to grams of Co:grams Co = 0.877 mol Co58.9 g = 51.7 g Co1 molMultiply by grams per mole. Moles cancel out.Note that since the atomic weight of Co is larger than the atomic weight of Cr, the mass of the same number of moles is also larger.