First of all, we should know what a mole and molar mass of an element means. Then answering this question would be easy.
Mole is a number( like pi, 1, 2, etc.). It is approximately 6.0225 *1023 . 1 mole of anything is same as the number of atoms in 12 grams of Carbon C12 sample. The mass of mole of an element/compound is called it's molar mass expressed in grams. The molar mass of a monoatomic element is equal to it's mass number.
So, we know Ca's mass number = 40.
that means 1 mole of Ca weighs 40 grams.
=>1/40 mole of Ca weighs 1 gram.
=>(1/40)*23 moles of Ca weighs 23.0 gram.
=>0.575 moles of Ca weighs 23.0 gram.
So there are 0.575 moles of Ca atoms in 23.0g of Ca
1 mole Ca = 40.078g
30.0g Ca x 1mol/40.078g = 0.749mol Ca
24 g calcium is equivalent to 0,6 moles.
26,0 g of Ca equal 0,649 moles.
1 mole
3 x 2 x 23 = 138g
atomic waight of hydrogen = 1.0079 weight of one mole of hydrogen = its atomic mass in grams(just like all elements). therefore 454g/1.0079g = 450.4 moles of hydrogen.
Molarity = moles of solute/Liters of solution ( 300 ml = 0.300 Liters ) For our purposes, Moles of solute = Liters of solution * Molarity Moles NaCl = 0.300 Liters * 0.15 M = 0.05 moles NaCl =============
1.56 X 10^21 atoms of sodium ( 1 mole Na/6.022 X 10^23) = 0.00259 moles sodium or 2.59 X 10^-3 moles sodium
About 265,000,000,000,000,000,000,000. (2.65 X 10^23)
22.98977 grams.
6.066 into 10(up 23 )
each mole contains 6.022*10(raised to the power 23) so three moles of sodium contain 18.066*10(raised to the power 23) mass of one mole of sodium is 11 grams so mass of three moles of sodium is 33 grams
Atomic Weight sodium = 23 so 46/23 = 2 moles of sodium in 46.0g
3 x 2 x 23 = 138g
3 x 2 x 23 = 138g
23 grams iron ( 1mole Fe/55.85 grams) = 0.41 moles of iron
The answer is o,5 mol.
atomic waight of hydrogen = 1.0079 weight of one mole of hydrogen = its atomic mass in grams(just like all elements). therefore 454g/1.0079g = 450.4 moles of hydrogen.
Molarity = moles of solute/Liters of solution ( 300 ml = 0.300 Liters ) For our purposes, Moles of solute = Liters of solution * Molarity Moles NaCl = 0.300 Liters * 0.15 M = 0.05 moles NaCl =============
A mole of an element or compound is 6.022 x 1023 (Avogadro's constant) molecules of that substance. This number is the number of molecules it takes for an amount of substance to have a mass in grams the same as its molecular mass: carbon has a molecular mass of 12, so 6.022 x 1023 (one mole) carbon atoms have a mass of 12 grams. The molecular mass of sodium is 23 (22.989) so one mole of sodium has a mass of 23 grams. Sodium chloride has a molecular mass of 58.44 so a mole of NaCl is 58.44 grams. One mole of sodium will make one mole of sodium chloride. Na + Cl => NaCl So four moles of sodium will make four moles of sodium chloride. 4Na + 4Cl => 4NaCl Four moles of NaCl has a mass of 4 x 58.44 = 233.76 grams.
1 mole of Sodium Chloride weighs 58.5 grams (1 mole is the same as the molecular weight of a compound. The molecular mass of Sodium Chloride- NaCl is 23 [Na atomic mass] + 35.5 [Cl atomic mass] which is equal to 58.5 grams).Thus 10 moles would weigh 10x58.5 grams = 585 grams.The answer is 585 grams.