the atomic wt. of two elements A and B are 40 u and 80 u respectively. if x g of A contains y atoms, how many atoms are present in 2x g of B?
Reason this out.
mols = grams/atomic mass
mols A = x/40
mols B = 2x/80 = x/40
Since there are the same number of mols of A and B there must be the same number of atoms of A and B. Therefore, since A contains y atoms then B must contain y atoms.
To find the number of atoms present in 2x grams of element B, we need to use the concept of the Avogadro constant and molar mass.
1. Calculate the number of moles of element A:
The molar mass of element A is given as 40 u, so the number of moles of element A can be determined using the equation:
Number of moles = Mass of substance / Molar mass
Since x grams of element A contains y atoms, we know that the molar mass of A is equal to the mass of one atom. Therefore, the number of moles of element A is:
Number of moles of A = x grams / 40 u
2. Calculate the number of atoms in 2x grams of element A:
To find the number of atoms in 2x grams of element A, we need to use Avogadro's constant (6.022 x 10^23 atoms/mol), which represents the number of atoms present in one mole of a substance:
Number of atoms of A = Number of moles of A x Avogadro's constant
Number of atoms of A = (x grams / 40 u) x (6.022 x 10^23 atoms/mol)
3. Calculate the number of moles of element B:
The molar mass of element B is given as 80 u. We can calculate the number of moles of element B by using the same formula as used for element A:
Number of moles of B = (2x grams) / 80 u
4. Calculate the number of atoms in 2x grams of element B:
Now, we can calculate the number of atoms in 2x grams of element B by multiplying the number of moles of B by Avogadro's constant:
Number of atoms of B = Number of moles of B x Avogadro's constant
Number of atoms of B = [(2x grams) / 80 u] x (6.022 x 10^23 atoms/mol)
So, the number of atoms present in 2x grams of element B can be found using the calculations described above.