What weight of oxygen gas will contain the same number of molecules as 56 g of nitrogen gas? (O = 16 u; N = 14 u)
Given mass of nitrogen = 56g
Molar mass of nitrogen = 14g
No. of moles of nitrogen = given mass of the element/ molar mass of the element = 56g/14g = 4 moles
Equal number of moles of all the susbtances contain equal number of molecules.
So, 4 moles of nitrogen and 4 moles of oxygen contains same no. of molecules.
Hence, mass of 4 mole of oxygen = 4 × 16g = 64 g