InterviewSolution
Saved Bookmarks
| 1. |
Convert into moles : (a) 12 g of oxygen gas (b) 20 g of water (c ) 22 g of carbon dioxide (Atomic masses : `O = 16 u, H = 1 u` and `C = 12 u`) |
|
Answer» (a) Oxygen gas consists of `O_(2)` molecules . So, molecular mass of oxygen gas `(O_(2)) = 16 xx 2 = 32 u` Now, 1 mole of oxygen gas = Molecular mass of ox ygen in grams `= 32 g` If 32 g of oxygen gas `= 1` mole Then 12 g of oxygen gas `= 1/32 xx 12` mole `= 0.375` mole (b) Water consists of `H_(2)O` molecular mass of water `(H_(2)O) = 1 xx 2 + 16 = 18 u`. Now, 1 mole of water = Molecular mass of water in grams ` = 18 g` If 18 g of water `= 1` mole Then 20 g of water = `1/18 xx 20` mole `= 1.11` mole (c ) Carbon dioxide consists of `CO_(2)` molecules. So, molecular mass of carbon dioxide `(CO_(2)) = 12 + 1 xx 2` ` = 12 + 32 = 44 u`. Now, 1 mole of carbon dioxide = Molecular mass of carbon dioxide in grams `= 44 g` If 44 g of carbon dioxide = 1 mole Then, 22 g of carbon dioxide `= 1/44 xx 22` mole `= 1/2` mole `= 0.5` mole |
|