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When phosphours `(P_(4))` is heated in limited amount of `O_(2).P_(4)O_(6)` (tetraphosphorous hexaoxide) is obtained, and in excess of `O_(2)`, `P_(4) O_(10)` (tetraphosphours decaoxide) is obtained. i. `P + 3 O_(2) rarr P_(4) O_(6)`, ii. `P_(4) + 5O_(2) rarr P_(4)O_(10)` What mass of `P_(4) O_(6)` will be produced by the combustion of `2.0 g` of `P_(4)` with `2.0 g` of `O_(2)`.A. 0.0145 molB. 0.0072 molC. 0.029D. 0.0048 |
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Answer» Correct Answer - B Mol of `O_(2) = (2.0)/(31 xx 4) = 0.016 "mol"` This is not enough `O_(2)` to produce `P_(4) O_(10)`, which would have required `5 xx 0.016 = 0.08` mol `O_(2)`. Thus, `(0.016 "mol" P_(4)) ((3 "mol"O_(2))/("mol"P_(4)))` `= 0.048 "mol" O_(2)` used to make `P_(4)O_(6)` Mol of `O_(2)` unreacted `= (0.0625 - 0.048) = 0.0145 "mol" O_(2)` This `O_(2)` can react according to the equation `P_(4) O_(6) + 2 O_(2) rarr P_(4) O_(10` Then, `(0.0145 "mol" O_(2)) ((1 "mol" P_(4) O_(10))/(2 "mol" O_(2))) = 0.00721 "mol" P_(4) O_(10)` the `0.016 "mol of" P_(4) O_(6)` orginally formed, `0.00725` mol is converted to `P_(4) O_(10)`, leaving `(0.016 - 0.00721) = 0.009 "mol" P_(4) O_(6)` `(Mw "of" P_(4) O_(6) = 220)` Weight of `P_(4) O_(6) = 0.009 xx 220 = 1.98 g P_(4) O_(6)` |
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