InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
The thermochemical equation for solid and liquid rocket fuel are given below: `2AI(s) +1(1)/(2)O_(2)(g) rarr AI_(2)O_(3)(s), DeltaH =- 1667.8 kJ` `H_(2)(g) +(1)/(2)O_(2)(g) rarr H_(2)O(l), DeltaH =- 285.9 kJ` a. If equal masses of aluminium and hydrogen are used, which is a better rocket fuel? b. Determine `DeltaH` for the reaction `AI_(2)O_(3)(s) rarr 2AI(s)+1(1)/(2)O_(2)(g)` |
|
Answer» From the first equation a. `2` moles of `AI (i.e. 2 xx 27g = 54 g)` On combustion given hate `= 1667.8 kJ` `:. 1g of AI` givens `rArr (1667.8)/(54) rArr 39.9 kJ` From the second equation: `1"mole of" H_(2)(=2g)` on combustion gives heat `= 285.9 kJ` `:.1 g of H_(2)` gives `rArr (285.9)/(2) rArr 142.95 kJ` Thus, `H_(2)` is a better rocket fuel. b. Writing the reverse of the first reaction, we have `DeltaH = 1667.8 kJ mol^(-1)` |
|