30cm3 pf hydrogen at s.t.p combine with 20cm3 of oxygen to form steam according to the following equation 2H2(g) + O2(g) → 2H2O(g).
Calculate the total volume of the gaseous mixture at the end of the reaction
- 50cm3
-
35cm3
- 30cm3
- 25cm3
The correct answer is: B
Explanation
2H\(_2\)(g) + O\(_2\)(g) → 2H\(_2\)O(g).
2 volumes of H\(_2\)(g) and 1 volume of O\(_2\)(g) produced 2 volumes of H\(_2\)O\(_2\)
ratio of reacting volumes
30cm\(^3\) + 15cm\(^3\) → 30cm\(^3\)
30cm\(^3\) of Hydrogen requires 15cm\(^3\) of oxygen to produce 30cm\(^3\) of water.
Excess oxygen: 20cm\(^3\) – 15cm\(^3\) = 5cm\(^3\)
Total volume of gaseous mixture: 5cm\(^3\) of Oxygen + 30cm\(^3\) of Water = 35cm\(^3\)