If 24. 7 g of no and 13. 8 g of o₂ are used to form no₂, how many moles of excess reactant will be left over? 2 no (g) + o₂ (g) → 2 no₂ (g).

17 a tourist was planning a trip by car for travelling at some constant speed for 2.5 hours. however, he found that if he increases the speed by 20 km/h he can cover the same distance in 30 minutes less time than it was planned. what was the planned speed of the tourist, in km/h?