I want to ask here how do I construct a model car power/propel/move by CO2(As a result from the mixing of Acetic Acid + Sodium Bicarbonate/Vinegar + Baking Soda).(The car is also loaded with 100ml of water)

One restricted rule is that there must NOT have any liquid leakage

So I did try to search the internet, most I got is they use CO2 Cartridge[Which is prohibited in the competition], so then....most results turn to be car power by hydrogen and etc.

I also tried channeling the CO2 from the reactor into a small tube to move the wheel, but somehow the air thrust is too weak to push the wheel of the car(As the car is loaded with 100ml of water) and the reaction produce a small amount of CO2 to push the wheel to a a further distance which is not significant.

I also tried using the rocket's principle to try to move the car, it turns out that the car can move quite a distance, which is a good thing, however, as the cork stopper which is stuck at the mouth of the bottle is being pushed out[due to high pressure in the bottle as the result from the reaction], the solution inside the bottle was push out together as well, therefore, there's a liquid leakage, so how I do fix this problem?

Or is there other way that I can build this model car?

Thanks ^^

Are there material usage restriction? Eg tubing, container etc.

Erm tubing all should be alright, it stated there that "There is no mechanical starting"<--not sure quite it means, but if the gas[but i tried...the gas was too weak and not much] use to turn turbine or anything should be alright, but the "fuel" must only be the reaction from Acetic Acid + Sodium Bicarbonate, not other fuel such as battery and etc.

Try using a valve system instead? That way if the pressure gets too much the valve will just shut itself and liquid just won't leak out (with the appropriate precautions)

But the thing is I don't know how to make a valve? @@

Hey bro,
With the weight of your car, 100ml of water is too heavy to be moved by such small amounts of CO2 generated by baking soda

U need heavy artillery
U need Coke light + Mentos
The amount of CO2 in sudden release surely produce a lot of pressure, ur car will moveeeeeeeeeeeeeeeeeee

Yeah, thats y i say use the "poping" mechanism or something like rocket...however.."fuel" that i can use it juz Acetic Acid and Baking Soda....it can pop, but the major problem is that when pop, the solution came out together with the pressure and this will automatically disqualify me cause one of the rule is "There must not be any leakage of liquid"..so how do i fix this problem?