Recipe for making CO2 (Yet to try this)

Recipe from my cousin to make DIY CO2 gas:

1) 8 x 1/2 cup(60ml) tap water + 4 x 1/2 cup(60ml) hot water (ratio 2:1)
2) 5 x 1/2 cup(60ml) sugar
3) 1 x 1/2 tea Spoon(2.5ml) yeast
4) 3 x 1/2 tea Spoon(2.5ml) soda powder (Natrium bicarbonate)