Eudiometer - long thin piece of glassware used to collect gasses and measure their volumes.
acetylene - used in welding and miner's headlamps - when burned in the presence of oxygen you will get carbon dioxide and water as the products.
percent yield - a ratio of what you ACTUALLY have made in a chemical reaction compared to SHOULD have made in a chemical reaction. We made 20 grams, but we should have made 25 grams = 80% yield.
percent error - how far you were off the actual answer. in the above problem its 20% error