Explain the task to each other again in your own words.

State what you understood the task to be and what is still unclear to you.

We’re supposed to figure out why a vintner takes a candle into the wine cellar for safety reasons.

Think about the dangers that a vintner can encounter in a wine cellar.

What happens in a wine cellar?

Wine is stored in a wine cellar.

Alcoholic fermentation takes place in the barrels.

Recall what you have learned about alcoholic fermentation.

During alcoholic fermentation, alcohol is produced from sugar by yeast.

C₆H₁₂O₆ → 2 C₂H₅OH + 2 CO₂ + energy

From the reaction equation, we see that CO₂ is formed as a by-product.

What do you know about carbon dioxide?

CO₂ is formed during many combustion processes and during respiration.

It is invisible and odorless, and at higher concentrations it can cause suffocation.

Now you know the danger that could lurk in the wine cellar. How can a candle help avoid this danger?

A candle flame goes out if there is no longer enough oxygen in the air and if the concentration of CO₂ has increased significantly.

Now you have all the information you need to give and support an answer.

The vintner takes a candle into the cellar to determine whether too much CO₂ is in the air.

CO₂ is formed as a by-product during alcoholic fermentation. If the CO₂ concentration in the cellar is high, the vintner could suffocate.

With a candle in his hand, he is warned in time because the flame goes out.