Question

using only these supplies, which two questions can mona investigate with an experiment?
does yeast release more carbon dioxide when mixed with 90°f water or when mixed with 110°f water?
does yeast release more carbon dioxide when mixed with 90°f water and 1 teaspoon of sugar or when mixed with 90°f water and 1 teaspoon of baking soda?
does yeast release more carbon dioxide when mixed with 90°f water and 1 teaspoon of sugar or when mixed with 90°f water and 1 teaspoon of salt?
does yeast release more carbon dioxide when mixed with 110°f water and 1 teaspoon of sugar or when mixed with 110°f water and 2 teaspoons of sugar?

Explanation:

To determine which questions can be investigated, we analyze the variables (water temperature, type of substance added, amount of sugar) and if they can be tested with the given supplies. The first question tests temperature (90°F vs 110°F water) with yeast, which is a single variable change. The fourth question tests sugar amount (1 vs 2 teaspoons) with 110°F water, another single - variable change. The second and third questions involve comparing different substances (sugar vs baking soda, sugar vs salt), but the problem likely expects single - variable experiments (temperature or sugar amount as the variable). Wait, actually, the first question changes temperature (independent variable: water temperature, dependent: CO₂ from yeast) and the fourth changes sugar amount (independent: sugar amount, dependent: CO₂ from yeast). These are valid experimental questions as they have one independent variable. The second and third compare different substances, which is also a valid variable (type of additive), but maybe the intended ones are the first (temperature) and fourth (sugar amount) as they are about changing one factor (temperature or quantity of sugar) while keeping others (yeast, water type except temp for first, water temp 110°F for fourth) constant.

Answer:

1. Does yeast release more carbon dioxide when mixed with 90°F water or when mixed with 110°F water?
2. Does yeast release more carbon dioxide when mixed with 110°F water and 1 teaspoon of sugar or when mixed with 110°F water and 2 teaspoons of sugar?