Only if mixed with water of a hot temperature. If it's lukewarm or below it should be ok.
The yeast would eventually starve and die.
Depends. If the yeast is exposed to oxygen, it will die. However, if not, it will ferment and create ethyl alcohol in you grape juice.
Depending on the amount of acid added, the yeast not grow as well, and will die if enough is added.
They breathe in the chemical water to get oxygen.
I'm not sure about mold but yeast will die at 100 degrees Fahrenheit.
The yeast die.
it wll die unless it is mixed with water
yes and no some parts of yeast can die and some can live
Yes, Yeast dies at 130 degrees Farhrenheit.
Yes as it bakes the yeast will die
Yes, yeast (even dried yeast) is a living organism and if it is not used/activated in a given time period the yeast cells will die and the yeast will not work in baking/brewing.
Either the yeast consumes all of the food available, or the waste products produced by the yeast cause the yeast to die.