That is called condensation
For 23., you have to find a way to measure your heart rate not increase it. search it up on google.
Answer: 15.8 g of
will be required to produce 1.60 grams of 
Explanation:
To calculate the moles :

According to stoichiometry :
As 1 mole of
is given by = 2 moles of 
Thus 0.05 moles of
is given by =
of 
Mass of 
Thus 15.8 g of
will be required to produce 1.60 grams of 