Answer:- none
Explanations:- For naming hydrocarbons we use the suffix -ane, -ene and -yne.
-ane is used when we have only single bonds between all carbons. -ene is used if there is any double bond between two carbons and the -yne is used if there is any triple bond between two carbons.
The given name of the compound is propane. It ends at -ane and so it's an alkane and must have single bonds between all the carbons it has. So, there are zero double bonds present in
.
This is also clear from the below lewis dot structure of the compound.
Answer:- B:
is the right answer.
Solution:- The balanced equation is:

We have been given with 8.75 grams of oxygen and asked to calculate the grams of hydrogen needed to react with given grams of oxygen according to the balanced equation.
From balanced equation, 1 mole of oxygen reacts with 2 moles of hydrogen.
So, let's convert grams of oxygen to moles and multiply it by the mole ratio to calculate the moles of hydrogen that are easily converted to grams on multiplying by it's molar mass.
The complete set up looks as:

= 
Hence, the right option is B:
.
An exothermic reaction releases heat. An endothermic reaction absorbs heat. Burning gas releases heat so it would be exothermic. Acid and water react heating the beaker would be exothermic because it releases heat from the reaction. Hope this helps! ;)
15.6gC3H8*44.1gC3H8*32gO2=11.32
Heat can be absorbed or produced