Answer:I think it’s A.Positive. Not sure though.
Explanation:
Answer : The molecular weight of this compound is 891.10 g/mol
Explanation : Given,
Mass of compound = 12.70 g
Mass of ethanol = 216.5 g
Formula used :

where,
= change in freezing point
= temperature of pure ethanol = 
= temperature of solution = 
= freezing point constant of ethanol = 
i = van't hoff factor = 1 (for non-electrolyte)
m = molality
Now put all the given values in this formula, we get


Therefore, the molecular weight of this compound is 891.10 g/mol
See the image below.
An excited electron is in a <em>high-energy state</em>.
When it drops to the lower-level ground state, it must get rid of this excess energy by <em>emitting it</em> as a quantum of light.
Answer:
C3H8 + 5O2 => 3CO2 + 4H2O
Explanation:
Hydrocarbon combustion is the reaction between a hydrocarbon and O2 producing CO2 and water.
C3H8 + O2 => CO2 + H2O
First we balance the C and H.
C3H8 + O2 => 3CO2 + 4H2O
Now we balance O for the answer!
C3H8 + 5O2 => 3CO2 + 4H2O