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
We are asked to convert from units of kilometer per second to units of miles per year. To do this, we need a conversion factor which would relate the different units involved. We either multiply or divide this certain value to the original measurement depending on what is asked. From literature, we will find that 1 mile is equal to 1609 meters and 1000 m is equal to 1 kilometer. Also, we will find that 3600 s is equal to 1 hr, 24 hr is equal to 1 day and 365 days is equal to 1 year. We do the conversion as follows:
3.8 km / s ( 1000 m / 1 km ) ( 1 mile / 1609 meters ) ( 3600 s / 1 hr ) ( 24 hr / 1 day ) ( 365 days / 1 year ) = 74479055.3 miles per year
Answer:
The voltage is 
Explanation:
Generally the half reaction for Zn, Zn2 half-cell is mathematically represented as
⇔
(reference study academy)
and the electric potential for this is a constant value

Generally the half reaction for Al, Al3 half-cell is mathematically represented as
⇔ 
and the electric potential for this is constant value

Therefore the cell potential for an electrochemical cell is mathematically represented as

substituting values


C4H10 is an alkane (propane to be precise)
The relative formula mass of a molecule of propane is
(12x4) + (1x10) = 58
because a carbon atom has an atomic weight of 12 and a hydrogen atom has an atomic weight of 1.