Is that chemistry?
Cause I'm kinda confused about how to help you with this question
Answer: The new volume is 53.3 ml
Explanation:
The combined gas equation is,
where,
= initial pressure of gas = 50.0 kPa
= final pressure of gas = 80.0 kPa
= initial volume of gas = 80.0 ml
= final volume of gas = ?
= initial temperature of gas =
= final temperature of gas =
Now put all the given values in the above equation, we get:
The new volume is 53.3 ml
Answer:
Hydroxy(oxo)bismuthine oxide
Answer: 4.18925 kJ heat is needed to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.
Explanation:
Temperature of Solid
Melting temperature of Solid 
Temperature of liquid 
Specific heats of solid ethanol = 0.97 J/gK
Specific heats of liquid ethanol = 2.3 J/gK
Heat required to melt the the 25 g solid
at 159 K
= 159 K - 138 K = 21 K

Heat required to melt and raise the temperature of
upto 223 K
= 223 K - 159 K = 64 K

Total heat to convert solid ethanol to liquid ethanol at given temperature :
(1kJ=1000J)
Hence, 4.18925 kJ of heat will be required to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.