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.
The volume of 0. 250 mole sample of 
gas occupy if it had a pressure of 1. 70 atm and a temperature of 35 °C is 3.71 L.
Calculation,
According to ideal gas equation which is known as ideal gas law,
PV =n RT
- P is the pressure of the hydrogen gas = 1.7 atm
- Vis the volume of the hydrogen gas = ?
- n is the number of the hydrogen gas = 0.25 mole
- R is the universal gas constant = 0.082 atm L/mole K
- T is the temperature of the sample = 35°C = 35 + 273 = 308 K
By putting all the values of the given data like pressure temperature universal gas constant and number of moles in equation (i) we get ,
1.7 atm×V = 0.25 mole ×0.082 × 208 K
V = 0.25 mole ×0.082atm L /mole K × 308 K /1.7 atm
V = 3.71 L
So, volume of the sample of the hydrogen gas occupy is 3.71 L.
learn more about ideal gas equation
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doesnt salt desolve ice? so wouldn't the salt dissolve in the ice water?
Answer : Option A) The direction the wire moves in
and Option C) the direction of the magnetic field.
Explanation : The direction of current flowing through the wire mainly depens on two factors which are i) direction of the wire moves in and ii) the direction of magnetic field.
The flow of current will occur in the direction of the wire through which it is moving in, whereas the direction of magnetic field will be in concentric circles around the direction of current passing through the wire.
