Heat required : 4.8 kJ
<h3>Further explanation
</h3>
The heat to change the phase can be formulated :
Q = mLf (melting/freezing)
Q = mLv (vaporization/condensation)
Lf=latent heat of fusion
Lv=latent heat of vaporization
The heat needed to raise the temperature
Q = m . c . Δt
1. heat to raise temperature from -20 °C to 0 °C

2. phase change(ice to water)

3. heat to raise temperature from 0 °C to 25 °C


Neither it's a single replacement equation
NaCl consists of a salt, which is a nonmetal (Na) and Cl, which is a metal. When a nonmetal and a metal are combined, it makes the compound ionic.
Answer:
Distance, direction and symbol.
Explanation:
Distance, direction and symbol are the three components of the map which make a complete description of a location. On the map, these three components are present which provides information about a specific location on the map. Map is a drawing on the paper that shows the geography of the whole world and provides information in detail.
Considering the ideal gas law, a sample weighing 9.49 g occupies 68.67 L at 353 K and 2.00 atm.
Ideal gases are a simplification of real gases that is done to study them more easily. It is considered to be formed by point particles, do not interact with each other and move randomly. It is also considered that the molecules of an ideal gas, in themselves, do not occupy any volume.
An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P× V = n× R× T
In this case, you know:
- P= 2 atm
- V= ?
- n=
being 2g/mole the molar mass of H2, that is, the amount of mass that a substance contains in one mole. - R= 0.082

- T= 353 K
Replacing:
2 atm× V = 4.745 moles× 0.082
× 353 K
Solving:
V = (4.745 moles× 0.082
× 353 K)÷ 2 atm
<u><em>V= 68.67 L</em></u>
Finally, a sample weighing 9.49 g occupies 68.67 L at 353 K and 2.00 atm.
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