The question is incomplete, here is the complete question:
Write a balanced chemical equation for each single replacement reaction that takes place in aqueous solution. write no reaction if a reaction does not occur
1.) Zn + PbCl₂
2.) Cu + Fe(NO₃)₂
<u>Answer:</u>
<u>For 1:</u> The reaction does occur.
<u>For 2:</u> The reaction does not occur.
<u>Explanation:</u>
Single displacement reaction is defined as the reaction in which more reactive element displaces a less reactive element.
The reactivity of metal is determined by a series known as reactivity series. The metals lying above in the series are more reactive than the metals which lie below in the series.

For the given options:
Zinc is more reactive than lead as it lies above in the series. So, it will displace lead from its chemical equation.
The chemical equation for the reaction of zinc and lead chloride follows:

Copper is less reactive than iron as it lies below in the series. So, it will not displace iron from its chemical equation.
The chemical equation for the reaction of copper and iron (II) nitrate follows:

Answer:
Kinetic energy decreases as temperature decreases.
Explanation:
From the description that the system at 80°C has longer arrows, or move faster than the system at 20°C, having shorter actors indicating a slower motion, we can conclude that the kinetic energy of a body depends on its temperature.
If the system at 80°C shows a greater kinetic energy (faster motion of particles) than the system at 20°C, it then implies that decreasing the temperature of the body decreases its kinetic energy.
Answer:27,430J/g.K
Explanation:q= mass* specific heat capacity * change in temperature (kelvin)
22*4.184*[(100-25) + 273]
22*4.184*298
27,430J/g.K