Which of the following is displaced by 'Cu'? 1.Fe2+ 2.Ag+ 3.Zn2+ 4.Al3+

Explanation:

This problem tests our knowledge/understanding of the electro-chemical series.

Electrochemical series or activity series is a list that describes the arrangement of elements in order of their increasing electrode potential values.

In the electro-chemical series metals placed above can displace metals below from their salt solutions.

In this question given the series as  stated

1. Fe2+

2.Ag+

3.Zn2+

4.Al3+  

In the series we have metals stated as Zn>Fe>Cu>Ag.

Cu will displace silver Ag+  because it is below it in the series

rosa was looking for patterns to predict the products of chemical reactions. she recorded three similar decomposition reactions in the table.she should record 2licl + 3o2.

in the last row of the table. it is the thermal decomposition of chlorate lithium, hence, she should record these products as: lithium chloride ( 2licl ) and oxygen ( 3o2 )   2 > 2 licl + 3o2.