Answer:
Magnesium
Zinc
Iron
Copper
Explanation:
The given elements are:
Magnesium, copper, iron and zinc
We are to put them in the order from the least reactive to the most reactive of all.
To solve this problem, we simply use the activity series of metals to arrange the elements.
The activity series arranges metals from the most reactive to the least reactive. The more reactive metals displaces the lesser one from solutions.
So;
Magnesium
Zinc
Iron
Copper
The concentration of solution : 0.2 M
<h3>
Further explanation
</h3>
Given
5.6 g Potassium hydroxide(KOH)
500 ml of solution = 0.5 L
Required
The concentration
Solution
Molarity shows the number of moles of solute in every 1 liter of solution or mmol in each ml of solution
MW KOH = 39+16+1=56 g/mol
mol solute(KOH) :
= mass : MW KOH
= 5.6 : 56 g/mol
= 0.1
Molarity :
= 0.1 : 0.5
= 0.2 M
Compare the density of the object in question to the density of water. If its density is less than water, it will float. For example, oak floats because its density is 0.7 g/cm³. If the density of an object is greater than water, it will sink.