First, find the volume the solution needs to be diluted to in order to have the desired molarity:
You have to use the equation M₁V₁=M₂V₂ when ever dealing with dilutions.
M₁=the starting concentration of the solution (in this case 2.6M)
V₁=the starting volume of the solution (in this case 0.035L)
M₂=the concentration we want to dilute to (in this case 1.2M)
V₂=the volume of solution needed for the dilution (not given)
Explaining the reasoning behind the above equation:
MV=moles of solute (in this case KCl) because molarity is the moles of solute per Liter of solution so by multiplying the molarity by the volume you are left with the moles of solute. The moles of solute is a constant since by adding solvent (in this case water) the amount of solute does not change. That means that M₁V₁=moles of solute=M₂V₂ and that relationship will always be true in any dilution.
Solving for the above equation:
V₂=M₁V₁/M₂
V₂=(2.6M×0.035L)/1.2M
V₂=0.0758 L
That means that the solution needs to be diluted to 75.8mL to have a final concentration of 1.2M.
Second, Finding the amount of water needed to be added:
Since we know that the volume of the solution was originally 35mL and needed to be diluted to 75.8mL to reach the desired molarity, to find the amount of solvent needed to be added all you do is V₂-V₁ since the difference in the starting volume and final volume is equal to the volume of solvent added.
75.8mL-35mL=40.8mL
40.8mL of water needs to be added
I hope this helps. Let me know if anything is unclear.
Good luck on your quiz!
The first person to organize the periodic table was chemist Dimitri Mendeleiv. He ordered the elements by mass number and organized them in columns and rows. These columns and rows shared similar characteristics both fisical and chemical. Back then there were only 60 or so discovered elements of the 118 that exist today. Mendeleiv left some blank spaces in between elements, predicting that future scientists would find elements to fill this spaces and these would have similar characteristics as the one around it. both of these predictions were right. However, he admitted that his method or organization may be wrong for he could have calculated the mass number incorrectly. Then another scientist named Henry Moseley found that he could reorganize the table by the atomic number and still be able to group elements by their characteristics.
I hope that answers your question!
Answer: Oxidation reaction occurs when a reactant losses electrons in the reaction.
Reduction reaction occurs when a reactant gains electrons in the reaction.
Explanation: Reduction reaction : It is defined as the reaction in which a substance gains electrons. That means, the gain of electrons takes place.
Or we can say that, reduction reaction occurs when a reactant gains electrons in the reaction.
Redox reaction or Oxidation-reduction reaction : It is defined as the reaction in which the oxidation and reduction reaction takes place simultaneously.