✅Show work regardless if student got answer correct or incorrect
q = mC∆T
q = (30.0g)(0.900J/goC)(50oC)
q = 1350 J
So, the right answer is 1350 J
IamSugarBee◽
The element having valency of 1 is ~
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!
13
Al
Aluminum
Atomic mass 26.982
Answer: ³²P
Explanation:
The radionuclide in question is known as Phosphorus-32. It is an isotope of Phosphorus that is radioactive and has one more neutron than the normal phosphorus does.
Phosphorus does not exist in nature and is created artificially by bombarding the normal stable phosphorus with neutrons. Due to its radioactive nature, it has proven to be useful in the medical industry where it has been used to detect eye tumors as well as in treating some diseases.
