Answer:
0.51M
Explanation:
Given parameters:
Initial volume of NaBr = 340mL
Initial molarity = 1.5M
Final volume = 1000mL
Unknown:
Final molarity = ?
Solution;
This is a dilution problem whereas the concentration of a compound changes from one to another.
In this kind of problem, we must establish that the number of moles still remains the same.
number of moles initially before diluting = number of moles after dilution
Number of moles = Molarity x volume
Let us find the number of moles;
Number of moles = initial volume x initial molarity
Convert mL to dm³;
1000mL = 1dm³
340mL gives 
= 0.34dm³
Number of moles = initial volume x initial molarity = 0.34 x 1.5 = 0.51moles
Now to find the new molarity/concentration;
Final molarity = 
= 
= 0.51M
We can see a massive drop in molarity this is due to dilution of the initial concentration.
Their locations can vary depending on the molecule they are associated with but they are usually in a "cloud " that is on the outside of an atom/molecule and if the atom is unstable the electrons tend to be located farther away from the atom.
Answer: A. Limestone rocks dissolving in water
Explanation:
B: This is a physical change; it changes an object physically rather than chemically. It does not change the composition of the concrete, only the shape.
C: This is also a physical change because the water is just dragging sand with it, but not actually changing the composition of it.
D: Similar to option B, this is an example of physical weathering because the ice only divides the rock into different parts but doesn't change the composition or complexity of it.
The subatomic particle that gives off visible light is electrons
Answer:
a) ΔGº= -49,9 KJ/mol = - 50 KJ/mol
b) The reaction goes to the right to formation of products
c) ΔG= 84,42 KJ/mol. The direction is to reactive, to the left
Explanation:
a) ΔGº= - RTLnKf
You need to convert Cº to K. 25ºC=298K
Then, ΔGº= - 3,814 J/molK * 298K* Ln(5.6 *10^8)= - 49906 J/mol = -49,9 KJ/mol = - 50 KJ/mol
b) The ΔGº < 0, that means the direct reaction is spontaneous when te reactive and products are in standard state. In other words the reaction goes to the right, to formation of products
c) The general ecuation for chemical reaction is aA + bB → cD + dD. Thus
ΔG=ΔGº + RTLn (([C]^c*[D]^d)/[A]^a*[B]^b)
In this case,
ΔG=ΔGº + RTLn ([Ni(NH3)62+] / [Ni2+]*[NH3]^6 )= 84417 J/mol =84,42 KJ/mol
ΔG >0 means the reaction isn't spontaneous in the direction of the products. Therefore the direction is to reactive, to the left
