Answer:
physical
Explanation:
The zinc (which was already silver) coated the penny. The NaOH dissolved the zinc. (that was what made the water murky) And small pieces of zinc adhered to the penny (coated) It was a physical change because no NEW color was created.
Answer: The initial partial pressures of and is 139.4 torr.
Explanation:
The equilibrium reaction is
initially conc. p p 0
At eqm. p-2x p-x 2x
Given:
The expression for equilibrium constant is :
= 2x =115 torr
= (p-2x) = p-115 torr
= (p-x)= p-57.5 torr
Now put all the given values in this expression, we get
Therefore, the initial partial pressures of and is 139.4 torr.
Answer:
Model A
Explanation:
Model A represents an atom that is more reactive than the others represented.
Valence electrons actually determine the reactivity of elements. They also determine the properties of elements.
Elements with one valence electron are highly reactive because they need low energy to remove them. They can either gain more electrons to become stable or they share/give out their electrons.
Therefore, Model A is the correct answer because it has one valence electron and its valence electron is farther from the nucleus thereby this makes it more reactive.
Answer:
What are you doing stepbro?
Explanation:
Answer:
w = -531 kJ
1. Work was done by the system.
Explanation:
Step 1: Given data
- Heat gained by the system (q): 687 kJ (By convention, when the system absorbs heat, q > 0).
- Change in the internal energy of the system (ΔU°): 156 kJ
Step 2: Calculate the work done (w)
We will use the following expression.
ΔU° = q + w
w = ΔU° - q
w = 156 kJ - 687 kJ
w = -531 kJ
By convention, when w < 0, work is done by the system on the surroundings.