Answer:
The molar concentration of Cu²⁺ in the initial solution is 6.964x10⁻⁴ M.
Explanation:
The first step to solving this problem is calculating the number of moles of Cu(NO₃)₂ added to the solution:
n = 1.375x10⁻⁵ mol
The second step is relating the number of moles to the signal. We know the the n calculated before is equivalent to a signal increase of 19.9 units (45.1-25.2):
1.375x10⁻⁵ mol _________ 19.9 units
x _________ 25.2 units
x = 1.741x10⁻⁵mol
Finally, we can calculate the Cu²⁺ concentration :
C = 1.741x10⁻⁵mol / 0.025 L
C = 6.964x10⁻⁴ M
There are 30 protons and 39 neutrons in the nucleus.
This must me the isotope of an element with an atomic mass close to 69 u.
The only candidates are Zn and Ga.
Zn has a zinc-69 isotope with mass 68.926 u.
Ga has a gallium -69 isotope with mass 68.925 u.
The isotope is probably
.
It has 30 protons and 39 neutrons.
That is only the combustion of a hydrocarbon. Rust is a combustion reaction because oxygen is added.
Fe(s) + O2(g) => FeO2(s)
<u>Answer:</u> The reaction proceeds in the forward direction
<u>Explanation:</u>
For the given chemical equation:
Relation of 
is given by the formula:
where,
= equilibrium constant in terms of partial pressure = ?
= equilibrium constant in terms of concentration = 
R = Gas constant = 
T = temperature = ![35^oC=[35+273]K=308K](https://tex.z-dn.net/?f=35%5EoC%3D%5B35%2B273%5DK%3D308K)
= change in number of moles of gas particles = 
Putting values in above equation, we get:
is the constant of a certain reaction at equilibrium while 
is the quotient of activities of products and reactants at any stage other than equilibrium of a reaction.
The expression of for above equation follows:
We are given:
Putting values in above equation, we get:
We are given:
There are 3 conditions:
- When
; the reaction is product favored. - When
; the reaction is reactant favored. - When
; the reaction is in equilibrium
As, 
, the reaction will be favoring product side.
Hence, the reaction proceeds in the forward direction
