Answer:
10.76 grams
Explanation:
Given that the amount of 
is 25.0 grams.
Mass of 1 mole of = 158 grams
The number of atoms in 1 mole of is 4.
Mass of oxygen in 1 mole of = 16\times 4 = 68 grams.
Here, 158 grams of has 68 grams of oxygen
So, the amount of oxygen in 1 gram of = 68/158 grams
Therefore, the amount of oxygen in 1 gram of = 
grams
=10.76 grams
Hence, 25 grams of has 10.76 grams of oxygen.
Answer:
K = 2.7x10⁻⁵ at 25ºC
Explanation:
A way to write Arrhenius equation is:
ln K = - Ea/R × (1/T) + lnA
If you graph ln K as Y and 1/T as X (Absolute temperature in K), the equation you will obtain is:
Y = -13815X +35.817
R² = 0.9927
(Taking the last k point as 0.0386) (ln 0.0386), <em>0.1386 has no sense</em>)
Your slope is -13815
-13815K = - Ea/R
-13815K×8.314J/molK = 114858J/mol = Ea
And your intercept =
lnA = 35.817
A = 3.59x10¹⁵
Now, you want to know rate constant at 25ºC = 298.15K. Replacing in the equation (Where Y is ln (activation energy) and X is 1/T):
Y = -13815X +35.817
Y = -13815(1/298.15K) +35.817
Y = -10.5187
lnK = -10.5187
<h3>K = 2.7x10⁻⁵ at 25ºC</h3>
Copper is a good conductor of heat and electricity so it will not fry easily
