Answer: burning paper
Explanation:
The paper burns in air to form smoke and ash. which makes it a chemical change.
I would say when an atom has its valence electron shell filled like a noble gas has, it is not easily changed.
I’m not entirely sure of what you’re asking, but if you’re talking about bonding then it would be an ionic bond that is not easily changed.
Answer:
4.13 moles of Fe
Explanation:
Step 1: Write the balanced equation
3 CO + Fe₂O₃ ⇒ 2 Fe + 3 CO₂
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of CO to Fe is 3:2.
Step 3: Calculate the moles of Fe formed from 6.20 moles of CO
We will use the previously established molar ratio.
6.20 mol CO × 2 mol Fe/3 mol CO = 4.13 mol Fe
You must know and use the formula for pH.
pH = - log [H3O+], where [H3O+] is the molar concentration of hydronium ion.
So, when pH is 8.0 => 8.0 = - log [H3O+] and you can use antilogarithm (the inverse function of logarithm) to find [H3O+], in this way:
[H3O+] = 10^-8 = 1 * 10 ^-8 M
When, pH = 7.0 =>
7.0 = - log [H3O+] => [H3O+] = 1 * 10^ -7 M
Answer: 1*10^-7 mole / liter
