Sand is usually hot from the sun. It is hot because of the sun. if the sand were to be wet then it would take longer to change.
Answer:
In cases where the water freezes, a release of energy occurs to the environment, therefore energy is lost, and it begins to "cool down".
The term cooling in chemical science today is not well seen since it is not considered that this exists, but would be replaced by the term "absence or loss of heat".
It is considered that a body cools when its temperature decreases, and if it continues to decrease as in the case of water, a point will reach the freezing point, which in this case that of water is 0 degrees Celsius, therefore when the cooling overcomes this thermal barrier the water solidifies "freezing"
Explanation:
In the case of pure water (H2O), the freezing point is 0 ° C. This means that, as long as it is at a temperature above 0ºC and below 100ºC (since that is its boiling point), the water will be in a liquid state.
It depends on the direction of the arrow.
If the arrow goes like this ---> the reactant would be 2Fe2O3
If the arrow goes like this <--- the reactants would be 4Fe + 3O2
Answer:
pH =6.70
Explanation:
When Kw = 1x10^-14
[H3O+] = [OH-] --> 1x10-7
Kw =3.98x^10-14
3.98x^10-14 = [H3O+] . [OH-]
√ (3.98x^10-14) = [H3O+] = [OH-]
[H3O+] = 1.99×10^-7
- log [H3O+] = pH ---> -log 1.99x10^-7 = 6.70
Answer:
The concentration of H3O+= 0.15M
Explanation:
From The equation of reaction
HClO2(aq) + H2O(l) ⇌ H3O+(aq) + ClO2−(aq)
0.25mol HClO2(aq) 0.25mol producesClO2−(aq) and x-mol of H3O+
Using Kc = [H3O+][ClO2-]/[HClO2]
0.15= 0.25*x/0.25
Simplify
x=0.15M
