Physical changes<span> are </span>changes<span> affecting the form of a chemical </span>substance<span>, but not its chemical composition. </span>Physical changes<span> are used to separate mixtures into their component compounds, but </span>can<span> not usually be used to separate compounds into chemical elements or simpler compounds.</span>
Answer:
2360J
Explanation:
Given parameters:
Mass of aluminum = 25g
Melting point = 658°C
Latent heat of melting = 94.4j/g
Unknown:
Amount of heat require for melting = ?
Solution:
The amount of heat required for this melting will be the product of the mass of the aluminum and the latent heat of melting;
H = m L
m is the mass
L is the latent heat of melting
Insert the parameters and solve;
H = 25 x 94.4 = 2360J
When,
[OH⁻] = 1.4 × 10⁻³
Then,
pOH = -log (1.4 × 10⁻³)
pOH = 2.85
Also,
pH + pOH = 14
So,
pH = 14 - 2.85
pH = 11.15
As pH is greater than 7, so the solution is Basic in Nature.
Calculating for concentration of [H⁺],
As,
pH = -log [H⁺]
Or,
11.15 = -log [H⁺]
Taking Antilog on both sides,
[H⁺] = 7.07 × 10⁻¹² M
Result:
A solution with a hydroxide ion concentration of 4.15 × 10⁻³<span> M is Basic and has a hydrogen ion concentration of </span><u>7.07 × 10⁻¹² M.</u>