Explanation:
A mixture in which there is uniform distribution of solute particles into the solvent is known as a homogeneous mixture.
For example, sugar dissolved in water is a homogeneous mixture.
On the other hand, a mixture in which there is uneven distribution of solute particles into the solvent is known as a heterogeneous mixture.
For example, sand present in water is a heterogeneous mixture.
Comment on given situations will be as follows.
(a) Air in a closed bottle - It is a homogeneous mixture because there will be even distribution of other gases that are present in air.
(b) Air over New York City - It is a heterogeneous mixture because there will be presence of some dust particles, fog or smoke into the air. Distribution of all these particles will be uneven. This will make air over New York City heterogeneous in nature.
8 tablets. To get 1 gram you would have to give 2 tablets every 6 hours. In 24 hours you would give 8 tablets (500 mg = .5 grams)
Answer:
This relationship between temperature and pressure is observed for any sample of gas confined to a constant volume. If the temperature increases by a certain factor, the gas pressure increases by the same factor.
Answer: Correct option is (D).
Explanation:
Given that unknown element has larger atomic radii than potassium atoms and its valence electrons feel an effective nuclear charge of +1 which means that this unknown element belongs to group(I) of the periodic table.
In periodic table:
- As we move down the group the value of ionization energy decreases down the group. This is due to increase in the size of an element.With increase in size valence electrons gets far away from the nucleus by which less energy will require to ionize the element.
- Electronegative characters also decreases when we move down the group.This is due to increase in size of an element by which electrons present in valence shells are far away from the nucleus.
So,It would have lower ionization energies than K and a lower electronegativity value than K.
Answer:
[KOH] = 7.76×10⁻³ M
[Ca(OH)₂] = 2.39×10⁻³ M
Explanation:
KOH → K⁺ + OH⁻
pH = - log [H⁺]
14 = pH + pOH
pOH = - log [OH⁻]
10^-pOH = [OH⁻]
14 - 11.89 = 2.11 → pOH
2.11 = - log [OH⁻]
10⁻²°¹¹ = [OH⁻] → 7.76×10⁻³ M
As ratio is 1:1, [KOH] = 7.76×10⁻³ M
14 - 11.68 = 2.32 → pOH
10⁻²°³² = [OH⁻] → 4.78×10⁻³ M
Ca(OH)₂ → Ca²⁺ + 2OH⁻
Ratio is 2:1, so I will have the half of base.
4.78×10⁻³ /2 = 2.39×10⁻³ M
