Answer:
A pure solid is heated and turns into a pure liquid.
Explanation:
No colour change recorded, only change of state, hence this is a physical change - physical changes I.e. change of state and temperature are not chemical reactions.
Answer:
- <em>The partial pressure of oxygen in the mixture is</em><u> 320.0 mm Hg</u>
Explanation:
<u>1) Take a base of 100 liters of mixture</u>:
- N: 60% × 100 liter = 60 liter
- O: 40 % × 100 liter = 40 liter.
<u>2) Volume fraction:</u>
At constant pressure and temperature, the volume of a gas is proportional to the number of molecules.
Then, the mole ratio is equal to the volume ratio. Callin n₁ and n₂, the number of moles of nitrogen and oxygen, respectively, and V₁, V₂ the volume of the respective gases you can set the proportion:
That means that the mole ratio is equal to the volume ratio, and the mole fraction is equal to the volume fraction.
Then, since the law of partial pressures of gases states that the partial pressure of each gas is equal to the mole fraction of the gas multiplied by the total pressure, you can draw the conclusion that the partial pressure of each gas is equal to the volume fraction of the gas in the mixture multiplied by the total pressure.
Then calculate the volume fractions:
- Volume fraction of a gas = volume of the gas / volume of the mixture
- N: 60 liter / 100 liter = 0.6 liter
- V: 40 liter / 100 liter = 0.4 liter
<u>3) Partial pressures:</u>
These are the final calculations and results:
- Partial pressure = volume fraction × total pressure
- Partial pressure of N = 0.6 × 800.0 mm Hg = 480.0 mm Hg
- Partial pressure of O = 0.4 × 800.0 mm Hg = 320.0 mm Hg
Answer:
The range of [H⁺] is from 2.51 x 10⁻⁶ M to 6.31 x 10⁻⁶ M,
Explanation:
To answer this problem we need to keep in mind the <u>definition of pH</u>:
So now we <u>calculate [H⁺] using a pH value of 5.2 and of 5.6</u>:
-5.2 = log [H⁺]
= [H⁺]
6.31 x 10⁻⁶ M = [H⁺]
-5.6 = log [H⁺]
= [H⁺]
2.51 x 10⁻⁶ M = [H⁺]
Answer:
The first one is B, "Decreasing surface area."
Explanation:
This is because greater the surface area exposed, the more collisions that occur between the solvent and solute. I also just took the test myself and got it correct.
Answer:
Oxygen comes 8th on the periodic table which is the atomic number.
Explanation:
but Oxygen 13 (Isotopes of Oxygen) is when oxygen has 8 protons and electrons, and 5 neutrons (8+5=13)
