Answer : The mass of helium gas in the balloon is, 1.23 grams.
Explanation : Given,
Volume of helium gas = 6.9 L
First we have to calculate moles of helium gas at STP.
As we know that, 1 mole of substance occupy 22.4 L volume of gas.
As, 22.4 L volume of helium gas present in 1 mole of helium
So, 6.9 L volume of helium gas present in 
of helium
Now we have to calculate the mass of helium gas.
Molar mass of He gas = 4 g/mol
Thus, the mass of helium gas in the balloon is, 1.23 grams.
Answer:
- A) pH = 2.42
- B) pH = 12.00
Explanation:
<em>The dissolution of HCl is HCl → H⁺ + Cl⁻</em>
- To solve part A) we need to calculate the concentration of H⁺, to do that we need the moles of H⁺ and the volume.
The problem gives us V=2.5 L, and the moles can be calculated using the molecular weight of HCl, 36.46 g/mol:
= 9.60*10⁻³ mol H⁺
So the concentration of H⁺ is
[H⁺] = 9.60*10⁻³ mol / 2.5 L = 3.84 * 10⁻³ M
pH = -log [H⁺] = -log (3.84 * 10⁻³) = 2.42
- <em>The dissolution of NaOH is NaOH → Na⁺ + OH⁻</em>
- Now we calculate [OH⁻], we already know that V = 2.0 L, and a similar process is used to calculate the moles of OH⁻, keeping in mind the molecular weight of NaOH, 40 g/mol:
= 0.02 mol OH⁻
[OH⁻] = 0.02 mol / 2.0 L = 0.01
pOH = -log [OH⁻] = -log (0.01) = 2.00
With the pOH, we can calculate the pH:
pH + pOH = 14.00
pH + 2.00 = 14.00
pH = 12.00
In a sample of H2SO4 that contain 200 S atom the number of hydrogen atoms would be 400 atoms
explanation
there are two moles of H2 in H2SO4 therefore by use of ratio between S:H2 which is 1:2 atoms therefore the atoms of hydrogen = 2 x200 = 400 atoms
According to Kinetic molecular theory, the frozen balloon shrank and it will expands and get burst when it is kept in sun.
<h3>What is Kinetic molecular theory ?</h3>
Kinetic molecular theory of gases is a theoretical model that describes the molecular composition of the gas in terms of a large number of submicroscopic particles which include atoms and molecules.
According to this theory, gas pressure arises due to particles colliding with each other and the walls of the container.
Because the average kinetic energy of the gas molecules in a balloon decreases when the temperature decreases.
This makes the molecules move more slowly and have less frequent and weaker collisions with the inside wall of the balloon, which causes the balloon to shrink a little.
Due to the sun's heat, the kinetic energy of particles in the balloon increases and it expands and continues to expand and comes to a stage when the balloon bursts.
Therefore,
According to Kinetic molecular theory, the frozen balloon shrank and it will expands and get burst when it is kept in sun.
Learn more about kinetic theory here ;
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