1. Molarity : 0.25 M
2. mol CH₄ = 7.4 moles
mol O₂ = 14.8 moles
<h3>Further explanation</h3>
1.
Given
83.2 g CuCl2 in 2.5 liters of water
Required
the molarity
Solution
Molarity : mol solute per liter of solution(not per liter of solvent)
mol solute = mol CuCl₂
mol CuCl₂ = mass : MW CuCl₂
mol CuCl₂ = 83.2 : 134.45
mol CuCl₂ = 0.619
Molarity(M) = mol : V
Assume density CuCl₂ = 3.39 g/cm³
volume CuCl₂ = 8.32 g : 3.39 g/cm³ = 2.45 cm³=2.45 x 10⁻³ L
With this small volume value of CuCl₂, the volume of the solute is sometimes neglected in calculating molarity
volume of solution = 2.5 L + 2.45 x 10⁻³ L = 2.50245 L
Molarity(M) = mol : V
M = 0.619 : 2.50245 L = 0.247≈0.25
2.
Given
Reaction
The correct balanced reaction:
CH4 + 2O2 → CO2 + 2H2O
7.4 moles CO2
Required
moles of methane (CH4) and oxygen gas (O2)
Solution
From the equation, mol ratio of CO₂ : CH₄ : O₂ = 1 : 1 : 2
mol CH₄ = mol CO₂ = 7.4 moles
mol O₂ = 2 x mol CO₂ = 2 x 7.4 moles = 14.8 moles
INFORMATION:
Is given that:
- if you have a block of plastic and a block of copper that are the same mass and are placed in the sun for 10 minutes.
And after the 10 minutes copper has a higher temperature.
We must determine the reason.
STEP BY STEP EXPLANATION:
To determine it, we need to know the concept of specific heat
If the block of copper has a higher temperature after 10 minutes, that means copper needs less heat to raise its temperature.
So, plastic has a higher specific heat than metal, so it takes more energy to heat plastic than copper. As a result, plastic would heat up more slowly.
ANSWER:
The explanation for the copper having a higher temperature after 10 minutes in the sun, is that plastic has a higher specific heat than metal, so it takes more energy to heat plastic than copper. As a result, plastic would heat up more slowly. Since the copper has a lower specific heat, it will be heat quickly.
The valence electrons of an element is usually determined by its atomic number. The valence elctrons are the electrons that have the highest energy level.
Fluorine has 7 valence electrons in the ground state.
Endothermic- endothermal, heat absorbing
Ectothermic- exothermal exoergic energy releasing, heat releasing
