Answer:
No one is correct. The correct expression is:
Keq = [H₂]² . [O₂]² / [H₂O]²
Explanation:
To build the Keq expression in a chemical equilibrium you must consider the molar concentrations of reactants / products, and they must be elevated to the stoichiometric coefficient.
The balance reaction is:
<u>2</u> H₂O (g) ⇄ <u>2</u> H₂ (g) + O₂ (g)
Keq = [H₂]² . [O₂] / [H₂O]²
In opposite side: <u>2</u> H₂ (g) + O₂ (g) ⇄ <u>2</u> H₂O (g)
Keq = [H₂O]² / [H₂]² . [O₂]
To find this, we will use this formula:
Molar mass of element
------------------------------------ x 100
Molar mass of compound
So, first lets calculate the mass of the compound as a whole. We use the atomic masses on the periodic table to determine this.
Ca: 40.078 g/mol
N2 (there is two nitrogens): 28.014 g/mol
O6 (there are six nitrogens: 3 times 2): 95.994 g/mol
When we add all of those numbers up together, we get 164.086. That is the molar mass for the whole compound. However, we are trying to figure out what percent of the compound oxygen makes up. From the molar mass, we know that 95.994 of the 164.086 is oxygen. Lets plug those numbers into our equation!
95.994
-----------
164.086
When we divide those two numbers, we get .585. When we multiply that by 100, we get 58.5.
So, the percent compostition of oxygen in Ca(NO3)2, or, calcium nitrate, is 58.5%.
Answer:
On the outside or something like that
Answer:
19 °C
Explanation:
Step 1: Given and required data
- Mass of granite (m): 20 g
- Heat absorbed (Q): 300. 2 J
- Specific heat capacity of granite (c): 0.790 J/g.°C
Step 2: Calculate the temperature change (ΔT)
We will use the following expression.
Q = c × m × ΔT
ΔT = Q/c × m
ΔT = 300.2 J/(0.790 J/g.°C) × 20 g = 19 °C
Answer:
The accepted views of science knowledge can change over time. Changes can result from new science observations, but can also be affected by social, political or religious convictions. To develop a deeper understanding, students need to investigate the context of the time in which science ideas were developed.
Explanation:
