A non-chlorine chemical such as iodine may be used as a
sanitizing solution. To use iodine as a sanitizing solution, it should be
around 12.5-25 ppm in water that is at least 75° F. Utensils and equipment must
be immersed for only 30 seconds because it may lose its effectivity if the pH
level gets too high due to high temperature. Discoloration may also result if
the utensils and equipment are in prolonged contact with the solution.
Since you didn't have any extra information about the question I'll be presenting an example from my own textbooks that I've used.
An example of a direct observation is listening to a cricket chirp at night, and counting the number of chirps per minute.
Direct Observation is where the evaulator watches the subject in their usual habitat without disrupting or altering it.
Answer:
5 moles of oxygen are required.
Explanation:
Given data:
Moles of O₂ required = ?
Moles of H₂ present = 10 mol
Solution:
Chemical equation:
O₂ + 2H₂ → 2H₂O
Now we will compare the moles of oxygen and hydrogen.
H₂ : O₂
2 : 1
10 : 1/2×10 = 5 mol
5 moles of oxygen are required.
Answer:
The molar mass of the gas is 36.25 g/mol.
Explanation:
- To solve this problem, we can use the mathematical relation:
ν = 
Where, ν is the speed of light in a gas <em>(ν = 449 m/s)</em>,
R is the universal gas constant <em>(R = 8.314 J/mol.K)</em>,
T is the temperature of the gas in Kelvin <em>(T = 20 °C + 273 = 293 K)</em>,
M is the molar mass of the gas in <em>(Kg/mol)</em>.
ν =
(449 m/s) = √ (3(8.314 J/mol.K) (293 K) / M,
<em>by squaring the two sides:</em>
(449 m/s)² = (3 (8.314 J/mol.K) (293 K)) / M,
∴ M = (3 (8.314 J/mol.K) (293 K) / (449 m/s)² = 7308.006 / 201601 = 0.03625 Kg/mol.
<em>∴ The molar mass of the gas is 36.25 g/mol.</em>
