Answer: Decreases the rate of reaction
- Remove water from food by dehydration.
- Transport food in a refrigerated truck.
- Store food in airtight containers.
- Store food in a refrigerator after opening.
Does not decrease the rate of reaction
- Store food in the open air.
- Place food on a warm surface.
Explanation: Dehydration of food excludes water from food which is one of the factor needed by microorganisms for growth, <em>so it decreaese the rate of reaction.</em>
Transporting food in refrigerated trucks lowers the temperature of food and not many microorganisms are active at very low temperatures, so it <em>decreases the rate of reaction.</em>
Storing food in airtight containers excludes air which is one of the factors required for microbial activity, so <em>it decreases reaction rate.</em>
Storing food in refrigerators after opening also <em>lowers the temperature of food and hence the the rate of microbial activit</em>y.
Storing food in the open air <em>does not decrease microbial activity</em> instead it provides microorganisms with the favorable conditions for their activity such as air and water from water vapor in the air.
Placing food on a warm surface <em>does not decrease rate of reaction</em> because microorganisms are very active in warm and humid environments.
In given data:
maximum absorption wavelength λ = 580 nm = 580 x 10⁻⁹ m
write the equation to find the crystal field splitting energy:
E = hC / λ
Here, E is the crystal field splitting energy, h = 6.63 x 10⁻³⁴ J.sec is Planck's constant and C = 3 x 10⁸ m/sec is speed of light.
substitute in the equation above:
E = (6.64 x 10⁻³⁴ x 3 x 10⁸) / (580 x 10⁻⁹) = 3.43 x 10⁻¹⁹J
This crystal field splitting energy is for 1 ion.
Number of atoms in one mole, NA = 6.023 x 10²³
to calculate the crystal field splitting energy for one mole:
E(total) = E x NA
= (3.43 x 10⁻¹⁹) x (6.023 x 10²³) = 206 kJ/ mole
H h I ointment o on NB j. Non b kkkk NB nis o ok kno kno
Answer:
C. 0.04 moles per cubic decimeter.
Explanation:
The molar mass of the Iodine is 253.809 grams per mole and a cubic decimeter equals 1000 cubic centimeters. The concentration of Iodine (
), measured in moles per cubic decimeter, can be determined by the following formula:
(1)
Where:
- Mass of iodine, measured in grams.
- Molar mass of iodine, measured in grams per mol.
- Volume of solution, measured in cubic decimeters.
If we know that 
, 
and 
, then the concentration of iodine in a solution is:
Hence, the correct answer is C.
