A and B can react to form C and D or, in the reverse reaction, C and D can react to form A and B. This is distinct from reversible process in thermodynamics.
Weak acids and bases undertake reversible reactions. For example, carbonic acid: H2CO3 (l) + H2O(l) ⇌ HCO−3 (aq) + H3O+(aq).
The concentrations of reactants and products in an equilibrium mixture are determined by the analytical concentrations of the reagents (A and B or C and D) and the equilibrium constant, K. The magnitude of the equilibrium constant depends on the Gibbs free energy change for the reaction.[2] So, when the free energy change is large (more than about 30 kJ mol−1), then the equilibrium constant is large (log K > 3) and the concentrations of the reactants at equilibrium are very small. Such a reaction is sometimes considered to be an irreversible reaction, although in reality small amounts of the reactants are still expected to be present in the reacting system. A truly irreversible chemical reaction is usually achieved when one of the products exits the reacting system, for example, as does carbon dioxide (volatile) in the reaction
Answer:
An experiment where an antibiotic is tested against bacteria. The antibiotic can vary in its concentration for example, different amounts are applied to a sample of bacteria to see if it is affected by the action of the antibiotic and if so, in what concentration. So, the independent variable is the concentration of antibiotic while the dependent variable is the survival (or not) of the bacteria.
Explanation:
An independent variable is a variable that represents a quantity that the scientist modifies in an experiment. A dependent variable represents a quantity whose value depends on how the independent variable is modified. This is the variable being studied and measured.
So, an example of this applied to bacteria or viruses could be:
<u>An experiment where an antibiotic is tested against bacteria</u>. The antibiotic can vary in its concentration, different amounts are applied to a sample of bacteria to see if it is affected by the action of the antibiotic and if so, in what concentration. So, the independent variable is the concentration of antibiotic while the dependent variable is the survival (or not) of the bacteria.
To complete the experiment, an antibiotic whose effect is already known can be used as a positive control. That is, it is already known to kill the bacteria. And as a negative control you can simply use water, which has no effect and is known not to kill the bacteria. In this way, we validate the results and make sure that there is not something else that is affecting the bacteria and that only the antibiotic being studied has an influence.
Answer:
True
Explanation:
Physical contamination are foreign objects such as hair, fingernails, broken glasses , jewelries etc that are mixed with food. Although, it is important for a food handler who realizes that he is sick such as having fever, jaundice,wound while working to report such to his supervisor or manager,who will then take necessary action and to avoid risk of contamination; yet not the only cause of physical food contamination.
Physical contamination does not necessarily have to occur until the food handler is sick. It could be as a result of carelessness or not paying attention enough by the food handler . Physical contamination might not at all times cause injury or illness to the customer, yet such could bring discomfort to a customer who notices foreign objects in his food while eating. To avoid risk of physical food contamination, it is important for food handlers to keep jewelries to a minimum, wash fruits and vegetables thoroughly, wear hear neatly tied back, throw out and replace cracked, chipped, or broken dishware, glassware and equipment amongst others.
Adaptations help the survival of a species as "It increases the biodiversity of the species".
<u>Answer:</u> Option C
<u>Explanation:</u>
The phenomenon that support the organisms to find similar and favourable environment to acquire food, build home, satisfy with weather, feel safe and attract mates to produce more offspring in order to improve evolutionary fitness is called as an "Adaptation".
The three main forms of adaptations are behavioural, structural, and physiological adaptations that are based on the way how genetic variation get communicated. Many species have all those types of combinations. For an instance, behavioural adaptations are bird's calling and migration.
