MISC 03 - Finals Quiz Flashcards
The boundary between two phases is generally described as an interface (True or false)
True
For the majority of liquids, an increase in temperature leads to an increase in surface tension (True or false)
False (Increased temperature, decreased surface tension)
The interfacial tension between two immiscible liquids arises as a result of imbalance of forces, in an identical manner to the surface tension between a liquid and its vapor (True or false)
True
Spreading occurs when the liquid placed on, for example, a water surface adheres to the water more strongly than it coheres to itself (True or false)
True
An increase in the concentration of the solute will cause an increase in the amount of absorption that occurs at equilibrium until a limiting value is reached (True or false)
True
Adsorption is generally exothermic, and hence an increase in temperature leads to a decrease in adsorption (True or false)
True
An increased surface area, achieved by a reduction in particle size or the use of a porous material, will decrease the extent of adsorption (True or false)
False (Increased surface area, increased extent of adsorption)
The lower the HLB of an agent, the more hydrophobic it is (True or false)
True
The ability of the micelles to increase the solubility of materials that are normally insoluble, or only slightly soluble, in the dispersion medium is termed as solubility (True or false)
False (Solubilization)
A physically adsorbed gas can be desorbed from a solid by decreasing the temperature and increasing the pressure (True or false)
False (Increasing temperature, decreasing pressure)
The contact angle between a liquid and a solid may be 0° signifying incomplete wetting, or may approach 180°, at which wetting is complete (True or false)
False (0° signifies complete wetting)
As the concentration of electrolyte present in the system is increased, the degree of flocculation increases, while wetting decreases (True or false)
True
Carboxymethylcellulose, Carbopol 934, Veegum, Tragacanth, and Bentonite are examples of flocculating agents (True or false)
False (Suspending agents)
The velocity of sedimentation is expressed by Stoke’s law (True or false)
True
Caking commonly occurs in emulsion (True or false)
False (Suspensions)
The study of flow which addresses the viscosity characteristics of powders, fluids, and semisolids is micromeritics (True or false)
False (Rheology)
The relationship the rate depends on amounts of reactants is shown by reaction constant (True or false)
False (Rate law, not reaction constant)
The average rate of the reaction over each interval is the change in concentration divided by the change in time (True or false)
True
The average rate decreases as the reaction proceeds because as the reaction goes forward, there are fewer collisions between product molecules (True or false)
False (Reactant molecules)
At higher temperatures, reactant molecules have less kinetic energy, move faster, and collide more often and with greater energy (True or false)
False (More kinetic energy)
Half-life is defined as the time required for one-half of a reactant to react (True or false)
True
Rate constant is highly dependent on temperature (True or false)
True
The minimum amount of energy required for a reaction is called the activation energy (True or false)
True
Catalysts increase the rate of a reaction by increasing the activation energy of the reaction (True or false)
False (Decreasing activation energy)
The extent to which a product retains, within specified limits, and throughout its period of storage and use the same properties and characteristics that is possessed at the time of manufacture is the expiration date of the product (True or false)
False (Drug stability)
A shelf life of 2-3 years for a product is generally desired (True or false)
True
Association colloids are characterized by having two distinct regions of opposing solution affinities within the same molecule or ion (True or false)
True
Faraday-Tyndall effect is a kinetic property of colloids (True or false)
False (Optical property)
Streaming potential differs from sedimentation potential in that the potential is created by forcing a liquid to flow through a plug or bed of particles (True or false)
True
Emulsion is a colloid (True or false)
True
Viscoelasticity deals more on semi-solid dosage form (True or false)
True
Rotational viscometer is used to determine absolute or dynamic viscosity of a system (True or false)
False (Apparent)
As the temperature increases, the viscosity of a material also increases (True or false)
False (Viscosity decreases)
Syneresis occurs when the interaction between particles of the dispersed phase becomes so great that on standing, the dispersion medium is squeezed out in droplets and the gel shrinks (True or false)
True
Sedimentation rate decreases (Deflocculated or flocculated)
Deflocculated
Viscous (Deflocculated or flocculated)
Deflocculated
Aggregation of particles (Deflocculated or flocculated)
Flocculated
Weak van der Waal’s (Deflocculated or flocculated)
Flocculated
Clear supernatant (Deflocculated or flocculated)
Flocculated
Do not form a cake (Deflocculated or flocculated)
Deflocculated
Difficult to resuspend (Deflocculated or flocculated)
Deflocculated
Viscosity is independent of shear stress (Newtonian or non-Newtonian)
Newtonian
Milk tea (Newtonian or non-Newtonian)
Newtonian
Suspension (Newtonian or non-Newtonian)
Non-Newtonian
Syrup (Newtonian or non-Newtonian)
Newtonian
Oil (Newtonian or non-Newtonian)
Newtonian
Ointment (Newtonian or non-Newtonian)
Non-Newtonian
Ethyl alcohol (Newtonian or non-Newtonian)
Newtonian
Tomato ketchup (Newtonian or non-Newtonian)
Non-Newtonian
Whipped cream (Newtonian or non-Newtonian)
Non-Newtonian
