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Answer: A
Q36
Bulkiness equals reciprocal of:
A) True density
B) Bulk density
C) Granule density
D) Particle density
Answer: B
Q37
Bulkiness increases when particle size:
A) Increases
B) Decreases
C) ثابت
D) disappears
Answer: B
Q38
Flow properties affected by:
A) Particle size
B) Particle shape
C) Surface texture
D) All of the above
Answer: D
Q39
Particles smaller than 10 µm show:
A) Excellent flow
B) Poor flow
C) No flow
D) Perfect packing
Answer: B
Q40
Poor powder flow due to moisture can be improved by:
A) Heating
B) Drying
C) Cooling
D) Filtering
Answer: B
Q1
Micromeritics is the science concerned with:
A) Liquids
B) Small particles
C) Gases
D) Solutions
Answer: B
Q2
1 micrometer equals:
A) 10⁻³ m
B) 10⁻⁶ m
C) 10⁻⁹ m
D) 10⁻² m
Answer: B
Q3
Polydisperse system means particles:
A) Same shape
B) Same density
C) Different sizes
D) Same surface area
Answer: C
Q4
Equivalent spherical diameter is used when particles are:
A) Spherical
B) Regular
C) Irregular
D) Uniform
Answer: C
Q5
Surface diameter (ds) is used in:
A) Dissolution
B) Adsorption
C) Both A and B
D) Density
Answer: C
Q6
Volume diameter (dv) relates to:
A) Density
B) Mass
C) Volume
D) All of the above
Answer: D
Q7
Stokes diameter depends on:
A) Surface area
B) Sedimentation rate
C) Shape only
D) Weight only
Answer: B
Q8
Particle size distribution curve plots particle size versus:
A) Porosity
B) Density
C) Frequency
D) Volume
Answer: C
Q9
Frequency distribution curve Y-axis represents:
A) Particle size
B) Particle diameter
C) Frequency
D) Volume
Answer: C
Q10
Optical microscope measures particles within range:
A) 0.2–100 µm
B) 1–1000 µm
C) 44–500 µm
D) 10–200 µm
Answer: A
Q11
Recommended particle number counted microscopically:
A) 50–100
B) 100–200
C) 300–500
D) 500–1000
Answer: C
Q12
Microscopy disadvantage:
A) Expensive
B) Measures only two dimensions
C) Measures depth accurately
D) Fast method
Answer: B
Q13
Sieving method suitable mainly for:
A) Fine particles
B) Coarse particles
C) Nanoparticles
D) Liquids
Answer: B
Q14
Smallest particle size measurable by sieving:
A) 10 µm
B) 25 µm
C) 44 µm
D) 100 µm
Answer: C
Q15
Sieving errors caused by:
A) Sample weight
B) Shaking time
C) Agitation intensity
D) All of the above
Answer: D
Q16
Sedimentation method applies to particles smaller than:
A) 100 µm
B) 44 µm
C) 10 µm
D) 1 µm
Answer: B
Q17
Sedimentation method is based on:
A) Boyle’s law
B) Stokes’ law
C) Newton’s law
D) Raoult’s law
Answer: B
Q18
Stokes law assumes particles:
A) Aggregated
B) Cubical
C) Spherical
D) Rectangular
Answer: C
Q19
Stokes law valid when particles move with:
A) Variable velocity
B) Constant velocity
C) Zero velocity
D) High velocity
Answer: B
Q20
Particle aggregation during sedimentation causes:
A) Accurate results
B) Faster settling
C) Slower settling
D) No change
Answer: B
Q21
Particle shape affects:
A) Flow
B) Packing
C) Surface area
D) All of the above
Answer: D
Q22
Spherical particles have:
A) Maximum surface area
B) Minimum surface area
C) No surface area
D) Infinite surface area
Answer: B
Q23
Irregular particles show:
A) Better flow
B) Loose packing
C) Larger surface area
D) Both B and C
Answer: D
Q24
Increase surface area increases:
A) Density
B) Solubility
C) Weight
D) Volume
Answer: B
Q25
Specific surface equals surface area per unit:
A) Weight
B) Volume
C) Both
D) Length
Answer: C
Q26
BET method determines:
A) Porosity
B) Density
C) Surface area
D) Diameter
Answer: C
Q27
Air permeability method depends on:
A) Pressure only
B) Surface area
C) Temperature only
D) Volume
Answer: B
Q28
Increase surface area leads to:
A) Increased airflow
B) Increased resistance
C) No change
D) Decreased adsorption
Answer: B
Q29
Porosity equals:
A) Bulk volume / void volume
B) Void volume / bulk volume
C) True volume / bulk volume
D) Weight / volume
Answer: B
Q30
Closest packing porosity:
A) 26%
B) 48%
C) 30%
D) 50%
Answer: A
Q31
Loosest packing porosity:
A) 26%
B) 48%
C) 30%
D) 60%
Answer: B
Q32
Most powders porosity ranges between:
A) 10–20%
B) 30–50%
C) 50–70%
D) 70–90%
Answer: B
Q33
True density excludes:
A) Interparticle spaces
B) Intraparticle pores
C) Crystal lattice voids
D) All of the above
Answer: D
Q34
Granule density measured using:
A) Water
B) Mercury
C) Alcohol
D) Oil
Answer: B
Q35
Bulk density calculated from:
A) Weight and bulk volume
B) Weight and true volume
C) Density and volume
D) Surface area
Q1 – Porosity
A powder sample has:
Bulk volume = 80 cm³
True volume = 60 cm³
Porosity equals:
A) 10%
B) 20%
C) 25%
D) 40%
الحل الوزاري المختصر:
Void volume = 80 − 60 = 20
Porosity = 20 / 80 = 0.25 = 25%
Answer: C
Q2 – Porosity
Bulk volume = 100 cm³
Void volume = 30 cm³
Porosity equals:
A) 0.3
B) 0.7
C) 3
D) 30
Answer: A
(لأن Porosity = void / bulk)
Q3 – True volume
Weight = 120 g
True density = 3 g/cm³
True volume equals:
A) 20
B) 30
C) 40
D) 60
الحل:
Volume = weight / density
= 120 / 3 = 40
Answer: C
Q4 – Bulk density
Weight = 100 g
Bulk volume = 50 cm³
Bulk density equals:
A) 0.5
B) 2
C) 5
D) 10
الحل:
Bulk density = weight / bulk volume
= 100 / 50 = 2
Answer: B
Q5 – Bulkiness
Bulk density = 0.5 g/cm³
Bulkiness equals:
A) 0.5
B) 1
C) 2
D) 5
الحل:
Bulkiness = 1 / bulk density
= 1 / 0.5 = 2
Answer: C
Q6 – Void volume
Bulk volume = 90 cm³
True volume = 70 cm³
Void volume equals:
A) 10
B) 20
C) 30
D) 40
الحل:
Void = bulk − true
= 90 − 70 = 20
Answer: B
Q7 – Porosity percent
Void volume = 25
Bulk volume = 100
Porosity (%) equals:
A) 15%
B) 20%
C) 25%
D) 30%
Answer: C
Q8 – True volume from density
Weight = 200 g
True density = 4 g/cm³
True volume equals:
A) 25
B) 50
C) 75
D) 100
الحل:
Volume = weight / density
= 200 / 4 = 50
Answer: B
Q9 – Packing arrangement
Porosity theoretical value in closest packing equals:
A) 26%
B) 30%
C) 48%
D) 50%
Answer: A
Q10 – Packing arrangement
Porosity theoretical value in loosest packing equals:
A) 26%
B) 48%
C) 30%
D) 50%
Answer: B
Q11 – Bulk density calculation
Weight = 150 g
Bulk volume = 75 cm³
Bulk density equals:
A) 1
B) 2
C) 3
D) 4
الحل:
150 / 75 = 2
Answer: B
Q12 – Porosity calculation (نمط وزاري مشهور جدًا)
Weight = 131.3 g
True density = 3.203 g/cm³
Bulk volume = 82 cm³
True volume equals:
A) 20
B) 30
C) 41
D) 60
الحل:
True volume = weight / density
≈ 131.3 / 3.203
≈ 41
Answer: C
(هذا المثال نفسه موجود بالمحاضرة وغالبًا يجي امتحان)
أهم القوانين الوزارية اللي تحفظها قبل الامتحان ⭐
1️⃣ Porosity
ε = Void volume / Bulk volume
2️⃣ Void volume
Void = Bulk − True
3️⃣ True volume
True volume = Weight / True density
4️⃣ Bulk density
Bulk density = Weight / Bulk volume
5️⃣ Bulkiness
Bulkiness = 1 / Bulk density
MCQ وزاري – Micromeritics
Q1
The science that deals with small particles is called:
A) Rheology
B) Micromeritics
C) Diffusion
D) Sedimentation
Answer: B
Q2
The unit most commonly used in micromeritics is:
A) nm
B) cm
C) µm
D) mm
Answer: C
Q3
Surface diameter (ds) is based on:
A) Volume
B) Sedimentation rate
C) Surface area
D) Density
Answer: C
Q4
Volume diameter (dv) is used in determination of:
A) Density and mass
B) Flow rate
C) Adsorption
D) Dissolution
Answer: A
Q5
Stokes diameter (dst) depends on:
A) Surface area
B) Sedimentation velocity
C) Particle color
D) Shape only
Answer: B
Q6
Equivalent spherical diameter is used because:
A) Particles are always spherical
B) Particles are always cubic
C) Irregular particles have no single true diameter
D) Particles dissolve rapidly
Answer: C
Q7
Particle size distribution curve plots particle size versus:
A) Density
B) Frequency
C) Shape
D) Viscosity
Answer: B
Q8
In particle size distribution curve:
X-axis represents:
A) Frequency
B) Density
C) Particle size
D) Porosity
Answer: C
Q9
Optical microscopy measures particle size range:
A) 0.001 – 1 µm
B) 0.2 – 100 µm
C) 100 – 500 µm
D) 1 – 1000 µm
Answer: B
Q10
Recommended number of particles counted in microscopy method:
A) 10–50
B) 50–100
C) 300–500
D) 1000
Answer: C
Q11
Main disadvantage of microscopic method:
A) Expensive
B) Measures only two dimensions
C) Cannot measure size
D) Requires heating
Answer: B
Q12
Sieving method is suitable mainly for:
A) Fine particles
B) Coarse particles
C) Nanoparticles
D) Liquids
Answer: B
Q13
Minimum particle size measurable by sieving:
A) 10 µm
B) 25 µm
C) 44 µm
D) 100 µm
Answer: C
Q14
Sedimentation method is based on:
A) Newton’s law
B) Stokes’ law
C) Boyle’s law
D) Fick’s law
Answer: B
Q15
Stokes’ law applies exactly when particles are:
A) Cubic
B) Aggregated
C) Spherical
D) Colored
Answer: C
Q16
Stokes’ equation is valid when particles:
A) Are aggregated
B) Move with constant velocity
C) Are irregular
D) Are heated
Answer: B
Q17
Particle shape affects:
A) Flow properties
B) Packing properties
C) Surface area
D) All of the above
Answer: D
Q18
Spherical particles have:
A) Maximum surface area
B) Minimum surface area
C) No surface area
D) Variable surface area
Answer: B
Q19
Increase in surface area leads to increase in:
A) Density
B) Solubility
C) Viscosity
D) Weight
Answer: B
Q20
BET method measures:
A) Density
B) Surface area
C) Particle size
D) Porosity
Answer: B
Q21
Air permeability method depends on:
A) Surface area
B) Color
C) Density
D) Weight
Answer: A
Q22
Porosity is defined as ratio of:
A) True volume / bulk volume
B) Void volume / bulk volume
C) Bulk volume / void volume
D) Weight / volume
Answer: B
Q23
Porosity of closest packing equals:
A) 26%
B) 48%
C) 30%
D) 50%
Answer: A
Q24
Porosity of loosest packing equals:
A) 26%
B) 48%
C) 30%
D) 60%
Answer: B
Q25
Bulk density depends mainly on:
A) Particle size
B) Particle shape
C) Particle adhesion
D) All of the above
Answer: D
Q26
Bulkiness is the reciprocal of:
A) True density
B) Granule density
C) Bulk density
D) Porosity
Answer: C
Q27
Particles smaller than 10 µm show poor flow due to:
A) Gravity increase
B) Cohesive forces
C) Density decrease
D) Surface tension
Answer: B
Q28
Flow rate becomes maximum at:
A) Small particle size
B) Medium particle size
C) Very large particle size
D) Nanoparticles
Answer: B
هذا التقرير مال ماده فيزياء اذا احد يريد يكتب فهذا جاهز بدون ماتدور وتتعب
Research: Dissolving 1 Milliliter of Paracetamol in 10 Grams of Ethanol
1. Introduction
Paracetamol (also known as acetaminophen) is one of the most widely used medications in the world. It is commonly used as an analgesic (pain reliever) and antipyretic (fever reducer). This compound has physical and chemical properties that allow it to dissolve in several organic solvents such as ethanol, while its solubility in water is relatively lower.
Ethanol is a polar organic solvent widely used in chemistry and pharmaceutical sciences due to its ability to dissolve many organic compounds.
Scientific studies indicate that the solubility of paracetamol in ethanol is approximately 18 grams per 100 mL at room temperature, which is significantly higher than its solubility in water.
This experiment aims to study the dissolution process between paracetamol and ethanol and observe the formation of a homogeneous solution.
2. Aim of the Experiment
The objectives of this experiment are:
To study the solubility of paracetamol in ethanol.
To observe the physical changes during the dissolution process.
To understand the interaction between an organic solvent and a pharmaceutical compound.
To prepare a homogeneous solution of paracetamol.
3. Materials and Apparatus
Chemicals
Paracetamol
Ethanol
Apparatus
Electronic balance
Graduated cylinder
Beaker
Glass stirring rod
Pipette
Thermometer (optional)
4. Theory
Dissolution
Dissolution is the process in which a solid substance (solute) mixes with a liquid substance (solvent) to form a homogeneous solution.
The dissolution process depends on several factors:
Nature of the solute and solvent
Temperature
Stirring
Surface area of the solute
Ethanol is a partially polar solvent capable of dissolving organic compounds like paracetamol due to hydrogen bonding interactions between molecules.
Solubility
The solubility of paracetamol in ethanol is relatively high and can reach approximately 18 g per 100 mL of ethanol at room temperature.
Therefore, a small amount of paracetamol can dissolve easily in ethanol.
5. Experimental Procedure
Measure approximately 1 milliliter of paracetamol (or the equivalent mass) using an electronic balance.
Measure 10 grams of ethanol using a graduated cylinder.
Pour the ethanol into a clean beaker.
Gradually add the paracetamol to the ethanol.
Stir the mixture using a glass rod.
Observe the dissolution process until a clear solution forms.
Record observations such as:
Rate of dissolution
Color of the solution
Presence or absence of residue.
6. Expected Results
After adding paracetamol to ethanol and stirring:
The paracetamol gradually dissolves in the ethanol.
A clear or slightly transparent solution forms.
No solid residue should appear if the amount added is within the solubility limit.
7. Discussion
The dissolution rate in this experiment depends on several factors:
1. Nature of the Solvent
Ethanol is partially polar, which allows it to form hydrogen bonds with paracetamol molecules.
2. Stirring
Stirring increases the rate of dissolution by improving contact between the solute and the solvent.
3. Temperature
Higher temperature increases molecular motion, which accelerates the dissolution process.
4. Solution Concentration
If the amount of paracetamol exceeds its solubility limit, some of the solid will remain undissolved and settle at the bottom of the container.
8. Safety Precautions
Ethanol should be handled away from open flames because it is highly flammable.
Wear gloves and safety goggles during the experiment.
Work in a well-ventilated area.
Avoid contact of chemicals with skin or eyes.
9. Conclusion
The experiment demonstrates that paracetamol dissolves readily in ethanol due to interactions between the polar molecules of the solvent and the solute.
The results confirm that ethanol is an effective solvent for preparing paracetamol solutions, which explains its use in certain pharmaceutical and chemical applications.
In addition, factors such as stirring, temperature, and concentration significantly influence the efficiency and speed of the dissolution process
