WorksheetsGravimetric Method Analysis Exam
Total questions: 49
Worksheet time: 25mins
What is the primary principle of gravimetric analysis?
Volume measurement
Mass measurement
Temperature measurement
pH measurement
Which type of gravimetric analysis involves separating the analyte as a precipitate?
Volatilization gravimetry
Precipitation gravimetry
Electrogravimetry
Gravimetric titrimetry
What is the primary requirement for a precipitate in gravimetric analysis?
High solubility
Purity and stability
High volatility
Reactivity with oxygen
In volatilization gravimetry, the analyte is converted into:
A solid precipitate
A gas of known composition
A liquid solution
An insoluble compound
Which of the following is not a type of gravimetric analysis?
Electrogravimetry
Spectrophotometry
Precipitation gravimetry
Volatilization gravimetry
Which instrument is essential in gravimetric analysis for precise mass determination?
Spectrophotometer
Analytical balance
Conductivity meter
Titration burette
In precipitation gravimetry, what is the final step before weighing the precipitate?
Dissolving the precipitate
Drying or ignition to constant mass
Filtering the precipitate
Adding a secondary reagent
A specific reagent in gravimetric analysis reacts with:
Many chemical species
A single chemical species
Any compound in the solution
Precipitating agents only
Why should precipitates be washed during gravimetric analysis?
To improve crystallization
To remove impurities and adsorbed ions
To increase the solubility of the precipitate
To decrease particle size
What happens if a precipitate is not completely dried before weighing?
The mass will be lower than expected
The analysis remains unaffected
The mass will be higher than expected
The precipitate will dissolve
Which of the following increases the particle size of a precipitate?
High supersaturation
Slow addition of precipitating reagent
Low temperature conditions
No mixing during precipitation
In gravimetric titrimetry, what is measured to determine the analyte concentration?
The mass of a reagent
The volume of a reagent
The intensity of light absorption
The electrical conductivity
Which of the following describes coagulation?
Process of breaking down precipitates
Formation of colloidal particles
Aggregation of fine particles to form larger filterable ones
Complete dissolution of the precipitate
What is the term for a solution containing excess solute beyond saturation?
Saturated solution
Supersaturated solution
Dilute solution
Precipitated solution
What factor affects nucleation rate in precipitation?
Temperature
Pressure
Volume
pH only
The Tyndall effect is associated with:
The scattering of light by colloidal particles
The absorption of heat by a precipitate
The reaction of a precipitate with an acid
The formation of large particles in suspension
What is peptization?
The process of reducing the solubility of a precipitate
The breakdown of a coagulated colloid back into dispersed particles
The formation of a supersaturated solution
The conversion of a gas into a solid
Which of the following is a desirable property of a precipitate in gravimetric analysis?
Large particle size
High solubility
Unstable composition
Susceptibility to oxidation
What does reprecipitation help eliminate?
Adsorbed impurities
Large crystal formations
Excess solvent
Volatile gases
Which factor decreases coprecipitation?
Rapid crystal growth
High supersaturation
Digestion of the precipitate
Excess precipitation reagent
Mixed-crystal formation occurs when:
A foreign ion replaces a lattice ion in a precipitate
Crystals grow without foreign ions
Precipitate dissolves completely
Water is absorbed into the crystal structure
Which factor affects particle growth in precipitation?
Stirring rate
Reactant concentration
Solubility of the precipitate
All of the above
The relative supersaturation equation is used to predict:
Precipitate particle size
Solubility
Evaporation rate
Adsorption capacity
What type of filter paper is used in gravimetric filtration?
Chromatography paper
Quantitative filter paper
Regular tissue paper
Wax paper
The process in which a contaminant is trapped in a crystal pocket is called:
Occlusion
Digestion
Adsorption
Precipitation
Which of the following is not a type of coprecipitation?
Surface adsorption
Mixed-crystal formation
Electrolysis
Mechanical entrapment
What technique is used to slowly generate a precipitating reagent throughout the solution?
Homogeneous precipitation
Electrolysis
Direct precipitation
Volatilization
Which of the following solutions is commonly used to wash silver chloride precipitates?
Pure water
Dilute nitric acid
Sodium hydroxide
Ammonium sulfate
The mass versus temperature graph in thermal decomposition is called a:
Tyndall curve
Thermogram
Digestion curve
Adsorption chart
What is the weighing form in gravimetric analysis?
The precipitate after washing
The final compound weighed after ignition
The raw sample solution
The reagent used for precipitation
Which of the following factors can increase crystal growth in precipitation?
Rapid addition of precipitating reagent
High supersaturation
Slow precipitation and digestion
High agitation
What is the role of desiccants in volatilization gravimetry?
To absorb excess reactants
To collect water or other volatile compounds
To increase reaction rates
To decrease the solubility of precipitates
Digestion of a precipitate helps to:
Improve crystal purity and filterability
Reduce the solubility of the precipitate
Increase the number of small particles
Break down large particles into smaller ones
Which of the following can reduce errors in gravimetric analysis?
Using an uncalibrated balance
Washing precipitate with pure water only
Ensuring complete drying or ignition
Filtering quickly without washing
The electrogravimetric method involves:
Precipitation by chemical reaction
Heating a sample to release a volatile product
Deposition of the analyte onto an electrode
Measuring solubility of a precipitate
Coagulation of colloids can be improved by:
Rapid stirring
Adding an electrolyte
Heating at high temperatures
Precipitating from a supersaturated solution
Which of the following affects the rate of nucleation in precipitation?
Ionic strength of the solution
Presence of dust particles
Temperature of the solution
All of the above
What is the purpose of ignition in gravimetric analysis?
To remove volatile impurities and ensure constant mass
To dissolve the precipitate
To reduce solubility
To improve filtration
The Tyndall effect in colloidal systems is caused by:
Scattering of light by small particles
Complete dissolution of the precipitate
Precipitation of large crystals
Decrease in solubility
Why is gravimetric analysis considered highly accurate?
It relies on precise mass measurements
It requires expensive instruments
It uses highly volatile reagents
It does not require any filtration
What is the main disadvantage of gravimetric methods?
It requires expensive chemicals
It is time-consuming
It is less accurate than volumetric methods
It does not work for inorganic compounds
Which compound is commonly used as a precipitating agent for sulfate ions?
Silver nitrate
Barium chloride
Sodium chloride
Calcium hydroxide
Occlusion in gravimetric analysis refers to:
The entrapment of impurities within growing crystals
The adsorption of contaminants on the precipitate surface
The loss of precipitate during filtration
The formation of a supersaturated solution
Which of the following is an ideal property of a precipitating reagent?
Reacts selectively with many compounds
Forms a highly soluble precipitate
Produces a stable, easily filterable precipitate
Reacts with atmospheric gases
The process of separating analytes by converting them into a gas is called:
Precipitation gravimetry
Electrogravimetry
Volatilization gravimetry
Gravimetric titrimetry
A solution where a precipitate forms evenly without local excesses of reagents is called:
Crystalline precipitation
Homogeneous precipitation
Mixed-crystal formation
Adsorption precipitation
In gravimetric analysis, what is the main cause of errors?
Contamination of the precipitate
Use of excess reagents
Slow filtration rate
Lack of heating
What happens when a coagulated precipitate is washed with pure water?
The precipitate dissolves completely
Peptization occurs, dispersing the particles
The precipitate grows larger
Adsorption is increased
Thermogravimetric analysis (TGA) is used to:
Measure mass changes with temperature
Identify the size of precipitate particles
Test the solubility of precipitates
Determine the color of the precipitate
