Elements, Compounds and Mixtures
Elements, Compounds and Mixtures
Questions
Why is the separation of rock and diamond done by mechanical picking?
- It is because they have different reactivities.
- It is because they have different solubilities.
- It is because they have different colours.
- It is because they have different melting points.
Which of the following can be separated by sublimation?
- Iodine and salt
- Sodium nitrate and sodium chloride
- Sugar and sand
- Iron ore and impurities
Which method is used to seperate a mixture of sand and sulphur?
- Fractional crystallisation
- Solvent extraction
- Sublimation
- Gravity separation
Which property of iron helps in its separation from a mixture?
- High mass of iron
- Magnetic properties
- Chemical properties
- Density of iron
Which method is used to separate sugar and sand?
- Magnetic separation
- Gravity separation
- Mechanical picking
- Solvent extraction
Which characteristic of copper allows it to be easily separated from iron?
- Colour
- Melting point
- Density
- Boiling point
Which method of separation is used when components are soluble in water but their solubilities are different?
- Sublimation
- Fractional crystallization
- Solvent extraction
- Mechanical picking
The process of converting a liquid into its vapour by heating and then condensation of vapour back into liquid is called
- filtration
- evaporation
- distillation
- decanation
By which process are the suspended particles removed from natural water?
- Evaporation
- Solvent extraction
- Filtration
- Sedimentation
Alcohol (boiling point - 78.5°C) and water (boiling point - 100°C) are miscible. How can they be separated?
- Using a separating funnel
- Distillation
- Filtration
- Evaporation
Which of the following methods is used to separate solid-solid mixtures?
- Sedimentation
- Solvent extraction
- Distillation
- Boiling
Which of the following is not common to evaporation and distillation?
- Heating of liquid
- Separation of solid-liquid mixtures
- Separation and recovery of dissolved solid and liquid
- Conversion of liquid to vapour
Which method is used to obtain diesel, natural gases, etc. from crude petroleum?
- Fractional distillation
- Sedimentation
- Filtration
- Solvent extraction
Kerosene and oil are immiscible. How are they commonly separated?
- Distillation
- Evaporation
- Using separating funnel
- Using fractional distillation
Which of the following is not used to separate solid-liquid mixtures?
- Distillation
- Evaporation
- Fractional distillation
- Sedimentation
Which method is used to separate few micrograms of a substance in a mixture?
- Chromatography
- Fractional distillation
- Separating funnel
- Sublimation
Which method utilises difference in boiling points for separation of two miscible liquids?
- Separating funnel
- Chromatography
- Fractional distillation
- Filtration
Which of the following is not true about chromatography?
- It consists of two fixed phases.
- It is used to purify industrial products.
- It identifies different constituents of a mixture.
- It can separate quantities of the order of microgram.
The process of sublimation is used to separate a mixture of salt and ammonium chloride, because
- ammonium chloride directly changes from solid to liquid state on heating
- ammonium chloride directly changes from liquid to solid state on heating
- ammonium chloride directly changes from solid to gaseous state on heating
- ammonium chloride directly changes from gaseous state to solid state on heating
Which of the following is not true regarding methane?
- It is composed of more than one element.
- Its elements are chemically combined.
- Its constituents are separated by chemical or electrochemical means only.
- Its elements are combined in variable proportions.
Which of the following occurs in a free state?
- Krypton
- Germanium
- Hydrogen
- Lead
Which of the following does not have lustre?
- Potassium
- Lead
- Phosphorus
- Copper
Which of the following is not a characteristic of a pure substance?
- It should be essentially homogeneous.
- It should have the same composition.
- It should consist of only elements.
- It should have the same properties.
Which of the following elements is malleable and ductile?
- Potassium
- Sulphur
- Antimony
- Neon
Which of the following is a metalloid?
- Silver
- Mercury
- Bismuth
- Beryllium
Which of the following metals is non-malleable and non-ductile?
- Zinc
- Copper
- Sodium
- Potassium
Which of the following is a poor conductor of electricity?
- Graphite
- Copper wire
- Tungsten wire
- Iron rod
Which of the following exists in monoatomic state?
- Phosphorous
- Chlorine
- Nitrogen
- Neon
Which of the following is a molecule of an element?
- Hydrogen chloride
- Acetic acid
- Ozone
- Water
Which of the following elements is lustrous?
- Fluorine
- Chlorine
- Iodine
- Bromine
Which of the following is not a mixture?
- Acetic acid
- Milk
- Petrol
- Amalgam
Which of the following is a characteristic of compounds?
- Compounds vary in composition and properties.
- Elements in a compound vary in composition.
- Properties of a compound differ from those of its constituent elements.
- Separation of a compound into its elements is not possible chemically.
Which of the following is a homogeneous mixture?
- Petrol in diesel
- Oil in water
- Iron and sulphur
- Sand in water
Which of the following forms a homogenous mixture?
- Alcohol in water
- Oil in water
- Carbon disulphide in water
- Petrol in water
Which of the following is not a property of any individual constituent of sugar?
- Black insoluble solid
- Invisible and odourless
- Crystalline solid
- Gaseous in nature
Which of the following is a heterogeneous mixture?
- Copper + zinc
- Iodine in alcohol
- Sugar in water
- Charcoal and sulphur
Which type of mixture is formed by iodine in alcohol?
- Homogeneous and liquid-liquid mixture
- Homogeneous and solid-liquid mixture
- Heterogeneous and liquid-liquid mixture
- Heterogeneous and solid-liquid mixture
What type of mixture is formed by copper and zinc?
- Heterogeneous and solid-solid mixture
- Homogenous and solid-non solid mixture
- Homogenous and solid-solid mixture
- Heterogeneous and solid-non solid mixture
Which of the following statements is incorrect for an element?
- It cannot be converted into anything simpler.
- Each element consists of only one kind of atom.
- It exists as an individual atom or a molecule.
- Different elements are composed of the same atoms.
- Different elements are composed of the different atoms.
Which of the following is chemically inert?
- Gold
- Carbon
- Beryllium
- Helium
- potassium