During preparation of amorphous silicon, the product is washed with hydrofluoric acid to

During preparation of amorphous silicon, the product is washed with hydrofluoric acid to
by

1 Answer

Answer :

remove unreacted silica.
by

Related questions

During preparation of amorphous silicon, product is washed with

Description : During preparation of amorphous silicon, product is washed with

Last Answer : dilute hydrochloric acid to dissolve magnesium oxide.

What is the role of the following in the extraction of amorphous silicon? a) Hydrochloric acid b) hydrofluoric acid

Description : What is the role of the following in the extraction of amorphous silicon? a) Hydrochloric acid b) hydrofluoric acid

Last Answer : a) Hydrochloric acid is used to dissolve magnesium oxide b) Hydrofluoric acid is used to remove unreacted silica

Hydrofluoric acid is not kept in glass bottles because it reacts with - (1) visible light (2) silicon dioxide of glass (3) aluminium oxide of glass (4) sodium oxide of glass

Description : Hydrofluoric acid is not kept in glass bottles because it reacts with - (1) visible light (2) silicon dioxide of glass (3) aluminium oxide of glass (4) sodium oxide of glass

Last Answer : (2) silicon dioxide of glass

Amorphous silicon is obtained by heating silica with

Description : Amorphous silicon is obtained by heating silica with

Last Answer : magnesium powder.

What happens when amorphous silicon is heated?

Description : What happens when amorphous silicon is heated?

Last Answer : When amorphous silicon is heated in air, it oxidizes at the surface level & catches fire.

Compare the properties of amorphous and crystalline silicon

Description : Compare the properties of amorphous and crystalline silicon

Last Answer : morphous silicon It is a brown powder It does not conduct electricity at low temperatures. It is more reactive than crystalline silicon When heated in air, it oxidizes at the surface level ... electricity It is less reactive than amorphous silicon It does not burn in air even when heated

Briefly explain the extraction of amorphous silicon.

Description : Briefly explain the extraction of amorphous silicon.

Last Answer : Finely powdered silica (sand or quartz) is mixed with magnesium powder and heated in a fire clay crucible. Magnesium oxide and silicon are formed

State the application of following materials : i) CRGO Silicon Steel ii) HRGO Silicon Steel iii) Amorphous metal iv) Bronze

Description : State the application of following materials : i) CRGO Silicon Steel ii) HRGO Silicon Steel iii) Amorphous metal iv) Bronze 

Last Answer : Applications of CRGO Silicon Steel: 1) Manufacturing distribution and power transformer cores. 2) Manufacturing cores of audio transformers, ballast transformers, specialty transformers. 3) Manufacturing cores ... used. 5) Cadmium bronze is used for making commutator segments and contact wires. 

Surface preparation for Metallising the abrasives used for final cleaning is a) Chilled iron grit G.24, as defined in BS : 2451 b) Washed salt free angular silica sand of mesh size 12 to 30 with a minimum of 40% retained on a 20 mesh c) either (a) or (b) * d) d) neither (a) or (b)

Description : Surface preparation for Metallising the abrasives used for final cleaning is a) Chilled iron grit G.24, as defined in BS : 2451 b) Washed salt free angular silica sand of mesh size 12 to 30 with a minimum of 40% retained on a 20 mesh c) either (a) or (b) * d) d) neither (a) or (b)

Last Answer : c) either (a) or (b) *

Is hydrofluoric acid attacking glass and etching designs in glass a physical change?

Description : Is hydrofluoric acid attacking glass and etching designs in glass a physical change?

Last Answer : No, it is a chemical change. The glass is changed into newsubstances where it is etched.

Is hydrofluoric acid ionic or covalent bonding?

Description : Is hydrofluoric acid ionic or covalent bonding?

Last Answer : What is the answer ?

Which one of the following acids is used in battery? (1) Hydrochloric acid (2) Hydrofluoric acid (3) Sulphuric acid (4) Sulphurous acid

Description : Which one of the following acids is used in battery? (1) Hydrochloric acid (2) Hydrofluoric acid (3) Sulphuric acid (4) Sulphurous acid

Last Answer : (3) Sulphuric acid Explanation: Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Possessing different chemical properties ... domestic acidic drain cleaner, electrolyte in lead-acid batteries and various cleaning agents.

Addition polymerisation takes place either by a free radical mechanism or ionic mechanism depending on the reagents used. Free radical polymerisation is catalyzed by __________, which decompose to give free radicals. (A) Organic peroxides (B) Sulphuric acid (C) Hydrofluoric acid (D) None of these

Description : Addition polymerisation takes place either by a free radical mechanism or ionic mechanism depending on the reagents used. Free radical polymerisation is catalyzed by __________, which decompose to give free radicals. (A) Organic peroxides (B) Sulphuric acid (C) Hydrofluoric acid (D) None of these

Last Answer : (A) Organic peroxides

Which of the following would not be a suitable material of construction for handling aqueous hydrofluoric acid (HF) at 100°C? (A) Monel (B) Stainless steel (C) Graphite (D) Kel-F and Teflon

Description : Which of the following would not be a suitable material of construction for handling aqueous hydrofluoric acid (HF) at 100°C? (A) Monel (B) Stainless steel (C) Graphite (D) Kel-F and Teflon

Last Answer : (B) Stainless steel

Glass lined vessels are not used for handling (A) Dilute H2SO4 (B) Dilute HNO3 (C) Dilute HCI (D) Hydrofluoric acid

Description : Glass lined vessels are not used for handling (A) Dilute H2SO4 (B) Dilute HNO3 (C) Dilute HCI (D) Hydrofluoric acid

Last Answer : (D) Hydrofluoric acid

Glass lined vessels are not used for handling/storing (A) Dilute H2SO4 (B) Dilute HNO3 (C) Dilute HCl (D) Hydrofluoric acid

Description : Glass lined vessels are not used for handling/storing (A) Dilute H2SO4 (B) Dilute HNO3 (C) Dilute HCl (D) Hydrofluoric acid

Last Answer : (D) Hydrofluoric acid

Nitro-glycerine absorbed in wood flour, sodium nitrate or ammonium nitrate is commercially used as controlled explosive called dynamite. The raw material used for its manufacture are glycerine, nitric acid and (A) Sulphuric acid (B) Phosphoric acid (C) Hydrochloric acid (D) Hydrofluoric acid

Description : Nitro-glycerine absorbed in wood flour, sodium nitrate or ammonium nitrate is commercially used as controlled explosive called dynamite. The raw material used for its manufacture are glycerine, nitric acid and (A) Sulphuric acid (B) Phosphoric acid (C) Hydrochloric acid (D) Hydrofluoric acid

Last Answer : (A) Sulphuric acid

Laboratory glass wares which reacts with hydrofluoric acid, are made of the __________ glass. (A) Lead (B) Borosilicate (C) Soda lime (D) Alkali silicate

Description : Laboratory glass wares which reacts with hydrofluoric acid, are made of the __________ glass. (A) Lead (B) Borosilicate (C) Soda lime (D) Alkali silicate

Last Answer : (B) Borosilicate

Which of the following is the weakest acid? w) hydrochloric acid x) hydrofluoric acid y) sulfuric acid z) nitric acid

Description : Which of the following is the weakest acid? w) hydrochloric acid x) hydrofluoric acid y) sulfuric acid z) nitric acid

Last Answer : ANSWER: X -- HYDROFLUORIC ACID

Which one of the following acids is used in battery ? (1) Hydrochloric acid (2) Hydrofluoric acid (3) Sulphuric acid (4) Sulphurous acid

Description : Which one of the following acids is used in battery ? (1) Hydrochloric acid (2) Hydrofluoric acid (3) Sulphuric acid (4) Sulphurous acid

Last Answer : Sulphuric acid

The compound of silicon used in preparation of glass is

Description : The compound of silicon used in preparation of glass is

Last Answer : sand.

Describe the preparation of a silicon substrate

Description : Describe the preparation of a silicon substrate

Last Answer : Crystal is sliced into wafers. Then ground and polished to remove any surface defect.

What are the various Silicon wafer Preparation? _

Description : What are the various Silicon wafer Preparation? _

Last Answer : Crystal growth & doping _ Ingot trimming & grinding _ Ingot slicing _ Wafer polishing & etching _ Wafer cleaning.

If a material has the capacity to behave either as an acid or a base it is said to be: w) amorphous x) amphoteric y) anhydrous z) aklaline

Description : If a material has the capacity to behave either as an acid or a base it is said to be: w) amorphous x) amphoteric y) anhydrous z) aklaline

Last Answer : ANSWER: X -- AMPHOTERIC

In coal washeries, three products namely the valuable product (i.e. clean/washed coal), discarded product (i.e. mineral matter) and an additional concentrated product called __________ is produced. (A) Concentrate (B) Tailing (C) Middling (D) None of these

Description : In coal washeries, three products namely the valuable product (i.e. clean/washed coal), discarded product (i.e. mineral matter) and an additional concentrated product called __________ is produced. (A) Concentrate (B) Tailing (C) Middling (D) None of these

Last Answer : (C) Middling

Are acid washed jeans back in style now?

Description : Are acid washed jeans back in style now?

Last Answer : Acid-washed jeans were in style a couple of years ago, but aren't so hot at the moment, although they're still available in stores. No, acid wash jeans are an 80's fashion though some people still wear them.

Transparent soaps (e.g. Pears) are (A) Usually soft soap (made from coconut oil) in which cane sugar & alcohol are added and finally washed with methylated spirit to achieve transparency (B) Metallic soaps with frothing agent and free Stearic acid to achieve transparency (C) Metallic soaps with frothing agent from which glycerine has not been recovered (D) None of these

Description : Transparent soaps (e.g. Pears) are (A) Usually soft soap (made from coconut oil) in which cane sugar & alcohol are added and finally washed with methylated spirit to achieve transparency (B) ... (C) Metallic soaps with frothing agent from which glycerine has not been recovered (D) None of these

Last Answer : (A) Usually soft soap (made from coconut oil) in which cane sugar & alcohol are added and finally washed with methylated spirit to achieve transparency

What happens if the solution in the conical flask gets washed with distilled water during the experiment?

Description : What happens if the solution in the conical flask gets washed with distilled water during the experiment?

Last Answer : That will depend on what the solution is, as well as many otherpossible conditions what you failed to specify in yourquestion.

Charcoal is (a) Amorphous (b) Crystalline (c) Hygroscopic (d) None of these

Description : Charcoal is (a) Amorphous (b) Crystalline (c) Hygroscopic (d) None of these

Last Answer : Ans:(a)

Diamond is the form of carbon that is (a) Crystalline (b) Amorphous (c) Chemical (d) Alkaline

Description : Diamond is the form of carbon that is (a) Crystalline (b) Amorphous (c) Chemical (d) Alkaline

Last Answer : Ans:(a)

A ligament is (a) A fibrous tissue that joins the muscle to bone (b) A type of amorphous gel that cements non movable joints together (c) A type of fibrous connective tissue that joins bones together at joints (d) Only formed to repair damaged muscle tissue

Description : A ligament is (a) A fibrous tissue that joins the muscle to bone (b) A type of amorphous gel that cements non movable joints together (c) A type of fibrous connective tissue that joins bones together at joints (d) Only formed to repair damaged muscle tissue

Last Answer : Ans:(c)

On heating, a white amorphous inorganic compound becomes yellow and on cooling, turns white again. The salt may be

Description : On heating, a white amorphous inorganic compound becomes yellow and on cooling, turns white again. The salt may be

Last Answer : On heating, a white amorphous inorganic compound becomes yellow and on cooling, turns white again. The salt may be A. ... `ZnCO_(3)` D. `K_(2)CO_(3)`

Find incorrect statement with regard to centrosome and centrioles :- (a) Centrosomes are surrounded by amorphous pericentriolar material (b) In centro

Description : Find incorrect statement with regard to centrosome and centrioles :- (a) Centrosomes are surrounded by amorphous pericentriolar material (b) In centro

Last Answer : Find incorrect statement with regard to centrosome and centrioles :- (a) Centrosomes are surrounded by amorphous ... b C. b, c D. All are correct

Diamond is the form of carbon that is - (1) Crystalline (2) Amorphous (3) Chemical (4) Alkaline

Description : Diamond is the form of carbon that is - (1) Crystalline (2) Amorphous (3) Chemical (4) Alkaline

Last Answer : (1) Crystalline Explanation: Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic.

Most of the fibre forming polymers are crystalline in nature, one of the exceptions being __________ which is amorphous in nature. (A) Nylon (B) Polyacrylonitrile (C) Polypropylene (D) Polyester

Description : Most of the fibre forming polymers are crystalline in nature, one of the exceptions being __________ which is amorphous in nature. (A) Nylon (B) Polyacrylonitrile (C) Polypropylene (D) Polyester

Last Answer : (B) Polyacrylonitrile

. The physical state in which polymers exist is (A) Melts & rubber like state (B) Amorphous glassy state (C) Partially crystalline state (D) All (A), (B) and (C)

Description : . The physical state in which polymers exist is (A) Melts & rubber like state (B) Amorphous glassy state (C) Partially crystalline state (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Orlan fibre which is used as a wool substitute is (A) An amorphous polymer (B) A natural polymeric fibre (C) Polyacrylonitrile (D) Poly-methyl-methacrylate (PMMA)

Description : Orlan fibre which is used as a wool substitute is (A) An amorphous polymer (B) A natural polymeric fibre (C) Polyacrylonitrile (D) Poly-methyl-methacrylate (PMMA)

Last Answer : (C) Polyacrylonitrile

Ceramic materials are (A) Organic in nature (B) Stronger in compression than in tension (C) Always amorphous in nature (D) Always bad heat conductors

Description : Ceramic materials are (A) Organic in nature (B) Stronger in compression than in tension (C) Always amorphous in nature (D) Always bad heat conductors

Last Answer : (B) Stronger in compression than in tension

Which is an amorphous material? (A) Glass (B) Mica (C) Brass (D) Cast iron

Description : Which is an amorphous material? (A) Glass (B) Mica (C) Brass (D) Cast iron

Last Answer : (A) Glass

Common house hold glass (i.e., soda-lime glass) is a/an __________ material. (A) Fully crystalline (B) Partly crystalline (C) Amorphous

Description : Common house hold glass (i.e., soda-lime glass) is a/an __________ material. (A) Fully crystalline (B) Partly crystalline (C) Amorphous

Last Answer : (B) Partly crystalline

How can a material be made amorphous ?

Description : How can a material be made amorphous ? 

Last Answer : By melting the material and by cooling it rapidly.

With increase in temperature, the thermal conductivity of non-metallic amorphous solids (A) Decreases (B) Increases (C) Remain constant (D) First decreases upto certain temperature and then increases

Description : With increase in temperature, the thermal conductivity of non-metallic amorphous solids (A) Decreases (B) Increases (C) Remain constant (D) First decreases upto certain temperature and then increases

Last Answer : (B) Increases

Ordinary glass is not a/an (A) Amorphous isotropic material (B) Supercooled liquid (C) Material with sharp definite melting point (D) Electrical insulator

Description : Ordinary glass is not a/an (A) Amorphous isotropic material (B) Supercooled liquid (C) Material with sharp definite melting point (D) Electrical insulator

Last Answer : (C) Material with sharp definite melting point

While the thermosetting polymers are amorphous in nature, the thermoplastic polymers are either amorphous or crystalline. The crystalline polymers are characterised by the (A) Low impact strength (B) High flexibility (C) Better finish and surface appearance (D) High plastic deformation

Description : While the thermosetting polymers are amorphous in nature, the thermoplastic polymers are either amorphous or crystalline. The crystalline polymers are characterised by the (A) Low impact strength (B) High flexibility (C) Better finish and surface appearance (D) High plastic deformation

Last Answer : A) Low impact strength

Viscoelastic behaviour is observed in __________ materials. (A) Non-crystalline organic polymeric (B) Ceramic (C) All crystalline (D) All amorphous

Description : Viscoelastic behaviour is observed in __________ materials. (A) Non-crystalline organic polymeric (B) Ceramic (C) All crystalline (D) All amorphous

Last Answer : Non-crystalline organic polymeric

Wood is a/an __________ material. (A) Amorphous (B) Cellular (C) Homogeneous (D) Granular

Description : Wood is a/an __________ material. (A) Amorphous (B) Cellular (C) Homogeneous (D) Granular

Last Answer : (B) Cellular

In an amorphous material, atoms defy any definite atomic structure and exist in random pattern just like in liquid. Which of the following is an amorphous material? (A) Tin(B) Lead (C) Zinc (D) Glass

Description : In an amorphous material, atoms defy any definite atomic structure and exist in random pattern just like in liquid. Which of the following is an amorphous material? (A) Tin (B) Lead (C) Zinc (D) Glass

Last Answer : Option D

Quick lime (or caustic lime) (A) Is obtained by the calcination of pure lime stone (B) Has great affinity to moisture (C) Is amorphous (D) All the abov

Description : Quick lime (or caustic lime) (A) Is obtained by the calcination of pure lime stone (B) Has great affinity to moisture (C) Is amorphous (D) All the above

Last Answer : Answer: Option D

In calculus formation, the epitaxic concept is one of the theories. Which of the following is true: a. Mineralisation occurs when calcium and phosphate content is high. b. The presence of matrix would start initial formation of nucleus. c. The amorphous materials would convert to calcium phosphate and hydroxy phosphate.

Description : In calculus formation, the epitaxic concept is one of the theories. Which of the following is true: a. Mineralisation occurs when calcium and phosphate content is high. b. The presence of ... of nucleus. c. The amorphous materials would convert to calcium phosphate and hydroxy phosphate.

Last Answer : b. The presence of matrix would start initial formation of nucleus.

In calculus formation the epitaxic concept is one of the theories. Which of the following is true: A. Mineralisation occurs when calcium and phosphate content is high B. The presence of matrix would initiate the formation of the nucleus C. The amorphous materials would convert to calcium phosphate and hydroxy

Description : In calculus formation the epitaxic concept is one of the theories. Which of the following is true: A. Mineralisation occurs when calcium and phosphate content is high B. The presence of ... the formation of the nucleus C. The amorphous materials would convert to calcium phosphate and hydroxy

Last Answer : B. The presence of matrix would initiate the formation of the nucleus