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Laboratory PREPARATION: It is usually obtained by boiling white phosphorus with 30-40% solution of caustic soda in an inert atmosphere of CO2.

P4 + 3NaOH + 3H2O → PH3 + 3NaH2PO2 (Sodium hypophosphite)

Phosphine so obtained is impure. It is passed into an aqueous solution of hydrogen iodide, PH4I is formed. PH4I is HEATED with KOH or NaOH, pure phosphine is obtained.

PH3 + HI → PH4I

PH4I + NaOH → PH3 + NaI + H2O

Physical properties

Phosphine is colourless gas with rotten fish odour.

Chemical properties

Dissociation: Phosphine dissociates at about 723 K and gives red phosphorus.

4PH3 P4 →(23K)→ 6H2

Action of air: It burns with oxygen and PRODUCES phosphorus pentoxide.

4PH3 + 8 O2 → P4O10 + 6H2O

Uses

Smoke screens

When PH3 burns it produces smoke which is dense enough to serve as smoke screens.

Holme’s signal: Containers which have a perforated bottom and a hole at the top are filled with calcium phosphide and calcium carbide. These are thrown into the sea. Water enters the container through the bottom and reacts with calcium carbide and calcium phosphide to give acetylene and phosphine. Phosphine gets ignited spontaneously as it comes in contact with air and also ignites acetylene.

Thus a bright red FLAME is produced which is accompanied by huge smoke due to the BURNING of phosphine. This serves as a signal to the approaching ships.

Ca3P2 + 6H2O → 2 PH3 ↑ + 3Ca(OH)2

CaC2 + 2H2O → C2H2 ↑ + Ca(OH)2

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HERE IS THE ANSWER

The TWO components of the solution are :-

➡SOLVENT: the component of the solution which is present in LARGE proportion is called solvent .

➡Solute: main component of the solution which is present in the small proportion is called solute .

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Gold NUMBER is a term used in colloidal CHEMISTRY. It is DEFINED as the minimum amount of protective colloid in milligrams which prevents a colour CHANGE from red to violet of 10ml goldsol by the addition of 1 ml of 10%NaCl solution.

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Mass of solvent = 500G

Mass of solute= ( needed to be FIND out )

Mass by mass percentage = 2.38%

Mass by mass percentage = Mass of solute / mass of solution × 100

Mass of solution = solute + solvent
( 500g + solute )

( solute ) / ( 500 + solute ) × 100 = 2.38

100solute = 2.38 ( 500 + solute )

100solute = 1190 + 2.38 solute

97.62 solute = 1190

Solute= 12.2g

Hope it helps

It is because, the sodium bicarbonate and sodium CARBONATE both are base and ALCOHOLS are NEARLY neutral compounds. Being base NaHCO3 and Na2CO3 react with acidic SUBSTANCES like CARBOXYLIC acids react with these substances

<P>Work, W, is Power, P, multiplied by time, t. The work done by the ENGINE in time t is THUS W = P t.

The work energy principle is that the work done on a system is EQUAL to the change in energy, ΔE, of the system.

Since there is no potential energy in this PROBLEM, the change in energy is just the change in kinetic energy.

That is ΔE = (1/2) m v2 - 0 = (1/2) m v2.

So (1/2) m v2 = P t and thus t = m v2 / (2 P)

The VALENCY of SULPHUR in H2S is 2

Peptization is the process responsible for the formation of stable dispersion of COLLOIDAL particles in dispersion medium. In other WORDS it may be defined as a process of CONVERTING a precipitate into colloidal SOL by shaking it with dispersion medium in the presence of small AMOUNT of electrolyte.

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Hi,

The spin MAGNETIC MOMENT is calculated by given below formula :

where n is number of unpaired ELECTRON.

Electronic configuration of SCANDIUM : [Ar] 3d​1 4s2

Electronic configuration of Sc+3 : ​[Ar] 3d​0 4s0

So, number of unpaired electron in Sc+3 is zero.

The spin only  magnetic moment of Sc+3 is zero.

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Measurement is the assignment of a number to a CHARACTERISTIC of an object or event, which can be COMPARED with other OBJECTS or events. The scope and application of measurement are dependent on the context and DISCIPLINE

Calcium starts floatingbecause the bubbles of hydrogen gas which are FORMED during the reaction stick to the surface of the metal and hence caclium FLOATS on WATER.

The required equation of the given reaction is:-

Fe2O3 + 3CO -----> 2Fe + 3CO2

From the equation we can see that,

1 MOLE of Fe2O3 -----> 3moles of CO2

Avogadro’s Law states that one mole of any dry GAS occupies 22.4L of volume at STP.

So, 3 MOLES of CO2 would occupy -----> (22.4 * 3) = 67.2L of volume

Hence, 67.2L of CO is needed for 1 mole of Fe2O3 to be REDUCED completely.

2Ag2O => 4Ag + O2

2Ag2CO3 => 4Ag + 2CO2 + O2 (rarely form HYDROXIDE)

2AgNO3=> 2AG + 2NO2 + O2 ....(best REACTION for this question)

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PLZZ mark it as brainlist

For DISCHARGING of metal the reaction is :M3+ + 3e- => M

Thus 1 mol of the metal is deposited by 3F = 3×96500 C = 289500

CCHARGE on 1.81×1023 electrons = 1.602×10-19 ×1.81​×1023 C = 2.9×104 C289500 C deposit = 1 mol of metal

Thus 2.9×104 C will deposit = 1289500×2.9×104moles metal = 0.100 moles0.100 moles = 1 g metal

Thus atomic mass of metal = 10 g/mol

According to Bohr's theory, the formula for calculating the POTENTIAL ENERGY of Hydrogen like species is −27.2(z2/n2)eV−27.2(z2/n2)eV

where z is the atomic number and N is the SHELL number.

For first shell of hydrogen atom put n=1 and z=1. You will get PE=−27.2eVPE=−27.2eV

PS PE is twice of KE (which has positive sign) in magnitude.

here is your ANSWER i HOPE it will HELP you.

SOLID STATE -

• The intermolecular force of attraction between particles is high as compared to LIQUIDS and gases.

• Solids have definite volume and shape.

• Solids are rigid and non-compressible.

• Solids have high density(except ice).

• Solids do not DIFFUSE easily.

• Solids do not TEND to flow.

LIQUIDS STATE -

• The intermolecular force of attraction between particles is high as compared to gases and LESS than solids.

• Liquids have definite volume but not definite shape.

• Liquids are not rigid and non-compressible.

• Liquids have high density than gases but less than solids.

• Liquids diffuse very slowly.

• Liquids tend to flow.

GASEOUS STATE -

• The intermolecular force of attraction between particles is very less.

• Gases do not have definite volume nor definite shape.

• Gases are not rigid and they are compressible.

• Gases have the lowest density than solids and liquids.

• Gases diffuses at a fast rate.

• Gases tend to flow.

So, water exists as a LIQUID at ROOM temperature with a high BOILING POINT. Sulphur is less electronegative than oxygen, and the S-H bond is much less polar than the O-H bond. Hence, there is no hydrogen bonding in hydrogen sulphide, and it normally exists as agas with discrete H2S molecules.

Hi.
It is the LOWEST whole no ratios of ions that represent in an IONIC COMPOUND OKE.
its useful for U

Sodium carbonate, USED to dissolve in water for washing and cleaning. LIKE SURF EXCEL, Tide etc

HEY !!

DIAMOND

• Diamond is very hard.
• It has high density.
• It is a bad CONDUCTOR of electricity but good conductor of heat than graphite.
• It possesses THREE dimensional net work structure.
• Chemical reactivity is low.
• Carbon undergoes sp³ hybridisation.
• C--C bond length is 154 pm.

GRAPHITE

• Graphite is soft.
• It has relatively low density.
• It is good conductor of heat and electricity.
• It possesses a sheet TYPE structure.
• Chemical reactivity is high.
• Carbon undergoes sp² hybridisation.
• C--C bond length 142 pm.

GOOD LUCK !!

Because the distilled water is a PURE form of water,it is neutral and it doesn't have any H+ IONS where as rain water is IMPUTE form of water,it show ACIDIC CHARACTER and contaion H+ ions

Answer:

0.4 MOLAR

Explanation:

molar MASS of NAOH = 40

Molarity= mass/molar mass *1000/volume in ML

= 4/40 *1000/250

=0.1*4

= 0.4 M

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Wurtz reaction is usually the first 'name reaction' one comes across in organic chemistry.

It provides a method for the synthesis of higher alkanes from alkyl halides by treating the latter with metallic sodium in dry ETHER.For instance, ETHANE can be obtained by treating methyl bromide with sodium in ether.

                          2CH3Br + 2Na = C2H6 + 2NaBr

Two molecules of the alkyl HALIDE condense into a larger alkane molecule with the elimination of the halogen atoms as sodium halide.

If two different alkyl halides are taken together, a mixture of three alkanes will be obtained. Thus, if both methyl and ethyl iodides are reacted with sodium, along with PROPANE, ethane and butane are also produced.

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HERE IS YOUR ANSWER

One mole of nitrogen GAS occupies 22.4 L of volume.

So let us first find out the number of MOLES.......
So N2 = 2*14 = 28 g/mol.

So 2.8 g of N2 CONTAINS
(2.8 / 28 )moles = 0.1 mole.

So the gas will occupy a volume of 0.1 * 22.4 = 2.24 L of volume.

THANK YOU

No.of mole=MASS in gm÷molecular mass

The pinacol–pinacolone rearrangement is a METHOD for converting a 1,2-diol to a CARBONYL COMPOUND in organic chemistry. The 1,2-rearrangement takes PLACE under acidic conditions

Hey Mate, Here's your Answer
To Extinguish the fire on clothes the best remedy is to roll the body of the victim with a thick and warm blanket
Due to WARMTH and increased pressure and the blockage of Oxygen the fire will have no SURFACE area to SPREAD and also Oxygen can't PROTECT it.
I HOPE it will help you

Ammonium ion (NH4+) is a COLOURLESS CATION and it is not a REPRESENTATIVE element

HELLO !!

●●●●●●●●●●●●●●

The DIFFERENT zones present in a candle flame are as follows.

1.  Innermost zone or the luminous zone( Black color )

2.  MIDDLE zone( YELLOW color )

3.  Outer zone or the non-luminous zone ( blue in color )

The outer zone is the hottest zone.

The innermost is the least hot zone .

●●●●●●●●●●●●●●●●

Hope it helps U !!

☺☺

(A) FE2O3 + 2AL ⇨ 2Fe + AL2O3
(Exothermic, DISPLACEMENT reaction)
(B) 2KI + Cl2 ⇨ 2KCl + I2
(Displacement reaction)

The MONOMERS of BAKELITE are PHENOL and Formaldehyde.

Structures are in the ATTACHMENT below↓↓

Hope it HELPS!!

SEDIMENTATION-it us the process of settling down heavier INSOLUBLE PARTICLES from a mixture
EG-even we mix sand and water in a beaker and leave the apparatus for some time the sand in the beaker will come down as it is heavier than water and settle down in beaker
DECANTATION-the process of transferring clear LIQUID with disturbing the sediments
EG-follow the same example given above but decant the liquid from the beaker to another beaker
hope my ANSWER helped you!!!

"BROMINE"

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Ammonia (NH3) is a weak BASE, which does not have hydroxyl group in its formula but itgives OH- ions when it reacts with WATER

Both as it ABSORBS HEAT to BURN and RELEASES heat after BURNING

First understand that we can only calculate energy of single ELECTRON species (charged atom) .As you know Be3+ has one electron only . we can calculate energy in n th orbit = -13.6 ×Z2/n2 where Z is atomic number and n is the number of the orbit . first excited state MEANS 2nd orbit .Z of Beryllium is 4. so energy =-13.6 ×16/4 = -54.4 EV sorry I didn't mention the unit earlier please MARK me as brainliest

Option c. 3s2 3p3...because here its SAID B has ea -60 kj. so it must be stable CONFIGURATION. we know stable configurated atoms does not WANT other electrons

The ELECTRONIC configuration of Be is 2S2, Since it has completely filled outer shells which is a stable configuration. It becomes ENERGETICALLY unfavourable to remove or ADD an electron and it has positive electron gain enthalpy.

Similarly, Ne is a noble gas and FULLY filled outer shell thus its electron gain enthalpy is positive.

TAKE a pen and paper and read the QUESTION and SOLVE it

+1(of H)+5(N)-6(of O*3)

SO YOUR ANSWER WILL BE 0

AS VALENCY IS THE COMBINIG CAPACITY AND THIS IS NOT APPLICABLE FOR COMPOUNDS