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3 years ago

Select the statement that is incorrect. View Available Hint(s) Select the statement that is incorrect.

Chemistry

1 answer:

Novosadov [1.4K]3 years ago

4 0

Answer:

(b). All carbohydrates have the general formula $C_{n}(H_{2}O)_{n}$

Explanation:

Carbohydrates, more commonly known as sugars, are made up of carbon, oxygen, and hydrogen atoms. As mono-saccharide is known as the smallest unit of a carbohydrate . Two monosaccharides make up a disaccharide, and many monosaccharides make up a polysaccharide. Disaccharides and polysaccharides can be hydrolyzed back into the individual monosaccharide units.

As we know that the carbohydrate is always represented as

$(CH_{2}O)_{n}$ ,

where n is any number between three and eight.

Hence, the option (b) is incorrect.

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If all other variables remain unchanged, what happens to the output force when the area of the input piston is doubled?

mars1129 [50]

Answer:

1250N

Explanation:

This question is based on pascal's Law.

So By Pascal's Law

therefore =force on input piston =25N

= Force or weight on output person.

therefore after putting the values we get,

= (25x 1500)/30

=1250N

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3 years ago

If you were asked to convert 4.2 × 1022 atoms of aluminum to moles, which of the following should you use for the conversion?

DanielleElmas [232]

4.2×1022NA N_{A} is the avagadro number

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3 years ago

KFell Fe"(CN), + e + Nat → KNaFe'Fe(CN)6

Alinara [238K]

Answer:

Most common oxidation states: +2, +3

M.P. 1535º

B.P. 2750º

Density 7.87 g/cm3

Characteristics: Iron is a gray, moderately active metal.

Characteristic reactions of Fe²⁺ and Fe³⁺

The [Fe(H2O)6]3+ ion is colorless (or pale pink), but many solutions containing this ion are yellow or amber-colored because of hydrolysis. Iron in both oxidation states forms many complex ions.

Aqueous Ammonia

Aqueous ammonia reacts with Fe(II) ions to produce white gelatinous Fe(OH)2, which oxidizes to form red-brown Fe(OH)3:

Fe2+(aq)+2NH3(aq)+3H2O(l)↽−−⇀Fe(OH)2(s)+2NH+4(aq)(1)

Fe3appt.gif

Aqueous ammonia reacts with Fe(III) ions to produce red-brown Fe(OH)3:

Fe3+(aq)+3NH3(aq)+3H2O(l)↽−−⇀Fe(OH)3(s)+3NH+4(aq)(2)

Fe3bppt.gif

Both precipitates are insoluble in excess aqueous ammonia. Iron(II) hydroxide quickly oxidizes to Fe(OH)3 in the presence of air or other oxidizing agents.

Sodium Hydroxide

Sodium hydroxide also produces Fe(OH)2 and Fe(OH)3 from the corresponding oxidation states of iron in aqueous solution.

Fe2+(aq)+2OH−(aq)↽−−⇀Fe(OH)2(s)(3)

Fe4appt.gif

Fe3+(aq)+3OH−(aq)↽−−⇀Fe(OH)3(s)(4)

Fe4bppt.gif

Neither hydroxide precipitate dissolves in excess sodium hydroxide.

Potassium Ferrocyanide

Potassium ferrocyanide will react with Fe3+ solution to produce a dark blue precipitate called Prussian blue:

K+(aq)+Fe3+(aq)+[Fe(CN)6]4−(aq)↽−−⇀KFe[Fe(CN)6](s)(5)

Fe5a1ppt.gif

With Fe2+ solution, a white precipitate will be formed that will be converted to blue due to the oxidation by oxygen in air:

2Fe2+(aq)+[Fe(CN)6]4−(aq)↽−−⇀Fe2[Fe(CN)6](s)(6)

Fe5a2ppt.gif

Many metal ions form ferrocyanide precipitates, so potassium ferrocyanide is not a good reagent for separating metal ions. It is used more commonly as a confirmatory test.

Potassium Ferricyanide

Potassium ferricyanide will give a brown coloration but no precipitate with Fe3+. With Fe2+, a dark blue precipitate is formed. Although this precipitate is known as Turnbull's blue, it is identical with Prussian blue (from Equation 5).

K+(aq)+Fe+2(aq)+[Fe(CN)6]3−(aq)↽−−⇀KFe[Fe(CN)6](s)(7)

Fe5b.gif

Potassium Thiocyanate

KSCN will give a deep red coloration to solutions containing Fe3+:

Fe+3(aq)+NCS−(aq)↽−−⇀[FeNCS]+2(aq)(8)

Fe5cppt.gif

No Reaction

Cl−, SO2−4

7 0

3 years ago

Wich statement best describes the difference between strong nuclear forces and weak nuclear forces

Vika [28.1K]

Answer: option D is right.

Explanation: There are four types of fundamental forces in nature.These are named as gravitational force,electromagnetic force,strong nuclear force and weak nuclear force.

As per the question we have to understand the role of strong nuclear force and weak nuclear force.

An atom consists of a nucleus surrounded by extra nuclear part consisting of electrons in various orbits.The nucleus contains two basic particles called protons and neutrons .Protons are positively charged while neutrons are neutral.Protons being positively charged will impart repulsive force on each other and may come out of the nucleus.But the nucleus is stable.That is due to the strong nuclear force.

Strong nuclear force is a spin dependent and charge independent force which comes into existence due to the mutual interaction of gluons which binds the protons and neutrons .Hence it is attractive in nature.It's 100 times more stronger than electromagnetic force also.

Weak nuclear force comes into existence during radio -active decay .This force is due to the exchange of ' w' and 'z' bosons[the particles like protons and neutrons having integral or zero spin] which are heavier in nature.The role of it is to change protons into neutrons and vice versa.Its a short range force.

Hence the option D is right.

4 0

3 years ago

Think of an everyday activity where removal of one of the products helps the reaction to faster in forward direction?

elena55 [62]

Answer:

Cooking with open, exposed flame to prevent build up of CO₂ which will extinguish the fire

Explanation:

In the cooking process whereby food is heated by the combustion of cooking gas as follows;

C₄H₁₀ (g) + (13/2)O₂ → 4CO₂(g) + 5H₂O(g), ΔH = -2658 kJ·mol⁻¹

The product of the combustion must be allowed to escape freely to allow for more reactant molecules of oxygen and butane to effectively combine.

Whereby, the CO₂ is allowed to remain and accumulate at the reaction site, the CO₂ displaces the oxygen and reduces the butane such that as the CO₂ builds up without removal, the CO₂ and butane will left in the mixture while the fire is extinguished.

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3 years ago