Why are half-reactions used in redox reactions?

Answer:

Na2CO3 + CaCl2 → CaCO3 + 2 NaCl

Explanation:

A double displacement reaction is a type of metathesis reaction in which two reactants exchange ions to form two new compounds. Double displacement reactions usually involve reacting two soluble salts in aqueous solution resulting in the formation of two products: a soluble salt and an insoluble salt that is produced as a precipitate.

If the reaction of two soluble compounds does not produce a precipitate, the reaction does not result in the formation of a product as basically, all the ions are mixed together in the reaction vessel.

From the given reactions above:

1. 3 KBr + AlPO4 → K3PO4 + AlBr3

The reaction does not proceed to product formation as the two products are all soluble salts.

2. Na2CO3 + CaCl2 → CaCO3 + 2 NaCl

The reaction occurs as one of the products, CaCO3 is insoluble as is produced as a precipitate.

3. NH4OH + KCl → KOH + NH4Cl

The reaction does nott occuras the products are all soluble in water.

4. ZnCl2 + Mg2SO4 → ZnSO4 + MgCl2

The reaction does not occur as the products are all soluble in water.

Answer:

I'm pretty sure its D

Explanation:

It says the best that explains. D states that when it has less energy that it the molecules will collide. And they would to make a liquid. So thats why its D.

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

Answer:

133.34 g/moles

Explanation:

but to make life easy it could be 133.4 g/ moles as well

Answer: 0.144 moles. :)

Explanation:

The number  of  moles of NaCl that are contained in 50.0 mL of 2.50 M NaCl is 0.125 moles

Using this formula

Molarity=Moles of solute/Liters of solution

First step is to convert 50.0 mL to Liters

Litres=50.0 ml×1 L/1000 ml

Litres=0.05 L

Now let determie the number of moles of NaCl

2.50M=moles/0.05

moles=2.50M(0.05)

moles = 0.125 moles of NaCl

Inconclusion The number  of  moles of NaCl that are contained in 50.0 mL of 2.50 M NaCl is 0.125 moles

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Answer:

They all have a certain amount of protons electrons and neutrons.

Answer: Skeletal System

Explanation: Sense It's Sending up a signal up Joaquin's spinel cord It must be traveling threw his skeletal system

Answer:

its the nervous system because by tapping the knee, it will send a nerve down the neuron, through the mylein sheath and through the axon terminals to the receptors, which will recieve the nerve's signal and send it to the brain through the spinal cord in simple terms.

Answer:

formation of shadow is right

Answer:

correct answer is D

Explanation:

When you see a shadow, it is directly behind the object.

So, litmus paper is a qualitative tool for assessing the acidity or basicity of a substance (usually a solution). In general, blue litmus turns red in the presence of an acid, and red litmus turns blue in the presence of a base. They can't really tell you much more than that.

The solutions that are most likely acids are those that turn blue litmus red and do not evoke a color change in red litmus. A solution that turns red litmus blue or does not evoke a color change in blue litmus is likely not an acid. Using these criteria, solutions 4 and 7 are most likely acids since they both turn blue litmus red (and they cause no color change in red litmus).

The correct answer choice would thus be D.

Answer:

The light is transmitted through the curtain.

Explanation:

I believe this might be the answer, please comment if it’s incorrect

wish in new Explanation:

Answer: b

Explanation: jk

Answer:

B i think

Explanation:

Answer:

15.4%

Explanation:

If Ka = 0.54 mM = 1.51x10⁻⁵

Then;

C₄H₈O₂               -------->            C₄H₇O₂⁻          +           H⁺

I                    0.54x10⁻³                             0                                0

E                   0.54x10⁻³(1-x)                      0.54x10⁻³x                0.54x10⁻³x

Recall that x is the percentage degree of dissociation

From the ICE table;

Ka = [C₄H₇O₂⁻] [ H⁺]/[C₄H₈O₂]

1.51x10⁻⁵=(0.54x10⁻³x) (0.54x10⁻³x)/ 0.54x10⁻³(1-x)  

1.51x10⁻⁵ = 0.54x10⁻³x^2/1-x

1.51x10⁻⁵(1-x) = 0.54x10⁻³x^2

1.51x10⁻⁵ - 1.51x10⁻⁵x = 0.54x10⁻³x^2

Hence;

0.54x10⁻³x^2 + 1.51x10⁻⁵x - 1.51x10⁻⁵=0

x^2 + 0.028x - 0.028 = 0

Solving the quadratic equation here;

x = 0.154 or −0.182

Ignoring the negative result, x = 0.154

Hence, fraction of butanoic acid that is in the dissociated form in this solution = 15.4%

Answer: Ba(NO3)2(aq) + H2O(l)

Explanation:

Answer:

-security hardware

- artificial intelligence

wifi, internet, phones, voice assistants, drones.

Answer:

0.4 M

Explanation:

The process that takes place in an aqueous K₂HPO₄ solution is:

First we calculate how many K₂HPO₄ moles are there in 200 mL of a 0.2 M solution:

Then we convert K₂HPO₄ moles into K⁺ moles, using the stoichiometric coefficients of the reaction above:

Finally we divide the number of K⁺ moles by the volume, to calculate the molarity:

Answer:

soil

Explanation:

Answer:

The food chain begins with the sun: plants get their energy by photosynthesizing sunlight into energy, and then herbivores eat those plants to get their energy. Carnivores who then eat the herbivores are getting that sunlight passed along from sun to plant to herbivore to carnivore.

Answer:

the reducing agent is Bromine

The oxidation state of an element is calculated by subtracting and the total sum of oxidation states of all the individual atom (excluding the one that has to be calculated) from total charge on the molecule. Bromine is the reducing agent in the following reaction.

Oxidation state of an element is a number that is assigned to an element in a molecule that represents the number of electron gained or lost during the formation of that molecule or compound.

The ionic equation is given as

2 Br⁻(aq) + H[tex]_2[/tex]O[tex]_2[/tex](aq) + 2 H⁺(aq) → Br[tex]_2[/tex](aq) + 2 H[tex]_2[/tex]O(l)

The oxidation state of bromine on reactant side is -1 while on product side it is 0 so, oxidation state of bromine has increased by 1 so,  bromine is oxidized. If it is oxidized that means it must have reduced someone. So, bromine is acting as a reducing agent.

Therefore, bromine is the reducing agent in the given reaction.

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Answer:

The vegetative parts includes the roots, stems,leaves and the reproductive parts include flowers. ... The vegetative parts can reproduce new plants by the process of vegetative propagation but the reproductive parts cannot produce new plants directly instead they produce precursor of new plants that are seeds or fruits.

Answer:

tissues,organs, organelles

Answer:

Water can be used for direct and indirect purposes. Direct purposes include bathing, drinking, and cooking, while examples of indirect purposes are the use of water in processing wood to make paper and in producing steel for automobiles. The bulk of the world's water use is for agriculture, industry, and electricity.

Explanation:

Answer:

water is used for drinking, bathing, cooking, agriculture etc

Answer:

It is clear from the above food chain that the grass occupies the first topic level which consists of producers. The second tropic level consist of primary consumers which is Insect. And the Frog assign the Third tropic level of food chain consisting of secondary consumers.Explanation:

Answer:

i cant see the whats in the picture