Phosphorus pentachloride, PCl5, a white solid that has a pungent, unpleasant odor, is used as a catalyst for certain organic reactions. Calculate the number of moles in 38.7 g of PCl5.

Answer:

A. Wax drips down the side of a lot candle.

Explanation:

The chemical change from solid to liquid. This is a combustion reaction, so carbon dioxide gas and water vapour is also produced but you can't see them

Answer:

A. Wax drips down the side of a lot candle.

Explanation:

Answer:

Eu(ClO3)3

Explanation:

The chlorate ion is written as follows, ClO⁻ ₃. We can see from this that the ion is univalent.

From the formula, Eu203, it is easy to see that the europium ion is trivalent.

Hence, when a compound is formed between the europium ion and chlorate ion, the compound will be written as Eu(ClO3)3.

This is so because, when ionic compounds are formed, there is an exchange of valence between the ions in the compound. This gives the final formula of the ionic substance.

Answer:

A physical change is a change in form.

A Chemical change is a change in materials.

Explanation:

Example of a physical change would be an ice cube meting.

Example of a chemical change would be mixing food coloring into a cup of water.

Answer:

Concentration of unknown solution is 0.0416 M

Explanation:

As we know  

Absorbance is equal to the product of molar absorptivity of KMnO4 m, path length and concentration

From the given set of graphical data, it is clear that the absorbance vs concentration is a straight line.  

From the graph, we can obtain-  

Y = 5.73 X – 0.0065

Absorbance = 0.232

0.232 = 5.73 X – 0.0065

X = 0.0416  

Concentration of unknown solution is 0.0416 M

Answer:

Explanation:

Let us define oxidation and reduction.

Oxidation and reduction deal with the transferring of electrons between reactants. The reactant that loses electrons is oxidized, while the reactant that gains electrons is reduced.

In an oxidation-reduction reaction, the substance oxidized always loses electrons and the correct option is option D.

An oxidation-reduction (redox) reaction is a type of chemical reaction that involves the transfer of electrons between species. It consists of two half-reactions: an oxidation half-reaction, where a species loses electrons and increases its oxidation state, and a reduction half-reaction, where a species gains electrons and decreases its oxidation state.

In an oxidation half-reaction, the species that is oxidized is called the reducing agent or the electron donor, as it donates electrons. In a reduction half-reaction, the species that is reduced is called the oxidizing agent or the electron acceptor, as it accepts electrons.

Thus, the ideal selection is option D.

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Answer:

3.93g are recovered

Explanation:

Pb(NO3)2 reacts with KCl as follows:

Pb(NO3)2 + 2KCl → 2KNO3 + PbCl2

To solve this question we need to find the moles of each reactant in order to find the limiting reactant:

Moles Pb(NO3)2 -Molar mass: 331.2 g/mol-

5.72g * (1mol/331.2g) = 0.01727 moles

Mole KCl -Molar mass: 74.5513g/mol-

5.85g * (1mol/74.5513g) = 0.07847 moles

For a complete reaction of 0.07847 moles of KCl are required:

0.07847 moles KCl * (1mol Pb(NO3)2 / 2mol KCl) = 0.03923 moles Pb(NO3)2

As there are just 0.01727 moles, Pb(NO3)2 is limiting reactant. Assuming 100% of yield:

Moles PbCl2 = Moles Pb(NO3)2

Mass PbCl2 -Molar mass: 278.1g/mol-

0.01727 moles * (278.1g / mol) = 4.80g

As percent yield is 81.9% = 0.819, the mass of PbCl2 recovered was:

4.80g * 0.819 = 3.93g are recovered

Answer:

Hi so your answer is that to helping fix the climate change you have to : speak up , power your home with renewable engery , reduce water waste , dont waste food , and finally invest energy .

Explanation:

Really hope i helped , have a nice day :)

Answer:

we can reduce air pollution,which is one of the main cause of climate change.Climate change is not a hoxe if it is not attending the upcoming generations will suffer greatly.

Answer:

b. 0.27 M ammonia + 0.38 M ammonium nitrate.

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to bear to mind the fact that buffest must be prepared by using either of the following pairs:

weak acid/conjugate base

weak base/conjugate acid

So that the pH might be set constant. In such a way, since a. shows two salts, c. a strong acid with a neutral base, d, shows two acids and e. a strong base with a neutral base, we infer the correct buffer is b. 0.27 M ammonia + 0.38 M ammonium nitrate because it has a weak base (ammonia) and its conjugate acid, ammonium.

Regards!

Answer:

Limiting reagent is the potassium carbonate.

Percent yield of calcium carbonate is: 39.3 %

Explanation:

The reaction is:

CaCl₂ + K₂CO₃ → CaCO₃ + 2KCl

Formula for percent yield is:

(Produced yield / Thoeretical yield) . 100

Firstly we determine the moles of each reactant, in order to say what is the limiting reagent: ratio is 1:1.

1 mol of chloride need 1 mol of carbonate.

14.570 g . 1 mol /110.98 g = 0.131 moles of CaCl₂

12.285 g . 1 mol / 138.2g = 0.0889 moles of carbonate.

Limiting reagent is carbonate. For 0.131 moles of CaCl₂ we need the same amount of carbonate and we have less moles.

Ratio is also 1:1, with calcium carbonate.

1 mol of potassium carbonate produces 1 mol of calcium carbonate

then, 0.0889 moles will produce the same amount of CaCO₃

We convert moles to mass: 0.0889 mol . 100.08g /mol = 8.89 g

That's the theoretical yield; to find the percent yield:

(3.494 g / 8.89g) . 100 = 39.3%

Answer:

2-ethyl-3-methylbut-2-ene

Explanation:

The whole idea of IUPAC nomenclature is to devise a universally accepted system of writing the name of a compound from its structure.

According to IUPAC nomenclature, the root of the compound is the longest carbon chain. The substituents are named in alphabetical order and in such a way as to give each one the lowest number. The position of the functional group is indicated accordingly.

For the compound in question, its correct IUPAC name is 2-ethyl-3-methylbut-2-ene.

Answer:

d,e

Explanation:

Answer:

482

Explanation:

Answer:

Atomic Number. 15=phosphorus

Valency=3

So, Oxide=P203

Answer:

C) Polar

Explanation:

The correct answer is polar

The attraction of sodium and chloride ions by the water is mediated by the polar nature of water. Thus, option C is correct.

The polarity is given as the formation of the partial positive and negative charge over the species in the ionization process.

Water molecule is having one hydrogen bounded with 2 oxygen atoms, and oxygen being more electronegative develops a partial negative charge, while hydrogen develops a partial positive charge.

The positive charge hydrogen and the negative charge oxygen attracts the opposite charge sodium and chloride ions. Thus, the attraction is mediated due to the polar nature of water. Hence, option C is correct.

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Answer:

electrovalent

NaCl

Lithium Carbonate

ammonium phosphate

aluminium floride

potassium hydride

covalent

methane

benzene

carbon iv oxide

hydro flouride

hydro chloride

Answer:

The netto reaction equation is:

2 OH- + 2H+ = 2 H2O  

So the answer is 2 moles.

Answer:

531.6g

Explanation:

Total moles of glucose in this case is: 886/180= 4.922 (mole)

For every 1 mole glucose we get 6 mole water

-> Mole of water is: 4.922 * 6= 29.533 (mole)

weight of water is 18. Therefore, total weight of water that we will have from 886g of glucose are: 25.933*18= 531.6g

Answer:

The answer is "5.4".

Explanation:

[tex]BoH + HCL =BCL +H_2o \\\\At eq \\\\N_1V_1=N_2V_2 \\\\v_2=20 \ ml\\\\[BCL]=\frac{20 \times 0.08}{20+20}=0.04\\\\pH = \frac{1}{2} [pkw - pk_b - \log e]\\\\pk_b = 2 pH - Pkw + \Log C\\\\pK_b=5.4[/tex]

Chemistry and chemical reactions are not just limited to the laboratories but also the world around you.

Chemistry in Food Production:

Plants produce food for themselves through photosynthesis; which is a complex chemical reaction in itself. The chemical reaction that takes place in photosynthesis is the most common and vital chemical reaction. 

6 CO2 + 6 H2O + light → C 6H12O6 + 6 O2

Chemistry in Hygiene:

Right before you consume your food, you make it a point to wash your hands with soap. Isn’t it? The cleaning action of soap is based on its ability to act as an emulsifying agent. Soaps are fatty acids salts of sodium or potassium; produced by a chemical reaction called saponification. Soaps interact with the grease or oil molecule, which, in turn, results in a cleaner surface.

The Chemistry of an Onion:

Ever wondered why you shed tears while chopping an onion? This also happens because of the underlying chemistry concepts. As soon as you slice an onion, sulfenic acid is formed from amino acid sulfoxides. Sulfenic acid is responsible for the volatile gas, propanethiol S-oxide, that stimulates the production of tears in the eyes.

Chemistry in Baking:

Who does not like to eat fluffy freshly baked bread? Baking soda is an efficient leavening agent. The addition of baking soda to food items before cooking leads to the production of carbon dioxide (CO2); which causes the foods to rise. This whole process of rising of baked good is called chemical leavening.

Chemistry in Food Preservatives:

In case you ever read the ingredients on the bottle of ketchup, jams or pickles, you might be surprised to see a never-ending list of chemicals. What are they? These chemicals are called food preservatives; which delay the growth of microorganisms in foods. The chemical food preservatives not only prohibit the growth of bacteria, virus, fungi but also hinder the oxidation of fats, which is responsible for making the foods rancid. The most common chemical food preservatives are sodium benzoate, sorbic acid, potassium sorbate, calcium sorbate, sodium sorbate, propionic acid, and the salts of nitrous acid.

Chemistry in Digestion

The moment you put food in your mouth, a number of different chemical reactions start in your digestive tract. Saliva contains the enzyme amylase, which is responsible for breaking down carbohydrates, the stomach starts producing hydrochloric acid, the liver releases bile and the list of compounds released during digestion goes on. How do they work? All these enzymes undergo chemical reactions so that proper digestion, as well as assimilation of the food, occurs.

The Working of a Sunscreen

Before going out on a sunny day, you make it a point to wear sunscreen. Even the principle, behind the working of a sunscreen, has a chemistry background. The sunscreen uses a combination of organic and inorganic compounds to act as a filter for incoming ultraviolet rays. Sunblocks, on the other hand, scatter away UV light; so that it is unable to penetrate deep into the skin. Sunblocks contain complex chemical compounds like zinc oxide or titanium oxide, which prevent the UV rays to invade deeper into the skin.

Chemistry in Rust Formation

With time, your iron instruments start developing an orange-brown flaky coating called rust. The rusting of iron is a type of oxidation reaction. The atoms in the metal iron undergo oxidation and reduction; causing rusting. The formation of verdigris on copper and the tarnishing of silver are also the other everyday examples of chemical reactions. The chemical equation underlying rusting is:

Fe + O2 + H2O → Fe2O3. XH2O

Hope it helps.

Answer:

còmo supòtànté insígídà pàtàtàk

Answer:

gamma rays > X-rays > ultraviolet radiation > visible light > infrared > radio waves.

Explanation:

Electromagnetic waves are those waves that require no material medium for propagation. They can travel through space and they all move at the speed of light.

Electromagnetic waves are composed of both electric and magnetic fields which are mutually at right angles to each other.

The order of decreasing energy of electromagnetic waves is;

gamma rays > X-rays > ultraviolet radiation > visible light > infrared > radio waves.

Explanation:

the answer is in the image above

Answer: The molar concentration of acetic acid in the vinegar is 0.539 M.

Explanation:

The formula used is:

[tex]M_1V_1=M_2V_2[/tex]

where,

[tex]M_1[/tex] and [tex]V_1[/tex] are the concentration and volume of base.

[tex]M_2[/tex] and [tex]V_2[/tex] are the concentration and volume of an acid.

Given:

Molar concentration of NaOH = 0.1798 M

Volume of NaOH = 30.01 mL

Volume of acetic acid = 10.0 mL

Now putting all the given values in the above formula, we get:

[tex]M_1V_1=M_2V_2\\\\0.1798M\times 30.01mL=M_2\times 10.0mL\\\\M_2=0.539M[/tex]

Thu, the molar concentration of acetic acid in the vinegar is 0.539 M.

Answer and Explanation:

The reaction is in the gas phase, so the equilibrium constant is expressed in terms of the partial pressures (P) of the products and reactants, as follows:

[tex]Kp = \frac{P^{2}_{SO_{3} } }{P_{SO_{2}} ^{2}P_{O_{2}} }[/tex]

We have the following data:

P(SO₃) = 2.6 atm

P(O₂) = 0.43 atm

We need Kp for this reaction. We can assume that in Appendix 4 we found that Kp = 7 x 10²⁴.

Then, we introduce the data in the equilibrium constant expression to calculate the partial pressure f SO₂ (PSO₂), as follows:

[tex]P_{SO_{2} } = \sqrt{\frac{P_{SO_{3} } ^{2} }{Kp P_{O_{2} } } } = \sqrt{\frac{(2.6 atm)^{2} }{(7 x 10^{24)}(0.43 atm) } } = 1.5 x 10^{-12} atm[/tex]

Therefore, the partial pressure of SO₂ is 1.5 x 10⁻¹² atm (for the given Kp).

Answer:

A form of energy that can be used by cells.

Explanation:

Answer:

Kc = 0.630

Explanation:

The equilibrium of the thiocyanate system occurs as follows:

FeSCN²⁺(aq) ⇄ Fe³⁺(aq) + SCN⁻(aq)

And equilibrium constant, kc, is:

Kc = [SCN⁻] [Fe³⁺] / [FeSCN²⁺]

Replacing with the gven concentrations:

Kc = 0.639M*0.494M / 0.501M

Answer: The value of [tex][H_{3}O^{+}][/tex] is 0.0012 M and [tex][OH^{-}][/tex] is [tex]1.02 \times 10^{-14}[/tex].

Explanation:

pH is the negative logarithm of concentration of hydrogen ion.

It is given that pH is 2.89. So, the value of concentration of hydrogen ions is calculated as follows.

[tex]pH = - log [H^{+}]\\2.89 = - log [H^{+}]\\conc. H^{+} = 0.0012 M[/tex]

The relation between pH and pOH value is as follows.

pH + pOH = 14

0.0012 + pOH = 14

pOH = 14 - 0.0012 = 13.99

Now, pOH is the negative logarithm of concentration of hydroxide ions.

Hence, [tex][OH^{-}][/tex] is calculated as follows.

[tex]pOH = - log [OH^{-}]\\13.99 = - log [OH^{-}]\\conc. OH^{-} = 1.02 \times 10^{-14} M[/tex]

Thus, we can conclude that the value of [tex][H_{3}O^{+}][/tex] is 0.0012 M and [tex][OH^{-}][/tex] is [tex]1.02 \times 10^{-14}[/tex].

Answer:

37.9% v/v

Explanation:

Since both the alcohol and solution are presumed to be liquid, this concentration can be expressed as a volume concentration (or % v/v):

volume concentration = volume of solute / volume of solution

[tex]\% v/v = 55/145= 0.379[/tex]