3. Calculate the answers to the appropriate number of significant figures. e) 43.678 x 64.1 = f) 1.678/0.42 =

Answer:

Atomic Number. 15=phosphorus

Valency=3

So, Oxide=P203

Answer:

On heating, the van der Waals dispersion forces existing then will easily break as it has a low boiling point and sublimates into gas. On heating iodine in the test tube, iodine evolves as violet fuming gas.

Explanation:

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]

Answer:

See explanation

Explanation:

TLC is a chromatographic method in which the solute is spotted on a plate and the plate is placed in an air tight chamber containing a solvent. The solvent is maintained below the level of the spot. The capillary movement of the solvent through the plate achieves the required separation.

If two spots have Rf values of 0.25 and 0.26 respectively and then the plate was removed from the developing chamber, subsequently, the residual solvent was allowed to evaporate from the plate, and then the plate was returned to the developing chamber.

It will be observed after the second development is complete that the new Rf values will be 0.50 and 0.52 respectively. It will just be as though the second chromatogram picked up from where the first chromatogram stopped.

Answer:

6.02 × 10²⁷ km

Explanation:

Step 1: Calculate the height of the stack of pennies

A penny has a thickness of approximately 1.0 mm. If you stacked Avogadro's number of pennies (6.02 × 10²³ pennies) one on top of the other on Earth's surface, the height of the stack of pennies would be:

6.02 × 10²³ pennie × 1.0 mm/1 pennie = 6.02 × 10²³ mm

Step 2: Convert 6.02 × 10²³ mm to kilometers

We will use the following conversion factors.

6.02 × 10²³ mm × 1 m/10³ mm × 1 km/10³ m = 6.02 × 10²⁷ km

Answer:

(a) The moles of CuSO₄ is 3.125 × 10⁻³ moles.

(b) The moles of Cu is 3.125 × 10⁻³ moles.

(c) The mass of Cu is 0.2 g.

Explanation:

Given:

Mass of CuSO₄ = 0.5 g

Molar mass of CuSO₄ = 160 g/mol

The given balanced chemical equation is:

[tex]2Al+3CuSO_4\rightarrow 3Cu+Al_2(SO_4)_3[/tex]

Part (a):

Calculating the moles of CuSO₄.

[tex]\text{Moles of } CuSO_4=\frac{\text{Mass of }CuSO_4}{\text{Molar mass of }CuSO_4}\\\\\text{Moles of } CuSO_4=\frac{0.5g}{160g/mol}\\\\\text{Moles of } CuSO_4=3.125\times 10^{-3}mol[/tex]

Thus, the moles of CuSO₄ is 3.125 × 10⁻³ moles.

Part (b):

Calculating the moles of Cu.

From the balanced chemical equation, we conclude that:

As, 3 moles of CuSO₄ reacts to give 3 moles of Cu

So, 3.125 × 10⁻³ moles of CuSO₄ reacts to give 3.125 × 10⁻³ moles of Cu

Thus, the moles of Cu is 3.125 × 10⁻³ moles.

Part (c):

Calculating the mass of Cu.

Mass of Cu = Moles of Cu × Molar mass of Cu

Molar mass of Cu = 64 g/mol

Mass of Cu = (3.125 × 10⁻³ mole) × (64 g/mol)

Mass of Cu = 0.2 g

Thus, the mass of Cu is 0.2 g.

Answer: hello some part of your question is missing below is the missing part

In an experiment to determine the % of ascorbic acid in Vitamin C Tablets by Titration with Potassium Bromate,

answer:

Oxidation half reaction of Vitamin C

Explanation:

The solution will turn cloudy dark purple even after reaching endpoint when allowed to settle with time. because of the Oxidation half reaction of Vitamin C. also during the Titration process few drops of starch solution will be added to help determine the endpoint of the experiment .

Answer:

2H2S(g) + 3O2(g) → 2H2O(g) + 2SO2(g) + 248kcal

Explanation:

The reaction of the problem occurs as follows:

H2S(g) + O2(g) → H2O(g) + SO2(g)

To balance the reaction we must balance oxygens:

H2S(g) + 3O2(g) → 2H2O(g) + 2SO2(g)

To balance the complete reaction:

2H2S(g) + 3O2(g) → 2H2O(g) + 2SO2(g)

As the energy is evolved, 124kcal are as product in the reactio per mole of H2S. As the balanced reaction contains 2 moles of H2S, the heat evolved is:

124kcal*2 = 248kcal:

2H2S(g) + 3O2(g) → 2H2O(g) + 2SO2(g) + 248kcal

And this is the balanced equation

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: 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:

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:

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:

C. The mass stays the same because the total number of atoms does not change

Explanation:

According to the law of conservation of matter/mass, matter cannot be created nor destroyed, hence, the amount of matter in the reactants must be the same amount in the products.

Using the photosynthetic reaction as a case study, carbon dioxide (CO2) and water (H2O) are the compounds that go into the reaction (reactants) while glucose and oxygen (O2) are the products of the reaction.

Using the law of conservation of matter to explain, the total mass of both the reactants and products stays the same because the total number of atoms does not change i.e. if 6 atoms of Carbon starts the reaction, 6 atoms of carbon will end it.

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:

Kf = 0.389.

Explanation:

Hello there!

In this case, it turns out possible for us to solve this problem by firstly writing the equilibrium chemical equation and equilibrium expression for the formation of this complex:

[tex]B+C\rightleftharpoons BC\\\\Kf=\frac{[BC]}{[B][C]}[/tex]

Thus, we firstly calculate the concentrations at equilibrium, knowing that the reaction extent in this case is 0.00500mol (same as the formed moles of BC):

[tex][B]=[C]=\frac{0.0350L*1.00mol/L-0.00500mol}{0.0700L} =0.429M[/tex]

[tex][BC]=\frac{0.00500mol}{0.0700L} =0.0714M[/tex]

And finally, the equilibrium constant:

[tex]Kf=\frac{0.0714}{[0.429][0.429]}\\\\Kf=0.389[/tex]

Regards!

Answer:

Glass 1

Explanation:

Molarity is measured in moles of substance per liter.

For the sake of calculations, let's say that each glass contains 1 mole of juice and 1 liter after it is divided between the glasses. If you add an equal amount of water to glass 1 ( another liter), you now have:

Glass 1 = 1 mole / 2 liters = 0.5 M

Glass 1 = 1 mole/ 1 liter = 1 M

So glass 1 will have a lower molarity

Answer:

the last one probably

Explanation:

Answer:

Explanation:

The solution of known concentration is expressed as molarity. Molarity is the mole fraction of solute (i.e. the dissolved substance) per liter of the solution, Molarity is also commonly called molar concentration.

Mathematically;

[tex]\mathtt{Molarity = \dfrac{moles \ of \ solute}{ liters \ of \ solution}}[/tex]

To copy and complete the road map from the given question, we have the following array:

      Volume A (L)

               ↓

d. multiplied by the molarity of A

               ↓

          moles A

               ↓

b. multiplied by the moles of B / moles of A

               ↓

         moles B

               ↓

c. divided by the molarity of B

               ↓

        volume B (L)

Answer:

a) [NOCl] = 0.968 M

[NO] = 0.032M

[Cl²] = 0.016M

b) [NOCl] = 1.992M

[NO] = 0.008 M

[Cl2]  = 1.004 M

Explanation:

Step 1: Data given

Temperature = 35°C = 308K

K = 1.6 × 10^-5

Step 2: The reaction

2 NOCl(g) ⇌ 2 NO(g) + Cl2(g)

For 2 moles NOCl we'll have 2 moles NO and 1 mol Cl2

Step 3

a. 2.0 mol pure NOCl in a 2.0 L flask

Concentration at the start:

Concentration = mol / volume

[NOCl] = mol / volume

[NOCl] = 2.0 / 2.0 L

[NOCl] = 1.0 M

[NO] = 0 M

[Cl] = 0M

Concentration at the equillibrium

[NOCl] = 1.0M - 2x

[NO] = 2x

[Cl2]= x

K = [Cl2][NO]² / [NOCl]² = 1.6*10^-5

1.6*10^-5 = ((2x)² * x) / (1.0-2x)²

x = 0.016

[NOCl] = 1.0 -  2*0.016 = 0.968 M

[NO] = 2*0.016 = 0.032M

[Cl²] = 0.016M

b. 2.0 mol NOCl and 1.0 mol Cl2 in a 1.0 L flask

Concentration at the equillibrium

[NOCl] = 2.0 mol / 1.0 L = 2.0 M

[NO] = 0 M

[Cl2]= 1.0 mol / 1.0 L = 1.0 M

Concentration at the equillibrium

[NOCl] = 2.0M - 2x

[NO] = 2x

[Cl2]= 1.0 + x

K = [Cl2][NO]² / [NOCl]² = 1.6*10^-5

1.6 *10^-5 = (2x)²*(1.0+x) / ((2.0-2x)²)

1.6 *10^-5= (2x)² * 1 )/2.0²

1.6 *10^-5= 4x² / 4 = x²

x = [tex]\sqrt{1.6 *10^-5}[/tex] = 4.0*10^-3

[NOCl] = 2.0 - 2*0.004 = 1.992M

[NO] = 2*0.004 = 0.008 M

[Cl2] = 1+ 0.004M = 1.004 M

Answer:

It is so because heat is flowing from hot body to cold body, and there is no direct contact between the body. It explains correctly the mode of transmission of thermal energy through the process of radiations.

Explanation:

Fun fact:

How does thermal energy transfer by radiation?

Radiation. All objects transfer energy to their surroundings by infrared radiation . The hotter an object is, the more infrared radiation it gives off. No particles are involved in radiation, unlike conduction.

Answer:

The netto reaction equation is:

2 OH- + 2H+ = 2 H2O  

So the answer is 2 moles.

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:

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:

Calcium Oxide is a drying agent, hence it dehydrates the reaction to give pure solid Iron ( III ) chloride, which cannot be done by calcium chloride.

It preferred to use calcium oxide rather than calcium chloride in preparation of iron (III) chloride because Calcium Oxide is a drying agent, hence it dehydrates the reaction to give pure solid Iron ( III ) chloride, which cannot be done by calcium chloride.

A process such as a chemical reaction that removes water.The atoms which constitute the molecule of water that is removed.

Hence,It preferred to use calcium oxide rather than calcium chloride in preparation of iron (III) chloride because Calcium Oxide is a drying agent,

Thus, it dehydrates the reaction to give pure solid Iron ( III ) chloride, which cannot be done by calcium chloride.

Learn  more about reactions here ;

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Explanation:

ethoxypropane

Ch3-ch2-o-ch2-ch2-och3

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