Explain the difference between atom and element

Answer:

Fluorite

What is Fluorite? Fluorite is an important industrial mineral composed of calcium and fluorine (CaF2). It is used in a wide variety of chemical, metallurgical, and ceramic processes

Answer:

0.768g of Fe are in the tablet = 38.4% by mass of Fe in the tablet

Explanation:

The balanced redox equation of Fe²⁺ with KMnO₄ in acidic medium is:

5Fe²⁺ + MnO₄⁻ + 8H⁺ → 5Fe³⁺ + Mn²⁺ + 4H₂O

Where 5 moles of Fe²⁺ react per mole of KMnO₄

The moles required of KMnO₄ are:

27.50cm³ * (1dm³ / 1000cm³) = 0.0275dm³ * (0.100mol / dm³) = 0.00275mol KMnO₄

Moles of Fe²⁺ are:

0.00275mol KMnO₄ * (5 moles Fe²⁺ / 1mol KMnO₄) = 0.01375moles of Fe²⁺

In grams (Molar mass Fe: 55.845g/mol):

0.01375moles of Fe²⁺ * (55.845g/mol) =

And percentage is:

0.768g Fe / 2.000g * 100 =

Answer:

B. Be, Mg, Ca, Sr

Explanation:

Be, Mg, Ca, Sr are parts of the alkaline Earth metal family/group. So they are the second most reactive elements following behind alkali metals. Furthermore, Be, Mg, Ca, Sr all have 2 valence electrons that lose them to form cations. They have low melting points, low boiling points, can conduct electricity, have high malleability and ductility.

Hope it helped!

Answer:

Introduction

As a diligent student of chemistry, you will likely encounter tons of reactions that occur in aqueous solution (perhaps you are already drowning in them!). When ions are involved in a reaction, the equation for the reaction can be written with various levels of detail. Depending on which part of the reaction you are interested in, you might write a molecular, complete ionic, or net ionic equation.

Definitions of molecular, complete ionic, and net ionic equations

A molecular equation is sometimes simply called a balanced equation. In a molecular equation, any ionic compounds or acids are represented as neutral compounds using their chemical formulas. The state of each substance is indicated in parentheses after the formula. [Huh?]

Let's consider the reaction that occurs between \text{AgNO}_3AgNO

3

​

start text, A, g, N, O, end text, start subscript, 3, end subscript and \text{NaCl}NaClstart text, N, a, C, l, end text. When aqueous solutions of \text{AgNO}_3AgNO

3

​

start text, A, g, N, O, end text, start subscript, 3, end subscript and \text{NaCl}NaClstart text, N, a, C, l, end text are mixed, solid \text{AgCl}AgClstart text, A, g, C, l, end text and aqueous \text{NaNO}_3NaNO

3

​

start text, N, a, N, O, end text, start subscript, 3, end subscript are formed. Using this information, we can write a balanced molecular equation for the reaction:

\text{AgNO}_3(aq) + \text{NaCl}(aq) \rightarrow \text{AgCl}(s) + \text{NaNO}_3(aq)AgNO

3

​

(aq)+NaCl(aq)→AgCl(s)+NaNO

3

​

(aq)start text, A, g, N, O, end text, start subscript, 3, end subscript, left parenthesis, a, q, right parenthesis, plus, start text, N, a, C, l, end text, left parenthesis, a, q, right parenthesis, right arrow, start text, A, g, C, l, end text, left parenthesis, s, right parenthesis, plus, start text, N, a, N, O, end text, start subscript, 3, end subscript, left parenthesis, a, q, right parenthesis

[What kind of reaction is this?]

If we could zoom in on the contents of the reaction beaker, though, we wouldn't find actual molecules of \text{AgNO}_3AgNO

3

​

start text, A, g, N, O, end text, start subscript, 3, end subscript, \text{NaCl}NaClstart text, N, a, C, l, end text, or \text{NaNO}_3NaNO

3

​

start text, N, a, N, O, end text, start subscript, 3, end subscript. Since \text{AgNO}_3AgNO

3

​

start text, A, g, N, O, end text, start subscript, 3, end subscript, \text{NaCl}NaClstart text, N, a, C, l, end text, and \text{NaNO}_3NaNO

3

​

start text, N, a, N, O, end text, start subscript, 3, end subscript are soluble ionic compounds, they dissociate into their constituent ions in water. For example, \text{NaCl}NaClstart text, N, a, C, l, end text dissociates into one ion of \text{Na}^+Na

+

start text, N, a, end text, start superscript, plus, end superscript for every ion of \text{Cl}^-Cl

−

start text, C, l, end text, start superscript, minus, end superscript; these ions are stabilized by ion-dipole interactions with the surrounding water molecules. [I don't get it!]

Image of crystalline sodium chloride next to image of chloride and sodium ions dissociated in water. Each chloride ion is interacting with multiple water molecules through the positive dipole of the water, and each sodium ion is interacting with water molecules through the negative dipole of the water.

Image of crystalline sodium chloride next to image of chloride and sodium ions dissociated in water. Each chloride ion is interacting with multiple water molecules through the positive dipole of the water, and each sodium ion is interacting with water molecules through the negative dipole of the water.

Sodium chloride dissociates into sodium and chloride ions in water, and these ions become solvated by the highly polar water molecules. Image credit: "Salts: Figure 1" by OpenStax Anatomy and Physiology, CC-BY-NC-SA 4.0.

From the molecular formula, we can rewrite the soluble ionic compounds as dissociated ions to get the complete ionic equation:

\text{Ag}^+(aq) + \blueD{{\text{NO}_3}^-(aq)} + \maroonD{\text{Na}^+(aq)} + \text{Cl}^-(aq) \rightarrow \text{AgCl}(s) + \maroonD{\text{Na}^+(aq)} + \blueD{{\text{NO}_3}^- (aq)}Ag

+

(aq)+NO

3

​

−

(aq)+Na

+

(aq)+Cl

−

(aq)→AgCl(s)+Na

+

(aq)+NO

3

​

−

​

−

(aq)

​

+

Na

+

(aq)

​

+Cl

−

(aq)→AgCl(s)+

Na

+

(aq)

​

+

NO

3

​

−

(aq)

​

Considering the solution of mole fraction, molality and molarity, you obtain that:

(a) the mole fraction of thiophene in the solution is 0.039.

(b) the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].

(c)  the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].

You know that:

The molar fraction is a way of measuring the concentration that expresses the proportion in which a substance is found with respect to the total moles of the solution.

Being the molar mass of each compound equals to:

the number of moles of each compound can be calculated as:

The total moles is obtained from the addition of the moles of the solute (C₄H₄S) and the solvent (C₇H₈):

total moles = moles C₄H₄S + moles C₇H₈ = 0.096 moles + 2.35 moles = 2.45 moles

Then, the mole fraction of thiophene in the solution can be calculated as:

[tex]mole fraction of thiophene=\frac{0.096 moles}{2.45 moles}[/tex]

Solving:

mole fraction of thiophene= 0.039

Finally, the mole fraction of thiophene in the solution is 0.039.

Molality is the ratio of the number of moles of any dissolved solute to kilograms of solvent.

The Molality of a solution is determined by the expression:

[tex]Molality=\frac{number of moles of solute}{kilograms of solvent}[/tex]

In this case, you know:

Replacing:

[tex]Molality C_{4} H_{4}S =\frac{0.096 moles}{0.21675 kg}[/tex]

molality C₄H₄S= 0.4429 [tex]\frac{moles}{kg}[/tex]

Finally, the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].

Molarity is the number of moles of solute that are dissolved in a certain volume and is determined by the following expression:

[tex]Molarity=\frac{number of moles of solute}{volume}[/tex]

Assuming that the volumes of solute and solvent are additive, you can add the volume of C₄H₄S and C₇H₈.

But first, you need yo know the volume of C₄H₄S, which can be calculated from the mass and density:

[tex]Volume C_{4} H_{4}S =8.10 grams\frac{1 mL}{1.065 grams}[/tex]= 7.606 mL= 0.007606 L

Then, the total volume of the solution is calculated as:

total volume of the solution= volume C₇H₈ + volume C₄H₄S

total volume of the solution= 0.250 L + 0.007606 L = 0.257606 L

So, the molarity of thiophene in the solution can be calculated as:

[tex]Molarity C_{4} H_{4} S=\frac{number of moles of C_{4} H_{4} S}{totalvolumeof the solution}[/tex]

Replacing:

[tex]Molarity C_{4} H_{4} S=\frac{0.096 moles}{0.257606 L}[/tex]

Solving:

Molarity C₄H₄S= 0.373 [tex]\frac{moles}{L}[/tex]

Finally, the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].

In summary, you get:

(a) the mole fraction of thiophene in the solution is 0.039.

(b) the molality of thiophene in the solution 0.4429 [tex]\frac{moles}{kg}[/tex].

(c)  the molarity of thiophene in the solution is 0.373[tex]\frac{moles}{L}[/tex].

Learn more about

Answer:

So we are given with the mass while we are asked for the amount of volume. So this means, we must need an information on the density. From literature, the density of human fat is 0.918 g/cm³. Convert grams to lb by the conversion that 1,000 g = 2.2 lbs.

Density = 0.918 g/cm³ * (2.2 lbs/1,000 g) = 0.0020196 lb/cm³

Volume = Mass/Density = 12.2 lb / 0.0020196 lb/cm³

Volume = 6,040.8 cm³

Answer:

Hydrogen

Explanation:

Answer:

fewest; the same significant figures with; measured numbers.

Explanation:

Without mincing words let us dive straight into the solution to the above question. In order to be able to use the significant figures properly one must know the rules attached to it uses. This is so, because they contributes to the precision of measurements.

When performing multiplication or division calculation, the number of significant figures in the answer[result] will be determined by the one with the smallest number of significant figure in the problem. Therefore, if we have 6.56 which is three[3] significant figures and 1.2 which is two[2] significant figures, then the number of significant figures will be two[2].

6.56 × 1.2= 7.872 = 7.9[ to 2 significant figures].

Answer:

67g/mol

Explanation:

The given compound is:

          NH₄NO₃ :

Problem here is to find the molar mass of the compound.

 Now;

The molar mass is the sum of the atomic masses of the elements in the compound.

   Atomic mass of N  = 14g

   Atomic mass of H  = 1g

   Atomic mass of O  = 16g

So;

   Molar mass = 14 + 4(1) + 1 + 3(16) = 67g/mol

Answer:

the answer is 80.0 grams per mole

Explanation:

Answer:

One electron per single hydrogen atom.

Explanation:

Hello!

In this case, given the reaction:

[tex]H_2+O_2\rightarrow H_2O[/tex]

Whereas we can identify the following half-reaction for hydrogen:

[tex]H_2^0\rightarrow H_2^+[/tex]

Whereas we see that each single hydrogen atom gains one electron in order to go from 0 to +1, which is also related to an oxidation half-reaction.

Best regards!

Answer:

Cyclopropane has a planar carbon back bone while propane does not

Explanation:

We have to recognize that in straight chain saturated organic compounds, carbon atoms have a tetrahedral geometry. Each carbon atom is bonded to four other atoms.

However, carbon atoms in cyclic compounds are also sp3 hybridized with each carbon bonded to only four other atoms but the ring system is highly strained.

Cyclopropane is a necessarily planar molecule with a bond angle that is far less than the expected tetrahedral bond angle due to strain in the molecule. Hence, the carbon atoms may have have a "planar backbone".

Answer:

A or C

Explanation:

Answer: It is D.

Explanation: Edge 2021

Answer:

Gravitational force between two objects depends on: a. The weight of the objects c. The mass of each object b. The distance between the objects d. Both b and c Please select the best answer from the choices provided A B C D

✓d

Answer:

Chemical formula of the compound = K₂O

Explanation:

Given:

Number of potassium cation = 2

Number of oxygen anion = 1

Cross valency

Symbol of potassium = k

Symbol of oxygen = o

So;

Chemical formula of the compound = K₂O

Shure what you need help with

Answer:

0.266 grams of calcium sulfate

Explanation:

We can calculate the mass of calcium sulfate added using the given volume and concentration of the solution:

First we convert 600.0 mL to L ⇒ 600.0 mL equals 0.6000 L (600 ÷ 1000).

0.444 g/L * 0.6000 L = 0.266 g

Thus the answer is 0.266 grams of calcium sulfate.

Answer: Coefficient 0

subscript for V 2

subscript for O 5

Explanation: yes

There is no coefficient in V₂O₅ and the subscript of vanadium V is 2 and the subscript of oxygen is 5.

Vanadium pentoxide is an ionic compound formed by donating electrons from the vanadium metal to oxygen.  The chemical formula of vanadium pentoxide is V₂O₅.

The chemical formula of a compound is written in terms of the chemical symbol of each constituent elements and the number of their atoms. The number of atoms is written as subscript for the chemical symbols.

In V₂O₅, there are are 2 vanadium atoms and 5 oxygen atoms. Coefficients are numbers prior to the formula in reaction. Here there is no coefficient and the subscript for V is 2 and that of O is 5.

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Answer:

2.343 g of HEPES sodium salt is needed.

Explanation:

So, from the question above we have the following parameters which is going to help in solving this particular question.

The number of moles = 90mM, the pH = 7.50, FW for the HEPES sodium salt = 260.31, and the volume of HEPES sodium salt required = 100mL.

Therefore, the amount of HEPES sodium salt required to make the buffer = 260.31 × 9 × 0.001 = 2.343 grams of HEPES sodium salt is needed in 10mL.

Answer:

How can we make use of acids or bases to remove heavy metals from soils? We can remove heavy metals from soil by adding acid and catching the solution that drains through. Acids can react with metals turning metalic compounds which can be dissolved by water and washed away. Improve crop yields?

Explanation:

Answer: 12.2 moles

Explanation:

7.36x10^24/6.02214076x10^23 = 12.2 moles of free oxygen atoms

H2O as an oxidant only

Given

Reaction

2 Na + 2 H2O → 2 NaOH + H2

Required

The function of water in the equation

Solution

Water : oxidizing agent

Na : reducing agent

Na⁰ → Na⁺ (oxidation)

H⁺- → H⁰ (reduction)

Acids and bases according to Bronsted-Lowry

Acid = donor (donor) proton (H⁺ ion)

Base = proton (receiver) acceptor (H⁺ ion)

If water is acting as an acid it should only give 1 H +, so that becomes:

H₂O (l) ⇔ OH⁻ (aq) not H₂

Answer:

Its particles are evenly distributed.

Explanation:

Solutions are homogenous mixtures of solutes and solvents. In a solution the solute particles are evenly distributed in the solvent.

Here are some characteristics of solutions:

A characteristic of a solution is that its particles are evenly distributed.

A characteristic of a solution is that its particles are evenly distributed. In a solution, the solute (substance being dissolved) is uniformly distributed and mixed with the solvent (the substance doing the dissolving) at the molecular or ionic level.

The particles of the solute become thoroughly dispersed and do not settle out over time. Solutions are generally clear and do not scatter light, unlike suspensions or colloids which may exhibit light scattering due to the presence of larger particles.

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Answer:

False

Explanation:

Mixtures are impure substances.

There are two types of mixtures based on the number of coexisting phases.

Homogeneous mixtures have their constituents existing in one single phase. The components are evenly spaced.

Heterogeneous mixtures have their constituents existing in at least two different phases. Therefore, they are unevenly spaced due to the phases present within the mixture.

Answer: a. Millimeter

Explanation:

A paperclip is a small device or instrument that can be used to hold the papers or stack of papers together. The length of the paperclip can be measured using millimeter. It is equal to the thousands of meters. The millimeter is a dimension which is used to measure the very small length objects which have visible scale distances and length.

Decimeter can be used to measure the length of the object smaller than paperclips. Meter and kilometers are used for objects and distances larger than paperclip.

Answer:

K₂CrO₅

Explanation:

The empirical formula is the simplest formula of a compound. To find the empirical formula, we follow the procedure below:

Elements                         Potassium                 Chromium         Oxygen

Mass                                  6.52                             4.34                  5.34

Molar mass                          39                               60                      16

Number of moles             6.52/39                     4.34/60             5.34/16

                                             0.167                          0.072              0.333

Divide through by

the smallest                      0.167/0.072             0.072/0.072          0.333/0.072

                                            2.3                               1                                4.6

                                             2                                 1                                  5

Empirical formula K₂CrO₅

A. They are the same

Given

C3H6 and C4H8

Required

The percent compositions

Solution

%C = 3.12/42 x 100% = 85.71%

%H = 6.1/42 x 1005 = 14.29%

C₄H₈(MW=56 g/mol)

%C = 4.12/56 x 100% = 85.71%

%H = 8.1/56 x 100%=14.29%

So they are the same, because mol ratio of C and H in both compounds is the same, 1: 2

Answer:

D.

Explanation:

INCREASE OF SOLAR WINDS When the sun is more active

Answer: