What is true about atomic radius trends on the periodic table?
A. Atomic radius decreases along periods and decreases down groups.
B. Atomic radius decreases along periods and increases down groups.
C. Atomic radius increases along periods and decreases down groups.
D. Atomic radius increases along periods and increases down groups.
It is not b

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 =

The original concentration : 800%

Given

Diluted 1/40

Final concentration 20%

Required

The original concentration

Solution

Dilution is the process of adding solvent to get a more dilute solution.

The moles(n) before and after dilution are the same.

Can be formulated :

 n₁ = n₂

M₁.V₁ = M₂.V₂

diluted 1/40(dilution factor)⇒ V₁/V₂=1/40⇒V₂/V₁=40

M₂ = 0.2(20%)

Input the value for M₁ :

M₁=M₂ x (V₂/V₁)

M₁ = 0.2 x 40

M₂ = 8(800%)

=

Answer:

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Explanation:

)??

A scientific control is an experiment or observation designed to minimize the effects of variables other than the independent variable. This increases the reliability of the results, often through a comparison between control measurements and the other measurements.

Answer:

Hydrogen

Explanation:

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:

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)

​

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:

436.55841 grams.

Explanation:

The molecular formula for Iron(III) Iodide is FeI3. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Iron(III) Iodide, or 436.55841 grams.

You use the 1 / 436.55841 conversion rate. This is different for each element, according to the stoichiometry tables. Iron(II) oxide would be 2/3 of the 1/436.55841 conversion rate, that is, multiplying the fraction to denominator.

4 in hydrogen 4 in oxygen

Explanation:

hope this helps

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

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:

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: 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: 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:

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:

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

2265 g Fe₃O₄

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

[RxN - Balanced] Fe₃O₄ + 4H₂ → 3Fe + 4H₂O

[Given] 705.0 g H₂O

Step 2: Identify Conversions

[RxN] 4 mol H₂O → 1 mol Fe₃O₄

Molar Mass of H - 1.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of Fe - 55.85 g/mol

Molar Mass of H₂O - 2(1.01) + 16.00 = 18.02 g/mol

Molar Mass of Fe₃O₄ - 3(55.85) + 4(16.00) = 231.55 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 4 sig figs.

2264.74 g Fe₃O₄ ≈ 2265 g Fe₃O₄

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:

when the atom moves to the third energy level, its energy increases. However, when it goes back to the second energy level its overall energy decreases.

Explanation:

the smallest (or innermost) energy level has the least amount of energy and the largest (or outer most) level needs the most amount of energy. In order for the electron to move from one level to the other, it would need to match the energy of that level.

Which of the statements about liquids and gases are true?

The particles in liquids and gases can move past one another freely.

Which of the statements about liquids and gases are true?

Both liquids and gases have a definite volume.

The particles in liquids and gases can move past one another freely

Both liquids and gases have a definite shape.

Neither liquids nor gases have a definite shape.

The particles in liquids and gases can move past one another freely.

Answer:

We can find out what animals eat..and how long a food chain could get..?

Explanation:

Answer:

vgffffgggggvghvxgyfdgubvhumigrrdghg

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:

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

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:

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:

C = 18.29 g  

Explanation:

Given data:

Mass of beryllium needed = ?

Mass of nitrogen = 18.9 g

Solution:

Chemical equation:

3Be + N₂    →    Be₃N₂

now we will calculate the number of moles of nitrogen:

Number of moles = mass/molar mass

Number of moles = 18.9 g/ 28 g/mol

Number of moles = 0.675 mol

Now we will compare the moles of nitrogen and Be from balance chemical equation.

                     N₂        :       Be        

                       1          :       3

                  0.675       :      3/1×0.675 = 2.03 mol

Number of moles of Be needed are 2.03 mol.

Mass of Beryllium:

Mass = number of moles × molar mass

Mass = 2.03 mol ×   9.01 g/mol

Mass = 18.29 g