Redox reactions stand for oxidation/reduction reactions. True or false: an oxidation reaction is always paired with a reduction reaction.

The change in internal energy (ΔΕ) of a system : -8 kJ

The laws of thermodynamics 1 state that: energy can be changed but cannot be destroyed or created  

The equation is:  

 [tex]\tt \Delta U=Q+W[/tex]

Energy owned by the system is expressed as internal energy (U)  

This internal energy can change if it absorbs heat Q (U> 0), or releases heat (U <0). Or the internal energy can change if the system does work or accepts work (W)  

The sign rules for heat and work are set as follows:  

• The system receives heat, Q +  

• The system releases heat, Q -  

• The system does work, W -  

• the system accepts work, W +  

5 kJ of work is done on the system : W = +5 kJ

releases 13 kJ of energy to the surroundings : Q = -13 kJ

[tex]\tt \Delta E=-13+5=-8~kJ[/tex]

Answer:

Explanation:

The volume of a substance when given the density and mass can be found by using the formula

[tex]volume = \frac{mass}{density} \\[/tex]

From the question we have

[tex]volume = \frac{3.50}{5.61} \\ = 0.6238859...[/tex]

We have the final answer as

Hope this helps you

Answer:

53.5%

Explanation:

Step 1: Given data

Step 2: Calculate the mass corresponding to 0.00875 moles of KClO₃

The molar mass of KClO₃ is 122.55 g/mol.

0.00875 mol × 122.55 g/mol. = 1.07 g

Step 3: Calculate the percent by mass of KClO₃ in the mixture

We will use the following expression.

%m/m = mass of KClO₃/mass of the sample × 100%

%m/m = 1.07 g/2.00 g × 100%

%m/m = 53.5%

The percent by mass of KClO3 in the original mixture is 53.5%.

Since

The mass of the sample should be 2.00 g

Moles of KClO₃: 0.00875 mol

The molar mass of KClO₃ is 122.55 g/mol.

Now the mass is

= 0.00875 mol × 122.55 g/mol.

= 1.07 g

Now the percentage should be

= mass of KClO₃/mass of the sample × 100%

= 1.07 g/2.00 g × 100%

= 53.5%

hence, The percent by mass of KClO3 in the original mixture is 53.5%.

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Answer:

156.4g K

Explanation:

I'm not sure if it is correct but I think it should be this

What do we know so far?: 2K + 1Cl2 -> 2KCl, 2 mol of Cl2

What are we looking for?: #g of K

What is the ratio of K to Cl2?: 2:1

Set up equation: 2molCl2 x [tex]\frac{2mol K}{1 mol Cl2}[/tex]

Cancel unwanted units: 2 x [tex]\frac{2mol K}{1}[/tex]

Answer we got: 2 x 2mol K = 4mol K

Converting moles to grams: 4 x 39.1 (molar mass of K) = 156.4g K

Answer:

work out if it's either going to sink or float

Explanation:

this can be carried out by calculating the numbers

Answer:

[tex]\%m/m=14\%[/tex]

Explanation:

Hello!

In this case, since the molarity of magnesium chloride (molar mass = 95.211 g/mol) is 1.672 mol/L and we know the density of the solution, we can first compute the concentration in g/L as shown below:

[tex][MgCl_2]=1.672\frac{molMgCl_2}{L}*\frac{95.211gMgCl_2}{1molMgCl_2}=159.2\frac{gMgCl_2}{L}[/tex]

Next, since the density of the solution is 1.137 g/mL, we can compute the concentration in g/g as shown below:

[tex][MgCl_2]=159.2\frac{gMgCl_2}{L}*\frac{1L}{1000mL}*\frac{1mL}{1.137g}=0.14[/tex]

Which is also the by-mass fraction and in percent it turns out:

[tex]\%m/m=0.14*100\%\\\\\%m/m=14\%[/tex]

Best regards!

Answer:

Under balanced its motion under motion its s = d/t under s - d/t is time d = distance s= speed

Explanation:

Answer:

1.089%

Explanation:

From;

ν =1/2πc(k/meff)^1/2

Where;

ν = wave number

meff = reduced mass or effective mass

k = force constant

c= speed of light

Let

ν =1/2πc (k/meff)^1/2  vibrational wave number for 23Na35 Cl

ν' =1/2πc(k'/m'eff)^1/2 vibrational wave number for 23Na37 Cl

The between the two is obtained from;

ν' - ν /ν  = (k'/m'eff)^1/2 - (k/meff)^1/2 / (k/meff)^1/2

Therefore;

ν' - ν /ν = [meff/m'eff]^1/2 - 1

Substituting values, we have;

ν' - ν /ν = [(22.9898 * 34.9688/22.9898 + 34.9688) * (22.9898 + 36.9651/22.9898 * 36.9651)]^1/2  -1

ν' - ν /ν = -0.01089

percentage difference in the fundamental vibrational wavenumbers of 23Na35Cl and 23Na37Cl;

ν' - ν /ν * 100

|(-0.01089)|  × 100 = 1.089%

Answer:

1.089%

Explanation:

From;

ν =1/2πc(k/meff)^1/2

Where;

ν = wave number

meff = reduced mass or effective mass

k = force constant

c= speed of light

Let

ν =1/2πc (k/meff)^1/2  vibrational wave number for 23Na35 Cl

ν' =1/2πc(k'/m'eff)^1/2 vibrational wave number for 23Na37 Cl

The between the two is obtained from;

ν' - ν /ν  = (k'/m'eff)^1/2 - (k/meff)^1/2 / (k/meff)^1/2

Therefore;

ν' - ν /ν = [meff/m'eff]^1/2 - 1

Substituting values, we have;

ν' - ν /ν = [(22.9898 * 34.9688/22.9898 + 34.9688) * (22.9898 + 36.9651/22.9898 * 36.9651)]^1/2  -1

ν' - ν /ν = -0.01089

percentage difference in the fundamental vibrational wavenumbers of 23Na35Cl and 23Na37Cl;

ν' - ν /ν * 100

|(-0.01089)|  × 100 = 1.089%

Answer:

B

Explanation:

hydrogen only has one electron/molecule in it's only shell so it can get together and make a bond

Answer:

Empirical formula is C₂H₆S

Explanation:

Given data:

Percentage of hydrogen = 9.73%

Percentage of carbon = 38.66%

Percentage of sulfur = 51.61%

Empirical formula = ?

Solution:

Number of gram atoms of H = 9.73 / 1.01 = 9.6

Number of gram atoms of S = 51.61 / 32 = 1.6

Number of gram atoms of C = 38.66 / 12 = 3.2

Atomic ratio:

             C                      :      H              :         S

           3.2/1.6               :     9.6/1.6       :       1.6/1.6

            2                      :        6             :        1

C : H : S = 2 : 6 : 1

Empirical formula is C₂H₆S.

Answer: He theorized that all material bodies are made up of indivisibly small “atoms.” Aristotle famously rejected atomism in On Generation and Corruption. Aristotle refused to believe that the whole of reality is reducible to a system of atoms.

Explanation:

Aristotle disagreed with Democritus primarily on the nature of matter and the concept of atomism.

Democritus proposed the theory of atomism, suggesting that all matter is composed of indivisible and indestructible particles called atoms. He believed that atoms combine and interact to form different substances.

On the other hand, Aristotle rejected the notion of atomism and instead proposed a different theory of matter. According to Aristotle, matter is continuous and infinitely divisible. He believed that substances are composed of four primary elements - earth, air, fire, and water - which have different inherent properties and undergo transformations through the combination and separation of these elements.

Aristotle's disagreement with Democritus stemmed from their differing views on the fundamental nature of matter. While Democritus emphasized the discrete and fundamental nature of atoms, Aristotle emphasized the continuous and composite nature of matter. Their contrasting viewpoints reflected a broader philosophical divide between atomism and holism in ancient Greek philosophy.

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Answer:

sopas

Explanation:

lagyan mo ng condense

There is a golden role of solubility, polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, the  total mass of the soup is 2,060gram.

Solutions are a homogeneous mixture of two or more substances. A solution is a homogeneous mixture of solvent and solute molecules. Solvent is a substance that is in large amount in solution. solute is the substance which is in small amount in a solution. There are two types of mixture that is homogeneous and heterogeneous. Solution is a homogeneous solution.

mass of soup= mass of water+ mass of vegetables + mass of meat

mass of water=1,500 grams

mass of vegetables= 350 grams

mass of meat=210 grams

substituting all the values in the above equation, we get

mass of soup= 1,500 grams+ 350 grams + 210 grams

                      = 2,060gram

Therefore, the  total mass of the soup is 2,060gram.

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Answer:

[tex]K=0.14[/tex]

Explanation:

Hello!

In this case, for the undergoing chemical reaction, we can write the equilibrium expression via:

[tex]K=\frac{[SO_2][NO_2]}{[SO_3][NO]}[/tex]

Whereas the equilibrium concentration of both SO3 and NO are 2.55 M and 1.90 M respectively, it means that the extent of reaction [tex]x[/tex] is:

[tex]x=1.90M-1.20M=0.7M[/tex]

Because the equilibrium expression in terms of the reaction extent is:

[tex]K=\frac{x*x}{([SO_3]_0-x)([NO]_0-x)}[/tex]

It means that the concentration of SO3, NO, SO2 and NO2 at equilibrium are:

[tex][SO_3]=2.55M-0.70M=1.85M[/tex]

[tex][NO]=1.20M[/tex]

[tex][SO_2]=0.70M[/tex]

[tex][NO_2]=0.70M[/tex]

Thus, the equilibrium constant for such reaction is:

[tex]K=\frac{0.70*0.70}{1.85*1.90}\\\\K=0.14[/tex]

Best regards!

Molarity after dilution : 0.0058 M

The number of moles before and after dilution is the same  

The dilution formula

 M₁V₁=M₂V₂

M₁ = Molarity of the solution before dilution  

V₁ = volume of the solution before dilution  

M₂ = Molarity of the solution after dilution  

V₂ = Molarity volume of the solution after dilution

M₁=0.1 M

V₁=6.11

V₂=105.12

[tex]\tt M_2=\dfrac{M_1.V_1}{V_2}=\dfrac{0.1\times 6.11}{105.12}=0.0058~M[/tex]

Answer:

group 18

Explanation:

The noble gases (Group 18) are located in the far right of the periodic table and were previously referred to as the "inert gases" due to the fact that their filled valence shells (octets) make them extremely nonreactive

Answer:group 18

Explanation

Answer:

Glycogen: It is made up of a large chain of molecules. ...

Cellulose: The cell wall of the plants is made up of cellulose. ...

Starch: It is formed by the condensation of amylose and amylopectin. ...

Insulin: It is made up of a number of fructofuranose molecules linked together in chains.

Explanation:

Answer:

[tex]V = 0.117 \ L[/tex]

General Formulas and Concepts:

Chem

Explanation:

Step 1: Define

1.57 M KOH (potassium hydroxide)

10.3 g KOH

Step 2: Define conversions

Molar Mass of K - 39.10 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of H - 1.01 g/mol

Molar Mass of KOH - 39.10 + 16.00 + 1.01 = 56.11 g/mol

Step 3: Convert

[tex]10.3 \ g \ KOH(\frac{1 \ mol \ KOH}{56.11 \ g \ KOH} )[/tex] = 0.183568 mol KOH

Step 4: Solve for Volume

Step 5: Check

We are given 3 sig figs. Follow sig fig rules.

[tex]0.116922 \ L \approx 0.117 \ L[/tex]

Answer:

The center of the atom contains the nucleus so yes

Explanation:

Answer:

D

Explanation:

Answer:

[tex]E=9.62\times 10^{-21}\ J[/tex]

Explanation:

Given that,

The wavelength of a microwave is 7.42 mm or 0.00742 m

No. of photons, n = 359

We need to find the energy produced by this no of photons. It can be given by the formula as follows :

[tex]E=\dfrac{nhc}{\lambda}\\\\E=\dfrac{359\times 6.63\times 10^{-34}\times 3\times 10^8}{0.00742}\\\\=9.62\times 10^{-21}\ J[/tex]

or

[tex]E=9.62e^{-21}\ J[/tex]

So, the required energy is [tex]9.62\times 10^{-21}\ J[/tex].

Answer:

⬆️That guy deserves brainliest

Explanation:

Answer:

a. The carbon-carbon bond in ethane's the longest!)

Explanation:

Ethane is a chemical compound that is organic in nature. Its chemical formula is [tex]$C_2H_6$[/tex]. It has two carbon atoms and six of hydrogen atoms that is connected to the carbon atoms.

Ethane is odorless and colorless at the standard temperature and standard pressure.

The carbon to carbon atoms in ethane is connected by a single bond.

The length of single carbon-carbon bond is greater than carbon-carbon double bond and triple bond.

Thus, carbon-carbon bond length in ethane is the longest.

Answer:

The answer is

Explanation:

The number of molecules present can be found by using the formula

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

N = 4.21 × 6.02 × 10²³

We have the final answer as

Hope this helps you

Answer:

Metalloids and ions

Explanation:

Mercury is not solid at room temperature. (Metals)

Many nonmetals aren't good at conducting electricity. Oxygen for example. (Nonmetals)

Metalloids are always solid at room temp and are fair conductors. (Metalloids)

Ions are same as metalloids. (Ions)

PLS GIVE BRAINLIEST

Answer:

pH = 4.89

0.6171g of KOH must be added

Explanation:

Sodium acetate reacts with HCl producing acetic acid as follows:

NaC2H3O2 + HCl → HC2H3O2 + NaCl

That means the moles added of HCl are moles of acetic acid produced and moles of acetate are initial moles - moles of HCl

Moles HCl = Moles acetic acid:

0.204L * (0.452mol / L) = 0.0822 moles acetic acid.

Initial moles sodium acetate:

0.500L * (0.400mol / L) = 0.200 moles

Moles sodium acetate:

0.200 moles - 0.0822 moles = 0.1172 moles sodium acetate

The pH of this buffer (Mixture of a weak acid and its conjugate base) is obtained using H-H equation:

pH = pKa + log [A-] / [HA]

Where pH is pH of the buffer,

pKa is pKa of the buffer (4.74 for acetic acid)

[A-] Moles of sodium acetate -Conjugate base-

And HA moles of acetic acid -Weak acid-

pH = 4.74 + log [0.1172 moles] [0.0822 moles]

In 0.500L the moles of the buffer are:

0.500L * (0.200moles / 0.704L) = 0.142 moles of buffer

For a pH of 0.15 units more (4.89 + 0.15 = 5.04):

5.04 = 4.74 + log [Acetate] / [Acetic acid]

0.3 = log [Acetate] / [Acetic acid]

1.9953 = [Acetate] / [Acetic acid] (1)

And as:

0.142 = [Acetate] + [Acetic acid] (2)

Replacing (2) in (1):

1.9953 = 0.142 - [Acetic acid]  / [Acetic acid]

1.9953 [Acetic acid] = 0.142 - [Acetic acid]

2.9953 [Acetic acid] = 0.142 moles

[Acetic acid] = 0.0474 moles of acetic acid must remain after the addition of KOH.

In the beginning, moles of acetic acid are:

0.0822 moles * (0.500L / 0.704L) = 0.0584 moles.

That means moles added of KOH (Equal to moles of acetic acid that react) are:

0.0584 moles - 0.0474 moles = 0.0110 moles of KOH

In grams (Molar mass KOH = 56.1g/mol):

0.0110 moles KOH * (56.1g/mol) =

A weather front is a transition zone between two different air masses at the Earth's surface. Each air mass has unique temperature and humidity characteristics. Often there is turbulence at a front, which is the borderline where two different air masses come together. The turbulence can cause clouds and storms.

Answer:

Bromine is a very reactive element. While it is less reactive than fluorine or chlorine, it is more reactive than iodine. It reacts with many metals, sometimes very vigorously. For instance, with potassium, it reacts explosively.

Explanation:

Answer: Bromine is a high reactive element. While it is not as reactive as fluorine or chlorine, it is still more reactive than iodine. It reacts with many metals, and even sometimes very aggressively. For example, when mixed with potassium, it will explode.  

Explanation:

Answer:

The second answer

Explanation:

Phase changes is an example of physical change because it only changes the substance's appearance.

Answer: 1 and 4 are the answers

Explanation: because when you mix a sub since and it will have a chemical change