How can we write a chemical reaction that explains what happens during a chemical change?

The correct significant figures are;

a. (7.31 × 10⁴) + (3.23 × 10³) = 7.633 x 10⁴

b. (8.54 x 10⁻³) - (3.41 x 10⁻⁴) = 8.199 x 10⁻³

c. 4.35 dm x 2.34 dm x 7.35 dm = 74.81565 dm³

d. 4.78 cm + 3.218 cm + 5.82 cm = 13.818 cm

e. 38,736 km + 4784 km = 43,520 km

Significant figures are used to establish the number which is presented in the form of digits.

Solution of the given problems in correct significant figures;

a. (7.31 × 10⁴) + (3.23 × 10³) = 76,330 = 7.633 x 10⁴

b. (8.54 x 10⁻³) - (3.41 x 10⁻⁴) = 8.199 x 10⁻³

c. 4.35 dm x 2.34 dm x 7.35 dm = 74.81565 dm³

d. 4.78 cm + 3.218 cm + 5.82 cm = 13.818 cm

e. 38,736 km + 4784 km = 43,520 km

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The following are from uranium-234 to thorium-230. Alpha decay can be seen in nuclear processes.

Chemical processes entail transformations, turning reactants into products. On the basis of the kinds of alterations that are taking place throughout the reaction, fundamental chemical reactions can be divided into categories. There are five fundamental categories: single replacement, double replacement, combustion, and synthesis.

Understanding a substance's qualities is made easier by chemical reactions. We can learn about the chemical properties of a material by looking at how it interacts with other substances. An unknown sample can be recognized using these characteristics. We can learn about how the natural world functions by watching chemical processes.

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The outer electrons of potassium (K) are found in the fourth energy level, also known as the fourth electron shell.

Potassium has an atomic number of 19, indicating that it has 19 electrons. The electron configuration of potassium is \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^1\). In this configuration, the outermost electron of potassium is located in the 4s orbital, which corresponds to the fourth energy level.

The electronic structure of an atom describes the arrangement of electrons in its energy levels or electron shells. The outermost energy level, also known as the valence shell, is particularly important as it determines the chemical properties and reactivity of an element.

In the case of potassium, the outermost electron in the 4s orbital is involved in its chemical interactions and bonding behavior.

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Answer:

Proton

Explanation:

It has a positive charge

Answer:

electron

Explanation:

Answer:

true

Explanation:

Answer:

false

Explanation:

i took the test and got it right

Option A, which proposes that circadian rhythms help communities survive by enabling people to react more effectively to daily fluctuations, offers the most compelling explanation for these findings.

Five different cyanobacteria species, including two strains of Anabaena flosaquae, Aphanizomenon flosaquae, Microcystis aeruginosa, and Nodularia species, have been discovered as toxin makers. Hepatotoxins, neurotoxins, and lipopolysaccharide (LPS) endotoxins are the three primary categories of cyanobacterial toxins.

The simplest known species at this time are cyanobacteria, which are also the only prokaryotes known to possess a well-researched and reliable circadian clock. Synechococcus elongatus PCC 7942, a genetically tractable bacterium, has become a leading model system for research on the molecular foundations and control of the clock.

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Moles of AlCl_3

\(\\ \tt\hookrightarrow \dfrac{352}{133}=2.64mol\)

Now

\(\\ \tt\hookrightarrow 4.2=\dfrac{2.64}{V}\)

\(\\ \tt\hookrightarrow V=0.62L\)

Answer:

0.1715 atm

Explanation:

We use the Ideal gas equation to calculate this

Mathematically;

PV = nRT

rearranging, we have

P = nRT/V

from the question, we have

n = 0.002 moles

R = 0.082

T = 250 = 250 + 273 = 523 K

V = 500 ml = 500/1000 = 0.5 L

Plugging the values we have;

P = (0.002 * 0.082 * 523)/0.5

P = 0.1715 atm

The balanced symbol equation for the Haber process, which is the industrial method for producing ammonia, is N2 + 3H2 → 2NH3

A. The Haber process is the industrial method for producing ammonia, and the balanced equation for the reaction is:

N2 + 3H2 → 2NH3

The atom economy for a product is the percentage of the total mass of reactants that becomes the desired product. For ammonia, the atom economy can be calculated as follows:

Molar mass of NH3 = 14.01 + 3(1.01) = 17.04 g/mol

Atom economy of NH3 = (2 mol NH3 x 17.04 g/mol) / [(1 mol N2 x 28.02 g/mol) + (3 mol H2 x 2.02 g/mol)] x 100% = 34.0%

B. To calculate the theoretical yield of ammonia, we need to use the given mass of nitrogen and the stoichiometry of the balanced equation. The molar mass of nitrogen is 28.02 g/mol, so 27.3 g of nitrogen is equal to:

27.3 g / 28.02 g/mol = 0.974 mol N2

According to the balanced equation, 1 mole of N2 reacts with 3 moles of H2 to produce 2 moles of NH3. Therefore, the theoretical yield of ammonia is:

Theoretical yield of NH3 = (0.974 mol N2) x (2 mol NH3 / 1 mol N2) x (17.04 g/mol NH3) = 33.1 g NH3

C. The percentage yield of the reaction can be calculated by dividing the actual yield of ammonia by the theoretical yield, and then multiplying by 100%. The actual yield of ammonia is given as 29.9 g:

Percentage yield of NH3 = (29.9 g NH3 / 33.1 g NH3) x 100% = 90.4%

D. The percentage conversion of hydrogen can be calculated by dividing the mass of hydrogen used in the reaction by the mass of hydrogen that would have been used if all of it had been consumed in the reaction. The mass of hydrogen used is 10.4 g, and the mass of hydrogen that would have been used if all of it had been consumed in the reaction is:

1( mol H2 x 2.02 g/mol) x (0.974 mol N2 / 1 mol N2) = 1.98 g H2

Therefore, the percentage conversion of hydrogen is:

Percentage conversion of H2 = (10.4 g H2 / 1.98 g H2) x 100% = 525% (This result is not possible, as the percentage conversion cannot be greater than 100%. It is likely that there was an error in the calculation or in the data provided.)

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Answer:

D-the measure of temperature in a system

The atom economy is a measure of how effectively the reactants are used to produce the desired product. A higher atom economy indicates a more efficient reaction, as it means a larger percentage of the reactants contribute to the desired product.

In this reaction, the atom economy is 29.5%. This means that only 29.5% of the total mass of the reactants is converted into hydrazine, while the remaining mass contributes to the formation of sodium chloride and water. A higher atom economy would indicate a more efficient reaction, as it would mean a larger percentage of the reactants is converted into the desired product.

It is important to consider the atom economy in chemical reactions because it helps in evaluating the efficiency and sustainability of a process. Reactions with higher atom economies are preferred as they minimize waste and maximize the utilization of reactants.

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Answer: C

Explanation: Based on the periodic table, O is atomic number 8, which means it has 8 electrons. The first few atomic orbitals are 1s, 2s, and 2p.Each orbital can hold 2 electrons maximum, and there are 2l+1 of each type of orbital (s,p,d,f,g,...), where l=0 corresponds to an s orbital, l=1 means porbital, and so on. So, the configuration for neutral O atom is: 1s22s22p4. When oxygen gains two electrons, it acquires a charge of 2−. Therefore, the twoelectrons, which go into the highest-energy atomic orbitals, give you a new configuration of1s22s22p6for O2−, which is the same electron configuration as Ne. That is known as a noble-gas-like configuration, and in general it is stable if oxygen is like that in a compound (having 8 electrons in its 2s and 2p orbitals combined).

Answer:

the nature of the bond is covalent.

covalent bonds are bonds between 2 NON-METAL elements. since phosphorus and oxygen are both non-metals, the bond formed between them is covalent.

hope this answers your question!

Answer:

Explanation:

Here, we want to get the mass of carbon (iv) oxide produced

From the question, we have the balanced chemical reaction stating that 2 moles of oxygen molecule produced 1 mole of carbon (iv) oxide molecule

The number of moles of carbon (iv) oxide produced from 7.34 mol oxygen is thus:

1 mole of carbon (iv) oxide contains 44 g

The mass in 3.67 moles will be:

Therefore, it takes approximately 23.2 kJ of energy to boil 100 mL of water.

The correct answer is D. 100 mL × 1g divided by 1mL × 1mol divided by 18.02g × 4.186 kJ/mol = 23.2 kJ

To calculate the energy required to boil 100 mL of water, we need to use the specific heat capacity of water, which is approximately 4.186 J/g·°C. The molar mass of water is 18.02 g/mol.

First, we convert the volume of water from milliliters to grams:

100 mL × 1 g/1 mL = 100 g

Then, we calculate the number of moles of water:

100 g × 1 mol/18.02 g = 5.548 mol

Finally, we multiply the number of moles by the molar heat of vaporization of water, which is approximately 40.65 kJ/mol:

5.548 mol × 4.186 kJ/mol = 23.2 kJ

Therefore, it takes approximately 23.2 kJ of energy to boil 100 mL of water.

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Answer:

option . D

Increase in temperature

is an indicator of a chemical reaction

hope it helps

Answer:

answer is D

Explanation:

some signs of a chemical change are a change in colour and the formation of bubbles.

the five conditions of chemical change: colour change, formation of precipitate, formation of a gas ,odor change, temperature change.

I think it will use for you

The mass of KCl recovered can be less than the starting mass of KHCO3 due to several factors, such as:

1. Incomplete conversion: The reaction between KHCO3 and HCl to form KCl involves a stoichiometric ratio. If the reaction is not driven to completion or if there are side reactions or competing reactions, it may result in an incomplete conversion of KHCO3 to KCl. This would lead to a lower mass of KCl recovered compared to the starting mass of KHCO3.

2. Losses during the process: During the reaction and subsequent processes like filtration or drying, some of the product (KCl) or reactant (KHCO3) may be lost. Losses can occur due to physical losses like splattering or spilling, or chemical losses like volatilization of certain compounds.

3. Impurities or contaminants: The starting KHCO3 may contain impurities or contaminants that do not convert to KCl during the reaction. These impurities or contaminants can remain in the reaction mixture or be lost during subsequent purification steps, leading to a difference in the mass of KCl recovered.

It is important to ensure proper reaction conditions, efficient conversion, and minimize losses during handling and purification to achieve a higher recovery of the desired product.

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Answer:

See Explanation

Explanation:

The compound involved here is BF3(boron triflouride). The central atom is boron and it is surrounded by three fluorine atoms as shown in the image.

When a molecule has three electron domains in its structure, the molecule is trigonal planar. Hence, the molecular geometry of the compound is trigonal planar.

Answer

(d) i, ii, iii, iv

Explanation

A large Ka value indicates a strong acid because it means the acid is largely dissociated into its ions. A large Ka value also means the formation of products in the reaction is favored. A small Ka value means little of the acid dissociates, so you have a weak acid.

In addition, the smaller the pKa value, the stronger the acid.

Note: pKa = - log ka

To arrange the following according to increasing acid strength, first, convert the Ka to pKa using the formula above.

(i) Ka= 2.5 + 10⁻¹⁵

pKa = - (log 2.5 + log 10⁻¹⁵)

pKa = -(0.40 - 15)

pKa = -0.40 + 15 = 14.6

(ii) Ka= 9.0 + 10⁻⁹

pKa = - (log 9.0 + log 10⁻⁹)

pKa -(0.95 - 9)

pKa = -0.95 + 9 = 8.05

(iii) pKa = 7.5

(iv) % dissociation = 100

This implies the acid dissociates completely in water. Strong acids have a large dissociation constant, so they dissociate completely in water.

The smaller the pKa value, the stronger the acid.

Therefore the arrangement of the above according to increasing acid strength is:

(d) i, ii, iii, iv

Answer:

2. n= (.00201 L)(1.205 g *L-1)/29.0 g*mol-1      = 8.352 x10^-5 moles3. R=CP/n       =(.00001838)(1)/8.352 x10^-5       =0.22 L*atm/mol K4. R=0.08206 L*atm/mol KResults and discussion:What I learned from today’s lab is how volume and temperature relate to each other when taking the measurements and plotting them in a graph.

Definitely, possible error such as heat from our hands can transfer over to graduated cylinder which could change temperature of water.Questions:1. This experiment deals with the relationship between volume and temperature for a fixed amount of gas at constant pressure. Design an experiment, which would allow you to study the relationship between pressure and temperature for a fixed amount of gas at constant volume. Show a diagram of the apparatus and a plot of P versus T for the data you expect to obtain. Is the relationship between P and T direct or inverse?As the temperature increases the pressure also increases and vice versa.2. In this experiment, air was assumed to be an ideal gas. Does this assumption lead to a significant error? Explain your answer? This assumption would probably not lead to significant error unless the experiment is conducted through a change that would change the gas.3. Show by calculation that the weighted-average “molecular weight” of air is 29.0 g⋅ mol-1.

Explanation:

Answer:

Here's the PDF for mine, hope it helps you out.

According to the question the Ksp of KClO₃ at 74°C is 1.07 x 10-3 mol²/L²

Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. It is measured by a thermometer and indicated by a numerical value on a mutually agreed-upon temperature scale such as Celsius, Fahrenheit, or Kelvin.

The Ksp of a substance is the equilibrium constant for the dissolution reaction for that substance. To calculate the Ksp of KClO₃ at 74 oC, we first need to calculate the molar concentration of KClO₃ in the solution.
Since 4.00 g of KClO₃ has a molar mass of 122.5 g/mol, the molar concentration of KClO₃ would be
c = 4.00 g/122.5 g/mol = 0.0327 mol/L
The Ksp of KClO₃ at 74 oC can then be calculated using the following equation:
Ksp = [K+] x [ClO³⁻]
where [K+] and [ClO³⁻] are the molar concentrations of the K+ and ClO3- ions, respectively.
Since KClO₃ dissociates completely into K⁺ and ClO³⁻ ions, the molar concentration of each ion is equal to the molar concentration of KClO₃, which we calculated to be 0.0327 mol/L.
Therefore, the Ksp of KClO₃ at 74 oC is
Ksp = [K⁺] x [ClO³⁻] = (0.0327 mol/L) x (0.0327 mol/L) = 0.00107089 mol²/L²
or
Ksp = 1.07 x 10-3 mol²/L²

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Answer:

Hyponym is the another name for hard water.

Explanation:

Please Mark me brainliest

The final volume, when 0.607 L of a 47.0% (m/v) solution is diluted to 24.0% (m/v), is approximately 1185.417 mL.

To find the final volume when a solution is diluted, we can use the equation;

C₁V₁ = C₂V₂

where; C₁ is the initial concentration

V₁ is the initial volume

C₂ is the final concentration

V₂ is the final volume

Given;

Initial volume (V₁) = 0.607 L

Initial concentration (C₁) = 47.0% (m/v)

Final concentration (C₂) = 24.0% (m/v)

We need to calculate the final volume (V₂) in milliliters (mL).

Convert the initial and final concentrations to decimal form;

C₁ = 47.0% = 0.47 (m/v)

C₂ = 24.0% = 0.24 (m/v)

Convert the initial volume from liters to milliliters;

V₁ = 0.607 L × 1000 mL/L = 607 mL

Rearrange the equation and solve for V₂;

C₁V₁ = C₂V₂

V₂ = (C₁V₁) / C₂

V₂ = (0.47 × 607) / 0.24

V₂ ≈ 1185.417 mL

Therefore, the final volume is 1185.417 mL.

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If the reaction occurs with an 82. 4% yield mass of aluminum should be reacted with excess oxygen to produce 45. 0 grams of al2o3 is

4 Al(s) + 3 O2(g) → 2 Al2O3(s)

Molar mass of Al = 26.98 g/mol

Molar mass of O2 = 31.99 g/mol

Molar mass of Al2O3 = 101.96 g/mol

From the above-balanced reaction:

4 x 26.98 = 107.92 g of Al produces 2 x 101.96 = 203.92 g of Al2O3

Hence, the amount of 203.92 g of Al2O3 is 100% yield.

But given condition is only for 82.4% yield, so the mass of Al2O3 associated with an 82.4% yield

= 82.4 x 203.92 / 100

= 168.03 g of Al2O3

Now, as 168.03 g of Al2O3 requires 107.92 g of Al

So, Al required to produce 45.0 g of Al2O3 = 45.0 x 107.92 / 168.03

= 28.9 g of Al

Mass is the amount of matter in the physical body. It is also a measure of body inertia, resistance to acceleration when a net force is applied. An object's mass also determines the strength of gravity on other objects. The SI base unit of mass is the kilogram.

mass. A quantitative measure of inertia in physics, a fundamental property of all matter. In effect, it is the resistance that an object offers to changes in velocity or position when a force is applied. The greater the mass of an object, the smaller the change caused by an applied force. In mathematics, mass refers to the amount of matter in an object. Mass is commonly measured by the weight of an object. The more stuff you have, the heavier it will be. For example, mice have more matter than ants, so mice have more mass.

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If the reaction occurs with an 82. 4% yield, what mass of aluminum should be reacted with excess oxygen to produce 45. 0 grams of al2o3?

The most likely result of millions of metal atoms crowding together so that molecular orbitals become combined is the  formation of bands in a crystal and is therefore denoted as option B.

This is referred to as a three dimensional description of the most likely location of an electron around an atom.

In a scenario where millions of metal atoms crowding together so that molecular orbitals become combined the energy levels of their valence electrons are modified and a collection of large number of closely spaced energy levels are formed thereby resulting in the  formation of bands in a crystal.

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Answer:

B: the formation of bands in a crystaL

Explanation:

To get how many moles of NaCl you need, multiply the concentration (0.5 mols/Liters) by the desired volume of solution (0.5 Liters). To get the required number of grammes of solute, multiply the moles of NaCl by their molar mass (58.44 g/mol).

Three times as much SO2—six moles—are present in the balanced equation. As a result, we must multiply by three the moles of each reactant and product. Therefore, three times a mole of CS2 is added.

However, a formula is later provided, which reads: Gram atom = mass in grammes / Atomic mass [RAM]. There are other inquiries that make use of this formula ( similarly for gramme molecule).

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Answer:

its B

Explanation:

right on acellus

Answer:

b it seems like the only one that makes sense

the correct answer is b, I just took the quiz and the other answer on this question was correct

The absolute error that could be expected when measuring the half-life of radon-220 is 0.416 s

The following data were obtained from the question:

We can obtaine the absolute error as illustrated below:

Percentage error = (Absolute error / Actaul measurement) × 100

0.8% = Absolute error / 52

0.008 = Absolute error / 52

Cross multiply

Absolute error = 0.008 ×52

Absolute error = 0.416 s

Thus, the absolute error in measuring the half-life is 0.416 s

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Answer:

2x - 9y = 23

5x - 3y = -12x - 9y = 23

5x - 3y = -1

Explanation: