Write a description of how you know a chemical reaction is occurring.


ANSWER FAST FIRST PERSON GETS BRAINLIEST

Answer:

D

Explanation:

Sugar will dissolve faster when you stir the solution quickly because the act of stirring increases kinetic energy which increases the temperature.

\(\\ \sf\longmapsto Density=\dfrac{Mass}{Volume}\)

\(\\ \sf\longmapsto Density=\dfrac{400}{112}\)

\(\\ \sf\longmapsto Density=3.57g/mL\)

Answer:

2B2 + 3O2 → 2B2O3

Explanation:

Balance The Equation: B2 + O2 = B2O3

1. Label Each Compound With a Variable

  aB2 + bO2 = cB2O3

2. Create a System of Equations, One Per Element

  B: 2a + 0b = 2c

  O: 0a + 2b = 3c

3. Solve For All Variables (using substitution, gauss elimination, or a calculator)

  a = 2

  b = 3

  c = 2

4. Substitute Coefficients and Verify Result

  2B2 + 3O2 = 2B2O3

      L R

  B: 4 4 ✔️

  O: 6 6 ✔️

hope this helps!

This reaction is exothermic reaction and the q value is -484 kJ

An exothermic reaction is a chemical reaction that involves the release of energy in the form of heat or light

Here given reaction is

2H2(g) + O2(g) → 2H₂O(g)

In this reaction we can see that heat is released so if heat is released after completion of the reaction such reaction are called as exothermic reaction and thus given reaction is exothermic reaction

The fuel is hydrogen it react with oxygen from the air this is an exothermic reaction

So because of exothermic reaction ΔH = -ve

That why the q value is also negative so it is q = -484 kJ

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The correct answer is C) decrease agitation.

The rate of dissolution of a gas in a liquid is dependent on a number of factors including temperature, pressure, surface area, and agitation. When the agitation of the liquid is decreased, the rate of dissolution of the gas in the liquid also decreases. Agitation refers to the movement of the liquid and can be caused by stirring or shaking. When the liquid is agitated, it allows the gas molecules to come into contact with the liquid more frequently, which increases the rate of dissolution. Therefore, decreasing agitation will decrease the rate of dissolution of the gas in the liquid.

Increasing temperature, increasing surface area, and increasing pressure can all increase the rate of dissolution of a gas in a liquid. When the temperature is increased, the kinetic energy of the gas molecules increases, which allows them to move more freely and dissolve more quickly. Increasing surface area provides more contact between the gas and liquid, allowing for more rapid dissolution. Increasing pressure forces more gas molecules into the liquid, which increases the rate of dissolution.

Answer:

Mg donates two electrons to O

Explanation:

Lewis dot notation uses dots and crosses to represent valence electrons on atoms.

Magnesium is a metal and would donate or lose electrons during bonding.

Oxygen is a non metal and would gain electrons during bonding.

The correct option is;

Mg donates two electrons to O

Answer:

make an observation that describes a problem

Explanation:

Answer:

The first step in the Scientific Method is to make objective observations.

Explanation:

....-

The enthalpy of combustion for 1kg of urea is -1223525.84 J/mol.

Urea is a compound that is used in fertilizers and in some plastics.The enthalpy of combustion for urea is the amount of energy that is released when urea is burned. In order to calculate the enthalpy of combustion for 1kg of urea, we need to use the information that is provided to us in the question. Let us start by writing down the balanced equation for the combustion of urea: CO(NH2)2 + 3/2 O2 → CO2 + 2H2O + N2
The balanced equation shows that 1 mole of urea reacts with 1.5 moles of oxygen gas to produce 1 mole of carbon dioxide, 2 moles of water, and 1 mole of nitrogen gas. The enthalpy change for this reaction is equal to the amount of energy that is released when 1 mole of urea is burned.
The heat of combustion (ΔHc) of urea is -632.6 kJ/mol. This means that 632.6 kJ of energy is released when 1 mole of urea is burned. We know that 12g of urea raised the temperature of water by 30°C. We can use this information to calculate the amount of energy that was released when 12g of urea was burned.
The specific heat capacity of water is 4.18 J/g°C. This means that it takes 4.18 J of energy to raise the temperature of 1 gram of water by 1°C. Therefore, it takes 4.18 x 1000 = 4180 J of energy to raise the temperature of 1 kg of water by 1°C.
We know that 12g of urea raised the temperature of water by 30°C. Therefore, the amount of energy that was released when 12g of urea was burned is:
Energy = mass x specific heat capacity x temperature change
Energy = 0.012 kg x 4180 J/kg°C x 30°C
Energy = 1497.6 J
We can now use this information to calculate the enthalpy of combustion for 1kg of urea:
Enthalpy of combustion = energy released / moles of urea burned
Enthalpy of combustion = 1497.6 J / (0.012 kg / 60.06 g/mol)
Enthalpy of combustion = - 1223525.84 J/mol
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BaO has ionic bonds because of electronegative difference.

Ionic bonds, also known as electrovalent bonds, are a type of linkage created in a chemical compound by the electrostatic attraction of ions with opposing charges. When the valence (outermost) electrons of one atom are permanently transferred to another atom, a bond of this kind is created. If an atom gains electrons, it becomes a negatively charged ion (cation), while if it loses them, it becomes a positively charged ion (cation) (anion). Following is a brief discussion of ionic bonds. To learn more, go to chemical bonding: the ionic bonding process.

Ionic or electrovalent compounds are produced by ionic bonding, and the compounds formed between nonmetals and alkali and alkaline-earth metals serve as the best examples of this type of compound. Actually, a polar covalent bond is the extreme form of an ionic bond.

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The statement "All organic compounds contain the element carbon, but not all compounds containing the element 'carbon' are organic" can be justified based on the definition and characteristics of organic compounds.

Organic compounds are compounds primarily composed of carbon and hydrogen atoms, often with other elements like oxygen, nitrogen, sulfur, and phosphorus. These compounds are typically associated with living organisms and are known for their unique properties and behavior, including the ability to form complex structures, exhibit covalent bonding, and undergo organic reactions.

On the other hand, there are compounds that contain carbon but are not classified as organic. One notable example is carbon dioxide (\(CO_{2}\)), which is a simple inorganic compound composed of carbon and oxygen. Carbon dioxide does not possess the characteristic properties of organic compounds, such as the ability to form long chains or undergo organic reactions.

Additionally, there are inorganic compounds like carbonates (such as calcium carbonate) and carbides (such as calcium carbide) that contain carbon but are not considered organic. These compounds have distinct chemical and physical properties different from those of organic compounds.

In summary, while all organic compounds contain carbon, not all compounds containing carbon are organic. The classification of a compound as organic or inorganic depends on its overall molecular structure, bonding, and characteristic properties.

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Answer:

From these two values, i.e. mass and volume, density of the copper cylinder can be calculated.

Formula of density is :

Density = Mass / volume.

Now we have mass: 53.76g and volume 6cm³

Density = 53.76 / 6

Density= 8.96 g/cm³

Answer:

49.8 g C₆H₅Br

Explanation:

The theoretical yield is the maximum calculated amount of product that can be made from a reaction. To find the theoretical yield, you need to (1) determine the chemical reaction which is taking place, then (2) calculate the molar masses of the relevant reactants and product, then (3) convert grams of each reactant to grams of bromobenzene (using molar masses and mole-to-mole ratio from reaction coefficients), and then (4) determine the limiting reagent and the theoretical yield.

(Step 1)

Bromine = Br₂

Benzene = C₆H₆

Bromobenzene = C₆H₅Br

The balanced equation:

Br₂ + 2 C₆H₆ ----> 2 C₆H₅Br + H₂

(Step 2)

Molar Mass (Br₂): 2(79.904 g/mol)

Molar Mass (Br₂): 159.808 g/mol

Molar Mass (C₆H₆): 6(12.011 g/mol) + 6(1.008 g/mol)

Molar Mass (C₆H₆): 78.114 g/mol

Molar Mass (C₆H₅Br): 6(12.011 g/mol) + 5(1.008 g/mol) + 79.904 g/mol

Molar Mass (C₆H₅Br): 157.01 g/mol

(Step 3)

52.3 g Br₂           1 mole             2 moles C₆H₅Br         157.01 g
----------------- x  ------------------  x  -------------------------  x  ---------------  =
                          159.808 g              1 mole Br₂               1 mole

=  103 g C₆H₅Br

24.8 g C₆H₆         1 mole            2 moles C₆H₅Br          157.01 g
-------------------  x  ---------------  x  --------------------------  x  ---------------  =
                             78.114 g           2 moles C₆H₆             1 mole

=  49.8 g C₆H₅Br

(Step 4)

Because C₆H₆ produces a smaller amount of product than Br₂, it must be the limiting reagent. This means that it will run out before all of the Br₂ is used up. Therefore, the actual theoretical yield of C₆H₅Br is 49.8 grams.

Answer:

If a saturated hot solution is allowed to cool, the solute is no longer soluble in the solvent and forms crystals of pure compound. Impurities are excluded from the growing crystals and the pure solid crystals can be separated from the dissolved impurities by filtration.

The partial charges on each fluorine atom are negative. Option B) The central O atom is the correct answer. Option B

The partial charges in a molecule are determined by the electronegativity values of the atoms involved. Electronegativity is the ability of an atom to attract electrons towards itself in a chemical bond. In the case of \(F_2O\), fluorine (F) is more electronegative than oxygen.

Fluorine is the most electronegative element on the periodic table, meaning it has a high ability to attract electrons. Oxygen is also relatively electronegative but less so than fluorine. When fluorine atoms bond with oxygen, the shared electrons will be pulled more towards the fluorine atoms, creating a polar covalent bond.

In \(F_2O\), each fluorine atom will pull the shared electrons towards itself, resulting in a higher electron density around the fluorine atoms. This creates a region of partial negative charge around the fluorine atoms.

Conversely, the oxygen atom will have a region of lower electron density and, therefore, a partial positive charge. This is because the shared electrons spend more time around the fluorine atoms due to their higher electronegativity.

Option B

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Exothermic refers to chemical interactions that aerobic respiration. Combustion reactions release higher energy. Endothermic refers to atoms and molecules that either use or absorb reactive power.

A chemical process known as an endothermic releases energy as heat or light. It is an endothermic reaction's opposite. Chemical equation expressed as reactants + products + energy. An reaction mechanism is one in which electricity is given off as light or warmth.

A response is deemed to be exothermic if it produces heat while also undergoing a net decrease in basic enthalpy change. Samples include those type of combustion, iron rust, including water froze. Exothermic processes are those that discharge heat and energy into the surroundings.

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At pOH value  of 6.0 the pH value of the following solution is 8.0 and the concentration of [\(H^{+}\) ] ion is \(10^{-8}\)

In this question we will apply the formula

      pH +pOH = 14 . . . . . . . . . . . . .(1)

where pH = concentration of [\(H^{+}\) ] ion

pOH = concentration of [\(OH^{-}\) ] ion

As per the question

pOH =6.0

Putting the value of pOH in equation (1) we get the value of pH

              pH + 6.0 =14

             pH = 14 -6.0

             pH  = 8.0

 The value of pH if the pOH value is 6.0 is 8.0

To find the concentration of \(H^{+}\) ion we will use the following formula

This is calculated by the formula

                                 [\(H^{+}\)} = \(10^{-pH}\)

where we will write the values of pH

Hence the concentration of [\(H^{+}\)} ion is \(10^{-8}\)

Therefore at  pOH of 6.0 the pH value of the following solution is 8.0 and the concentration of [\(H^{+}\) ] ion is \(10^{-8}\)

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The complete question is -

What is the pH value and concentration of [\(H^{+}\) ] ion of the following if the pOH value of the solution is 6.0 ?

The percent error is 0.22%. This is a very small error, which suggests that our experimental result is quite accurate.

What is Boiling Point?

Boiling point is the temperature at which a liquid changes state from a liquid to a gas or vapor by the process of boiling. At the boiling point, the vapor pressure of the liquid equals the atmospheric pressure, causing bubbles of vapor to form within the liquid and rise to the surface. The boiling point is a physical property of a substance and can vary depending on the pressure and altitude.

A) To calculate the specific heat of the metal, we can use the equation:

q = m * c * ΔT

q_water = m_water * c_water * ΔT_water

= 98 g * 4.184 J/g°C * (28.2°C - 23.7°C)

= 1903.52 J

where c_water is the specific heat of water, which is 4.184 J/g°C.

Next, we need to calculate the heat released by the metal:

q_metal = -q_water

= -1903.52 J

where the negative sign indicates that the heat is released by the metal and absorbed by the water.

Now, we can calculate the specific heat of the metal:

c_metal = q_metal / (m_metal * ΔT_metal)

= -1903.52 J / (39.9 g * (100.3°C - 23.7°C))

= 0.450 J/g°C

Therefore, the specific heat of the metal is 0.450 J/g°C.

B) To identify the metal, we can compare its specific heat to the known values of specific heats for different metals. The specific heat of the metal we calculated is 0.450 J/g°C. Here are some common metals and their specific heats:

Aluminum: 0.900 J/g°C

Copper: 0.385 J/g°C

Iron: 0.449 J/g°C

Lead: 0.128 J/g°C

Silver: 0.235 J/g°C

Zinc: 0.388 J/g°C

From this, we can see that the specific heat of the metal we calculated is closest to that of iron, which suggests that the metal is likely to be iron.

C) To calculate the percent error, we need to compare the experimental specific heat we calculated (0.450 J/g°C) to the accepted value for iron's specific heat (0.449 J/g°C), using the formula:

percent error = |(0.450 J/g°C - 0.449 J/g°C) / 0.449 J/g°C| * 100%

= 0.22%

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Answer:

A. When two aqueous solutions are mixed, a precipitate is formed.

Explanation:

The precipitate (a solid substance that falls from the liquid) is the result of a chemical reaction taking place between the liquids.

The other three answer choices are indicative of physical changes (temperature change, phase change, color change).

When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.  

Hence, option A is correct answer.

Chemical change are those changes in which substance changes chemical composition. These changes are permanent changes. In chemical change new substances formed and in chemical change substances can not get back into its original form. It is irreversible change.

Physical changes are those changes in which substance changes physical properties only. Properties like temperature, pressure, shape, color, size, state (solid, liquid and gas). These changes are temporary in nature. In physical change no new substances formed. It is reversible change.

Now, check all the options one by one:

Option (A): When two aqueous solutions are mixed, a precipitate is formed is a chemical change. Since precipitation indicate a chemical reaction (that is double displacement reaction).

Option (B): As ammonium nitrate dissolved in water causes the temperature to decrease is a physical change because heat energy is absorbed here and it is a endothermic reaction.

Option (C): Alcohol evaporates when left in an open container is a physical change because evaporation is a physical change as it changes the state from liquid state to gas state.

Option (D): Water is added to blue copper (II) chloride solution. The resulting mixture if lighter blue in color is a physical change as properties like change in color is physical change.  

Thus, from above conclusion we can say that When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.  

Hence, option A is correct answer.

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The molarity of vinegar is 0.47368421 moles per liter.

To calculate this, we can use the following formula:

molarity = (initial_volume - total_volume_change) / final_volume

In this case, the initial volume is 7.5 mL, the total volume change is 21 mL, and the final volume is 28.5 mL. Plugging these values into the formula, we get:

molarity = (7.5 - 21) / 28.5 = -0.47368421

The negative value for molarity indicates that the solution is diluted. This is because the total volume of the solution increased by 21 mL, while the amount of solute (acetic acid) remained the same.

It is important to note that the molarity of a solution can change depending on the temperature. This is because the volume of a solution expands as it gets warmer. Therefore, it is important to measure the volume and temperature of a solution at the same time to get an accurate measurement of its molarity.

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This is a chemical produced by cells in the body, which circulates throughout the body in the bloodstream is Hormone. It affects a wide range of functions and acts on one or more target as tissues.

So, correct answer is Option A Hormone/Tissue

The chemical messengers of the body, hormones communicate with tissues and the bloodstream. Hormones affect a variety of bodily functions, including growth and development, metabolism—the process through which your body converts food into energy—sexual function, reproduction, and mood.

Tissue is colection of huge amount of cells. Connective tissue, epithelial tissue, muscular tissue, and nerve tissue are the four fundamental forms of tissue. Other tissues are held together and supported by connective tissue (bone, blood, and lymph tissues). A coating is provided by epithelial tissue (skin, the linings of the various passages inside the body).

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Entropy increase inIce Cubes Melting at -5 oC and 1 atm Pressure,The Reaction of Nitrogen Atoms to Form N2 Molecules at 25 oC and 1 atm,Formation of Liquid Water from Hydrogen and Oxygen Gases.

Entropy is a concept in thermodynamics that describes the amount of disorder or randomness in a system. It is typically a measure of randomness or uncertainty, and is represented by a number known as the entropy value. Entropy is related to the number of possible arrangements of energy in a system, and increases as the number of possible arrangements increases. For example, a completely ordered system has a low entropy, whereas a completely disordered system has a high entropy. Entropy also has an important role in the field of information theory, where it is used to measure the amount of information in a given system. In general, entropy measures the amount of disorder or randomness in a system, and is an important concept in thermodynamics, information theory, and other fields.

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Explanation:

Moles=mass/molar mass

moles × molar mass = mass

0.206 x 119= mass

Mass= 24. 51grams

Answer:

24.51 g to the nearest hundredth

Explanation:

1 mole of SOCl2 =  32 + 16 + 2 *35.5 = 119 g

0.206 mol = 0.206 * 119

=  24.51 g.

Answer: A

Explanation: You do the math to do the thingy

Answer: A  Because I asked My teacher

Explanation: Hope it helps

The correct option is B. CaBr2 + 2Na → 2NaBr + Ca because In option B, the reactants CaBr2 and Na are both metals with similar reactivities.

Exothermic reactions release energy and are defined as producing products with higher stability (lower energy) than the reactants. The exothermic reaction that happens during a fire and releases energy in the form of heat and light is the combustion reaction.

In terms of reactivity, the metals that are listed in the periodic table's lower left corner are the most active. Lithium, sodium, and potassium, for instance, all interact with water.

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Question:

Based on the reactivities of the elements involved, which reaction will form products that are more stable than the reactants?

A. 2AlBr3 + 3Zn → 3ZnBr2 + 2Al

B. CaBr2 + 2Na → 2NaBr + Ca

C. MgBr2 + H2 → 2HBr + Mg

D. BaBr2 + Ca → CaBr2 + Ba

E. 2LiBr + Ba → BaBr2 + 2Li

Answer:

The d-block and transition metal are not interchangeable terms because the d-block elements are a subset of the transition metal elements. The transition metals are defined as the elements that have partially filled d orbitals, which includes the d-block elements as well as other elements that have partially filled d orbitals in other blocks, such as lanthanides and actinides. Therefore, while all d-block elements are transition metals, not all transition metals are d-block elements.

Chromosome separation in bacteria starts just at DNA replication start site. Chromosomes that have been doubled before eukaryotes are divided condense.

Heating or electrical energy can be used to break down compounds. The energy disrupts the bonds that hold the atoms together and initiates a chemical reaction. The compound can split into two simple compounds or be broken into separate atoms when the bonds break down.

We must separate mixes for the reasons listed below: To remove the unnecessary components from a combination, various components of the mixture are separated. to take important components out of a combination in more than one place. to acquire pure materials.

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Answer:

That’s because of the law of conservation of energy, which states that: Energy cannot be created or destroyed.

Explanation:

Energy may change form during a chemical reaction. For example, energy may change from chemical energy to heat energy when gas burns in a furnace. The exact amount of energy remains after the reaction as before.

The mass percentage is an important method which is used to calculate the concentration of a solution. The amount of water needed to add in order to make 17.85 % NaCl solution is 230.1 g.

The mass percentage of a component in a solution is defined as the mass in grams of that component present per 100 g of the solution. The term mass percentage is denoted as w/w. It is used to calculate the concentration of a binary solution.

Mass percentage = Mass of the component in the solution / Total mass of solution × 100

17.85 = 50.0 / 50.0 + x × 100

0.1785 (50.0 + x) = 50.0

8.925 + 0.1785 x = 50.0

0.1785 x = 41.075

x = 230.1 g

Thus the amount of water added to make the solution is 230.1 g.

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