3. Canxi oxit có thể tác dụng với chất nào sau đây ?

a. H2O, CO2, HCI, H2SO4

b. CO2, H2O, NaOH, HCI, c. H2O, CO2, HCI, Na2SO4

d. H2O, CO2, HCl, NaCl

Answer:

A, Heat is released as the reaction happens.

Explanation:

Exothermic reactions release heat and/or light and is a reaction in which the overall enthalpy is negative. The one your mouse is hovering over explains Nuclear Fission. The third one explains an endothermic reaction, as heat is absorbed in the reaction. The product being cold is actually one of the key characteristics of an endothermic reaction. Two liquids being mixed that forms a solid is called a precipitate.

Answer:

Lili green light green jacket gray jeans gray green jacket green green jacket jacket gray gray jeans jeans gray jacket gray gray

Answer:

^^^

Explanation:

The relative molecular mass of the compound is 45.8

The relative molecular mass of anisotope can be obtained by using the formula below:

Relative molecular mass = [(Mass of A × Abundance of A)/100] + [(Mass of B × Abundance of B)/100]

Where

The relative molecular mass can be obtained as illustrated below:

Relative molecular mass = [(Mass of A × Abundance of A)/100] + [(Mass of B × Abundance of B)/100]

Relative molecular mass = [(45 × 60)/100] + [(47× 40)/100]

Relative molecular mass = 27 + 18.8

Relative molecular mass = 45.8

Thus, the relative molecular mass is 45.8

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Answer: 63.6166 amu (atomic mass units)

Explanation: When an element X is written in the form of X-N, N will the atomic mass of that element. So we have copper with a mass of 63 and 65. We are given percentages of each one. 69.17/100 of the copper atoms will be of weight 63 while 30.83/100 will be of weight 65. Keep in mind that amu does not actually mean weight but I'm just using it as a tool to help explain the general concept. Assume you have 100 copper atoms, and you need to find the average atomic mass for them, if you do this you will solve the problem. Due to the fractions, 69.17 of them will be 63 amu and the rest will be 65. So do 69.17*63+65*30.83 and divide by one hundred. By doing this you will get 63.6166. If my answer doesn't make sense, search up how to calculate weighted averages

Hope this helps

Cobalt-60 is a radioisotope that decays by first order kinetics with a half life of 5. 26 years. When used in radiotherapy, a cobalt-60 unit is replaced when the concentration of co decreases to 75% of its initial value it occurs in 2.18 years.

Given that :

t1/2 = 5.26 years

k t1/2 = 0.693

k = 0.693 / 5.26

k = 0.132 yr^-1

ln ([A]t / [A]o) = - kt

[ Co ] = 0.75 [Co]

ln ( 0.75 [Co] / [Co]o) = - (0.132 yr^-1) t

ln 0.75 = - (0.132 yr^-1) t

-0.288 = - (0.132 yr^-1) t

t = - 0.288 / - (0.132 yr^-1)

t = 2.18 yr

Thus, Cobalt-60 is a radioisotope that decays by first order kinetics with a half life of 5. 26 years. When used in radiotherapy, a cobalt-60 unit is replaced when the concentration of co decreases to 75% of its initial value it occurs in 2.18 years.

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Proton:

Positive

Found in Nucleus

Mass of 1 AMU

Neutron:

Neutral

Found in Nucleus

Mass of 1 AMU

Electron:

Negative

Found in orbitals

Mass of 0 AMU

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In a voltaic cell, a salt bridge is needed to allow the motion of ions between the terminals. In the salt bridge, anions move toward the anode and cations move toward the cathode.

A voltaic cell is an electrochemical device that harnesses the power of a chemical process to generate electrical energy. A voltaic cell's key components are:

When an electrode is dipped into the electrolyte at the electrode and electrolyte contact surface in a voltaic cell, the electrode's atoms tend to produce positive ions in the electrolytic solution while leaving the electrode's electrons unaffected. The electrode thus acquires a negative charge.

Additionally, the electrolytic solution's positive ions have a propensity to deposit on the electrode, giving it a positive charge. The electrodes get positively or negatively charged in relation to the electrolyte as a result of the two opposite processes. As a result, there is a potential difference between the electrode and electrolyte. The term "electrode potential" refers to this potential difference.

Now, the electrode where reduction occurs is known as the cathode and turns positive in relation to the electrolytic solution, whereas the electrode where oxidation occurs is known as the anode and has a negative potential in relation to the electrolytic solution. This caused a potential difference to form between the voltaic cell's two electrodes. Cell Potential is the name given to this potential differential.

The voltaic cell's potential is sometimes referred to as its electromotive force (EMF) when no current is being drawn from it. Electrons begin to flow from the anode (negative electrode) to the cathode when an external circuit is connected to the voltaic cell (positive electrode). As a result, in the external circuit, the normal current flows from the positive terminal to the negative terminal.

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The pH of a 0.037 M solution of methylamine is 4.97.

The Kb value and the amount of methylamine present in the solution can be used to calculate the pH of a methylamine solution. As a weak base, methylamine interacts with water to produce the ions methylammonium (CH3NH3+) and hydroxide (OH) (OH-). The concentration of the hydroxide ion in solution can be determined using the equilibrium constant for this reaction, Kb:

Kb = [CH3NH3+] × [OH-] / [CH3NH2]

Since the concentration of methylamine is known, the concentration of the hydroxide ion can be calculated:

Kb = [OH-\(]^{2}\) / [CH3NH2]

[OH-] = sqrt(Kb × [CH3NH2]) = sqrt(4.38 x \(10^{-4}\) × 0.037) = 1.07 x \(10^{-5}\) M

The pH of the solution can be calculated using the concentration of the hydroxide ion:

pH = -log([OH-]) = -log(1.07 x \(10^{-5}\)) = 4.97

So, the pH of a 0.037 M solution of methylamine is 4.97.

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Styrofoam is a recommended material to use when constructing a calorimeter because it is a good insulator.

Styrofoam, also known as expanded polystyrene foam, is a popular material used for various applications, including insulation. It is a good insulator due to its low thermal conductivity.

The structure of Styrofoam consists of trapped air pockets within its foam cells, which hinders the transfer of heat energy. This property makes it effective at reducing heat exchange between the inside and outside environments.

In the context of a calorimeter, where heat measurements are taken, using Styrofoam helps minimize heat loss or gain from the surroundings, allowing for more accurate measurements of thermal changes.

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Answer:

the answer is B because it is a chemical reaction

Answer:

Potential Energy is stored energy or energy of position (gravitational). The object isn't moving. For example, a ball being held is potential energy because the object isn't moving but it has the potential of turning into kinetic energy.

Kinetic Energy is the energy of motion. For example, running. You are moving, and there is clear action and activity

Energy stored in an object due to its position is Potiential energy . Energy that is moving object has due to its motion is Kinetic energy .

Answer:

the correct answer is 0.37m

Explanation:

37/100 = 0.37m

Answer:

How many meters are in 37 cm?

In 37 cm - 0.37 m

>3

Answer:

14/6

Explanation:

U 2 can help me by marking as brainliest........

There can be emissions of radiations like gamma radiation. There can be emission of particles too like alpha particle. Therefore, the complete reaction is ¹⁴N₇ + ¹n₀ \(\rightarrow\) ¹⁴ C₆ + ¹H₁.

Nuclear decay is process in which the radioactive element releases particles or radiations. Alpha particles is ⁴₂He. Alpha particle is nothing but helium particle. There are so many types of nuclear decay. The kinetic for decay is of first order kinetics.

The balanced equation is the one in which the atomic number and mass number of element is always conserved. So, for the given decay, balanced reaction can be written as below

¹⁴N₇ + ¹n₀ \(\rightarrow\) ¹⁴ C₆ + ¹H₁

Generation of carbon takes place from nitrogen

Therefore, the complete reaction is ¹⁴N₇ + ¹n₀ \(\rightarrow\) ¹⁴ C₆ + ¹H₁.

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The gas law that defines the relation between volume and temperature is called Charles's law. The gas must be heated to 91 degrees celsius so that volume of 500 mL can be occupied.

"Charles's law is the ideal gas law that defines the relationship between the temperature and volume of the gas at the constant pressure." It describes how the gas expands and contracts at higher and lower temperatures.

The formula of Charles's law is given as:

V₁ ÷ T₁ = V₂ ÷ T₂

Given,

Initial temperature (T₁) = 0 degree celsius = 273 K

Initial volume (V₁) = 375 mL

Final temperature  = T₂

The final volume (V₂) = 500 mL

Substituting values in Charles's formulas as:

V₁ ÷ T₁ = V₂ ÷ T₂

T₂ = V₂T₂ ÷ V₁

T₂ = (500 mL × 273 K) / 375 mL

T₂ = 364 K

Converting K into degrees celsius as:

0 K − 273.15 = -273.1°C

364 K − 273.15 = 90.85 °C

Therefore, 91 °C is the final temperature of the gas.

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1.  the final concentration of NaOH after adding 125 mL of water to 45.3 mL of 0.71 M NaOH solution is approximately 0.189 M.

2.  the final concentration of KOH after adding 550 mL of water to 125 mL of 3.01 M KOH solution is approximately 0.557 M.

1.) If 125 mL of water is added to 45.3 mL of a 0.71 M NaOH solution, the resulting solution will be a diluted NaOH solution. The addition of water will increase the total volume while reducing the concentration of NaOH. To determine the final concentration of NaOH, we need to consider the conservation of moles.

First, let's calculate the moles of NaOH in the initial solution:

moles of NaOH = volume (in L) × concentration (in M)

moles of NaOH = 0.0453 L × 0.71 M = 0.0321433 moles

After adding 125 mL (0.125 L) of water, the total volume of the solution becomes 0.0453 L + 0.125 L = 0.1703 L.

To find the final concentration, we divide the moles of NaOH by the total volume:

final concentration of NaOH = moles of NaOH / total volume

final concentration of NaOH = 0.0321433 moles / 0.1703 L ≈ 0.189 M

Therefore, the final concentration of NaOH after adding 125 mL of water to 45.3 mL of 0.71 M NaOH solution is approximately 0.189 M.

2.) If 550 mL of water is added to 125 mL of a 3.01 M KOH solution, the resulting solution will also be a diluted solution. Again, we will apply the conservation of moles to determine the final concentration of KOH.

First, calculate the moles of KOH in the initial solution:

moles of KOH = volume (in L) × concentration (in M)

moles of KOH = 0.125 L × 3.01 M = 0.37625 moles

After adding 550 mL (0.55 L) of water, the total volume of the solution becomes 0.125 L + 0.55 L = 0.675 L.

To find the final concentration, divide the moles of KOH by the total volume:

final concentration of KOH = moles of KOH / total volume

final concentration of KOH = 0.37625 moles / 0.675 L ≈ 0.557 M

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The question provides us a list of chemical formulas with their respective names and requires us to show the "rough work" - show and calculate the charges of the elements in the molecule.

To calculate the charg

Answer:

29565 feet

Explanation:

multiply 5.6 by 5280

The values which describe standard temperature and pressure are 273.15  K and 101.3 kPa. Thus, the correct option is D.

Standard temperature and pressure is defined as a standard set of conditions  that are required for  measurements in experiments which are established  in order to allow comparison between different sets of data.

Standards which are commonly used are those International Union of pure and applied chemistry and national institute of standards and technology.They are not universally accepted standards but are the ones which are most commonly used.

The values which describe standard temperature and pressure are 273.15  K and 101.3 kPa respectively, thus option D is correct.

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The molality of concentrated aqueous HCl is 16.0 m and the mol fraction for the same solution is 0.0223.

[HCl]=12.0 M =12.0 mol HCl/1L solution

The density of solution = 1.19 g/ml

Thus, the mass of 1L of solution = Volume x density

=1000 ml x1.19 g/ml

=1190 g

Mass of HCl= Moles x Molar mass

=12.0 x36.5 g

=438 g

Thus, mass of water= mass of solution - mass of HCl

=1190- 438

=752 g

Molality is the ratio of number of moles to the weight of solvent in kg.

=12 mol x 1000 g/752 g x 1 kg

=16.0 m

Moles of water = mass/ molar mass

=752/18

=41.8 mol

Thus, the calculation of mole fraction is,

X_HCl=12.0/12.0+41.8

=0.223

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The main reservoirs of the carbon cycle are the atmosphere, oceans, land (including vegetation and soils), and fossil fuels. In these reservoirs, carbon exists in both inorganic and organic forms.

The inorganic carbon cycle involves the exchange of carbon dioxide (CO2) between the atmosphere and oceans through processes like photosynthesis and respiration.

Organic carbon, on the other hand, is found in living organisms, dead organic matter, and soil organic matter. It is cycled through processes such as decomposition and consumption by organisms. The interactions between the inorganic and organic carbon cycles occur primarily in the biosphere, where photosynthesis converts inorganic carbon into organic carbon compounds. While inorganic carbon is primarily in the form of CO2, organic carbon is present in complex organic molecules. Both forms of carbon play crucial roles in energy transfer, nutrient cycling, and climate regulation.

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Answer:

question 1 i believe is c i will put the other answeres in comments

when i finish the test

Explanation:

The carbon cycle plays an important in maintaining carbon balance on the earth.

The carbon cycle is the cycle by which carbon is recycled between the atmosphere and the geosphere.

In the carbon cycle, the process of recycling carbon do not include deep burial, compaction, and cementation.

Volcanic eruptions are one natural way that carbon can move OUT of the geosphere.

Fossil fuels, atmosphere, land biomass and rocks are all carbon reservoirs, but fossil fuels contains the MOST carbon.

The atmosphere is the carbon reservoir that changes the quickest and has the biggest direct effect on climate.

Ocean acidification occurs because the ocean absorbs more human-produced CO2, causing the acidity to increase.

A potential impact of ocean acidification is that ocean ecosystems may suffer, making it harder for humans to get food from the ocean.

Therefore, the carbon cycle is important in maintaining carbon balance on the earth.

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Gasohol is a blend of gasoline and ethanol. To determine the maximum work that can be obtained by burning 1.003 mol of C2H5OH at 25°C and 1 atm, the Gibbs free energy equation can be utilized. What is Gibbs free energy equation? Gibbs free energy equation is a thermodynamic equation that quantifies the maximum quantity of work that may be obtained during a chemical reaction. T

he equation is as follows: ΔG = ΔH - TΔSThe values of ΔH and ΔS are calculated from thermodynamic tables or by calculating the enthalpy and entropy of the products and reactants, and the temperature, T, is usually specified in Kelvin. The change in Gibbs free energy, ΔG, is the maximum amount of energy that can be obtained from the reaction in the form of useful work if the reaction takes place at constant pressure and temperature. The reaction will proceed spontaneously if ΔG is negative. And if ΔG is positive, the reaction will not take place spontaneously. The solution to this problem is shown below:

First, let's figure out how much heat is produced when one mole of C2H5OH is burnt.ΔHrxn = [2(moles of CO2)(-393.5 kJ/mol) + 3(moles of H2O)(-285.8 kJ/mol)] - [(moles of C2H5OH)(-277.7 kJ/mol)]ΔHrxn = [2(2.006 mol)(-393.5 kJ/mol) + 3(3.009 mol)(-285.8 kJ/mol)] - [1.003 mol(-277.7 kJ/mol)]ΔHrxn = -2043.5 kJ/mol. Now, we'll figure out the entropy change for the reaction.ΔSrxn = [2(moles of CO2)(213.8 J/mol-K) + 3(moles of H2O)(69.9 J/mol-K)] - [(moles of C2H5OH)(160.7 J/mol-K)]ΔSrxn = [2(2.006 mol)(213.8 J/mol-K) + 3(3.009 mol)(69.9 J/mol-K)] - [1.003 mol(160.7 J/mol-K)]ΔSrxn = -104.3 J/mol-KThe temperature in Kelvin is 25°C.273 + 25 = 298 KΔG = ΔH - TΔSΔG = -2043.5 kJ/mol - (298 K)(-104.3 J/mol-K)/1000ΔG = -2032.6 kJ/mol. Therefore, the maximum work that can be obtained by burning 1.003 mol of C2H5OH is 2032.6 kJ/mol, which is the value of ΔG.

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Answer: The concentration of given solution is 11.68 M.

Explanation:

Given: Mass of solute = 10 g

Volume of solution = 25 mL

Convert mL into L as follows.

\(1 mL = 0.001 L\\25 mL = 25 mL \times \frac{0.001}{1 mL}\\= 0.025 L\)

Number of moles is the mass of substance divided by its molar mass. The moles of sugar (molar mass = 342.3 g/mol) is as follows.

\(No. of moles = \frac{mass}{molar mass}\\= \frac{10 g}{342.3 g/mol}\\= 0.0292 mol\)

Molarity is the number of moles of solute present in a liter of solution.

Hence, concentration of given solution is calculated as follows.

\(Molarity = \frac{no. of moles}{Volume (in L)}\\= \frac{0.0292 mol}{0.025 L}\\= 11.68 M\)

Thus, we can conclude that the concentration of given solution is 11.68 M.

After the axolemma has depolarized during an action potential, it quickly repolarizes via voltage-gated potassium channels. Potassium leak channels, sodium leak channels, and Na+/K+ ATPase are also important components of the resting membrane potential of a neuron, but they do not play a direct role in the repolarization of an action potential.

The axolemma is a specialized membrane that surrounds axons, the long projections of neurons that carry electrical signals. When an action potential is triggered, the axolemma depolarizes, meaning that the membrane potential becomes less negative due to an influx of positively charged ions. To return to its resting state, the axolemma must repolarize, which involves the efflux of positively charged ions, particularly potassium ions.

Voltage-gated potassium channels are specialized ion channels that open in response to a change in membrane potential. During an action potential, the depolarization of the axolemma opens voltage-gated sodium channels, allowing sodium ions to flow into the cell and further depolarize the membrane. As the membrane potential continues to become more positive, voltage-gated potassium channels open as well, allowing potassium ions to flow out of the cell and repolarize the membrane.

This rapid efflux of potassium ions is responsible for the sharp decline in membrane potential that characterizes the falling phase of an action potential.

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Sucrose has the molecular  C₁₂H₂₂O₁₁ . if a sucrose sample contains 9.0x10²⁴ atoms of hydrogen, There are 1.4370 x10²⁶ molecules of sucrose are present in the sample.

Sucrose C₁₂H₂₂O₁₁ contain  C₁₂H₂₂O₁₁  Hydrogen

First we should how how many percentage of hydrogen in sucrose

The following formula will be used to determine the percentage of elements present in a molecule:

(Mass of Element / Mass of Molecule) / 100 equals the percentage of an element.

Sucrose's molecular weight is.

= (12)12 + (1)22 + (16)11, 

where 12 is the mass of an atom of carbon.

Hydrogen's atomic mass is 1, thus.

16 = Oxygen Atomic Mass

mass sucrose = 144 + 22 + 176

mass sucrose = 342 g/mol

% of H  =  (22 / 342) ×100    =  6.43 %

to calculate how many molecules sucrose are present we can compare percentage of hydrogen to % sucrose

 % hydrogen         =         % sucrose            

atom hydrogen           molecules of sucrose

6.43 %        =              100%              

9.0x10²⁴          molecules of sucrose    

molecules of sucrose    = 1.4370 x10²⁶ molecules

Therefore,  There are 1.4370 x10²⁶ molecules of sucrose are present in the sample.

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Answer:

The answer to this question is C; ultraviolet radiation

Explanation:

The the reason for this is because it carries more energy per photon than visible light does. Light travels at a speed of 299,792 kilometers per second (about 186,282 miles per second).