What type of reactions require energy in order to start?

Answer:

Explanation:

1. geologists using a seismograph to record vibrations moving through the Earth.

2. chemists using a computer program to analyze data from their experiments.

3. physicists using a water tank to observe the way waves interact with a model rehi.

Those three clearly describe the role of technology in science because all those researchers are using those technological equipment's for their scientific research to get an outcome (Result).

Chemists analyzing data, physicists observing wave behavior, and geologists recording seismic activity are all examples of technology being used in science.

The statements that are examples of technology in science include:

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The product X belongs to ester class of organic compounds.

Catalyst is a substance or material that speeds up a chemical reaction.

The chemical formula of ester group is RCOOR¹. Esters are formed when the alcohol and carboxylic acid reacts. Here butanoic acid is carboxylic acid and 1-pentanol is alcohol group.

The given equation is:

Butanoic Acid + 1-Pentanol [tex]\overset{H^+}\rightarrow[/tex] X + water

CH₃-CH₂-CH₂-COOH + CH₃-CH₂-CH₂-CH₂-CH₂OH  [tex]\overset{H^+}\rightarrow[/tex] CH₃-CH₂-CH₂-COO  CH₂-CH₂-CH₂-CH₂-CH₃ + water

Here X belongs to ester group.

Thus, from above conclusion we can say that the product X belongs to ester class of organic compounds.

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Answer:

(OH-)=1x10^-12 M

Explanation:

Both pH and pOH have a relationship to belonging to the same aqueous solution: the expression of the Kwater (ionic product of the water Kw) is used:

(H3O+) x (OH-) = 1x10^-14

(0,010) x (OH-)= 1x10^-14

(OH-)=1x10^-14/(0,010)

(OH-)=1x10^-12 M

Answer:

Aluminum Chloride

Explanation:

Answer:

5.6

Explanation:

since HCl is a strong acid we know that it completely dissasociates into H+ and Cl-

We can just treat the HCl as the H+ concentration and take the -log

-log(2.5E-6) = 5.6

Answer:

7.625g/cm³

Explanation:

Density = mass/volume

Volume of the block=2cm×2cm×4cm=16cm³

Mass of the block=122g

Density=122/16

=7.625

Therefore, the density of the block is 7.625g/cm³

Final answer:

To raise the temperature of a 55.0 g sample of water by 65.0°C, 14943 joules of heat energy is required, calculated using the specific heat capacity of water and the formula for heat energy.

Explanation:

The student asks about the quantity of heat energy needed to raise the temperature of a given sample of water. To calculate this, we will use the formula Q = m × c × ΔT, where 'Q' is the heat energy in joules (J), 'm' is the mass of the water in grams (g), 'c' is the specific heat capacity (4.18 J/g°C for water), and 'ΔT' is the change in temperature (°C).

In this scenario, the mass of water is 55.0 g, and we want to heat it by 65.0 °C. Therefore, we calculate the heat energy required as follows:

Q = 55.0 g × 4.18 J/g°C × 65.0 °C

Q = 55.0 × 4.18 × 65.0

Q = 14943 J

So, 14943 joules of heat energy is required to raise the temperature of a 55.0 g sample of water by 65.0°C.

Answer:

8.03L

Explanation:

Given parameters:

Initial volume, V₁  = 8.7L

Initial temperature T₁  = 50°C , in Kelvin gives 50+273  = 323K

Final temperature T₂ = 25°C, in Kelvin gives 25 + 273  = 298K

Unknown:

Final volume V₂  = ?

Solution:

Since we are dealing with volume and temperature relationships under constant pressure, we simply apply the Charles's law.

Charles's law states that "the volume of a given mass of gas is directly proportional to the temperature provided the pressure remains constant".

Mathematically, we have;

              [tex]\frac{V_{1} }{T_{1} } = \frac{V_{2} }{T_{2} }[/tex]

where V andV T are volume and temperature, 1 and 2 are initial and final states.

Input the parameters and solve for V₂;

            [tex]\frac{8.7}{323} = \frac{V_{2} }{298}[/tex]

          V₂  = 8.03L

Answer:

B

Explanation:

Answer:

β the answer is β

Explanation:

Final answer:

To make a 1.35 L solution, 0.189 mol of sodium hydroxide (NaOH) is required.

Explanation:

To find the number of moles of sodium hydroxide (NaOH) required to make a 1.35 L solution, we first need to determine the concentration of the solution in mol · dm-3. Given that 3.5 g of NaOH is dissolved in 2.5 dm3 of water, we can calculate the concentration using the formula:

Concentration (mol · dm-3) = moles of solute / volume of solution (dm3)

Concentration = (3.5 g / 39.997 g/mol) / 2.5 dm3 = 0.14 mol · dm-3

Now, to find the number of moles of NaOH required for a 1.35 L solution, we can use the formula:

Moles of solute = concentration · volume (L)

Moles of NaOH = 0.14 mol · dm-3 × 1.35 L = 0.189 mol

The shift often happens when heat is applied or removed at a specific temperature, also referred to as the substance's melting or boiling point. The temperature at which a substance transforms from a solid into a liquid is known as the melting point.

The physical concept of temperature indicates in numerical form how hot or cold something is. A thermometer is used to determine temperature. Thermometers are calibrated using a variety of temperature scales, which historically defined distinct reference points and thermometric substances.

When a substance immediately transitions from the solid to gas state, it is said to sublimate. Deposition is the opposite of sublimation, occurring when a substance changes from a gaseous state to a solid state.

For instance, you have undoubtedly seen the simple processes of forming ice, melting ice, and boiling water to cause freezing, melting, and vaporization. Cold beverage containers frequently develop condensation on their exteriors. When this happens, the liquid on the container's surface is created straight from the humid air.

Thus, The temperature at which a substance transforms from a solid into a liquid is known as the melting point.

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The dissociation reaction of weak acid is

[tex]HA_{aq} +H_{2}O_{l} \rightleftharpoons H_{3}O^{+} +A^{-} _{aq}[/tex]

For strong acid dissociation reaction is given by

[tex]HA_{aq} +H_{2} O_{l}\rightarrow H_{3}O^{+}+A^{-} _{aq}[/tex]

Dissociation is a reaction in which acid release its hydronium ion in water. Dissociation of acid depends on the kind of solvent that are there with acids.

Strong acid dissociates at is fullest, means all the hydronium ions releases from acid so it is irreversible reaction, rate of dissociation of acid is very high. Hydrochloric acid is example of strong acid.

Whereas in case of weak acid, It does not dissociate at its fullest level, its dissociation is poor. The rate of dessociation of acid is very low. Acetic acid is an example of weak acid. Dissociationin weak acid is a reversible process.

Thus dessociation of weak acid is poor while in case of strong acid it is very high.

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A weak acid partially dissociates in water, for example, CH₃COOH forms CH₃COO⁻ and H⁺. A strong acid fully dissociates, like HCl into H⁺ and Cl⁻. HCl is a stronger acid than HF, and in a neutralization reaction, H⁺ reacts with OH⁻ to form water.

Chemical reactions involving acids can be represented by their ionization in water. A weak acid like acetic acid  (CH₃COOH ) partially dissociates in water to form CH3COO⁻ and H⁺ ions:

CH₃COOH(aq) + H₂O(l) ↔ CH₃COO⁻(aq) + H⁺(aq)

A strong acid such as hydrochloric acid (HCl) fully dissociates in water to give H⁺ and Cl⁻ ions:

HCl(aq) → H⁺(aq) + Cl⁻(aq)

Answering the specific question on which of the two acids HCl(aq) or HF(aq) is stronger: HCl(aq) is the stronger acid since it completely dissociates in solution, whereas HF(aq) partially dissociates, making it a weak acid.

For the neutralization of a strong acid with a base, the net ionic equation generally represents the reaction between hydrogen ions and hydroxide ions to form water. An example of such a reaction is:

H⁺(aq) + OH⁻(aq) → H₂O(l)

Answer:

See explanation below

Explanation:

To answer this better, let's write the overall equation:

Mg(s) + Fe²⁺(aq) -----------> Mg²⁺(aq) + Fe(s)

Now the question shows us options of which equation is the half reaction that describes reduction. To do this, we need to know what is happening here, and what a reduction means here.

A reduction in a reaction takes place when an atom or compound gains electrons. This can be easily identified in this reaction because when an atom has a higher positive number, means that it's losing electron, and if it has a lower positive number and even negative numbers, means that is gaining the electrons.

In other words, if you have a number line, and put the 0 in the center, any movement that goes from 1 position to the right of the line, means that it's losing electrons (oxidizing) and if it goes to the left, it's gaining electrons (Reduction).

With this explained, let's write the half reactions taking place:

Mg(s) -----------> Mg²⁺

Fe²⁺ -----------> Fe(s)

When an atom it's in solid state, the oxidation number of the atom it's always zero, therefore, in the case of Mg, it goes from 0 to 2+, and Fe goes from 2+ to 0. According to the explanation above, if we go to the left we are reducting and if we go to the right, we are oxidizing. Therefore, as Fe goes from 2+ to 0, this means that is gaining 2 electrons, and it's reducting while Mg, it's oxidizing and losing electrons.

The half reactions then:

Mg(s) -----------> Mg²⁺ + 2e⁻    (Oxidizing)

Fe²⁺ + 2e⁻-----------> Fe(s)       (Reducting)

In this case, it would be the option 1.

Answer:

It's A

Explanation:

Answer : The oxygen will appears in the final chemical equation as a reactant.

Explanation :

The given chemical reactions are:

(1) [tex]C(s)+\frac{1}{2}O_2(g)\rightarrow CO(g)[/tex]

(2) [tex]CO(g)+\frac{1}{2}O_2(g)\rightarrow CO_2(g)[/tex]

Now we are adding reaction 1 and reaction 2, we get the final chemical equation.

The final chemical equation is:

[tex]C(s)+O_2(g)\rightarrow CO_2(g)[/tex]

Thus, the oxygen will appears in the final chemical equation as a reactant.

Answer:

The oxygen will appears in the final chemical equation as a reactant.

Explanation:

got a 100% on the unit test

Answer:

NaNO3

NaCI

(NH4)2SO4

NH4Cl

Explanation:

Odyssey ware

Answer:

Explanation:

The law of multiple proportions states that, when two elements can react with each other to form two or more different compounds, the weights of one element that react with a fixed weight of the other are in a ratio of small whole numbers.

1. If the mass of product obtained were 22.0g

Then, the mass of the oxygen atoms in the product would be:

The ratio of the weight of oxygen to the weight of carbon is 16.0 g to  6.0 g,

2. If the mass of product obtained were 14.0g.

3. Conclusion

Take a fixed amount of carbon equal to 3 grams.

Then, the amount of oxygen for the first compound would be 8 grams and the amount of oxygen for the second compound would be 4 grams.

That means that the ratio is 8 : 4 = 2.

Which is saying that, for the two compounds of carbon and oxygen, the weights of oxygen that reacts with a fixed weight of carbon are in a ratio of small whole numbers, in accordance to the law of multiple proportions.

Answer:

Gold.

Explanation:

The specific heat is the measure to determine which material needs a lesser amount of energy to rise its temperature. Specific heats are described below:

Aluminium: [tex]903\,\frac{J}{kg\cdot ^{\circ}C}[/tex]

Gold : [tex]129\,\frac{J}{kg\cdot ^{\circ}C}[/tex]

Water: [tex]4184\,\frac{J}{kg\cdot ^{\circ}C}[/tex]

Wood: [tex]1300\,\frac{J}{kg\cdot ^{\circ}C}[/tex]

Gold reports the lowest specific heat and, hence, requires the least energy to raise its temperature 7°C.

Answer: Trade winds are caused by the strong warming and evaporation within the atmosphere around the equator. (1) Around the equator, the warm air rises rapidly, carrying a lot of moisture.

Answer:

The Coriolis Effect.

Explanation:

combination with an area of high pressure, causes the prevailing winds—the trade winds—to move from east to west on both sides of the equator across this 60-degree "belt.

Answer: The algae lives on the crabs and this provides the crabs with a camouflage and gives the algae a place to live so this is beneficiary to both. In other words Spider crabs and Algae are Mutualism to eachothe.

Explanation:

Answer:

Arachnid?\

Explanation:

Hey there!

Your answer is no.

The difference between isotopes is the number of neutrons, not the number of protons.

For example, we have carbon-12 and carbon-14, two different isotopes of carbon. One has 6 protons and 6 neutrons, while one has 6 protons and 8 neutrons. They have the same amount of protons.

If you change the number of protons, then you have a different element. Isotopes are the same element.

Hope this helps!

Answer:

The temperature would be 304, 87 K

Explanation:

We use the formula PV= nRT:

T= PV/nR = 1,00 atm x 100L /4,00 mol x 0,082 l atm/K mol=304, 87 K

The temperature would be 304, 87 K

Answer:

Li⁺

Explanation:

Li⁺ ions has a noble gas electron configuration because it resembles that of He.

To have a noble configuration, electrons in the outermost shell must completely fill their respective orbitals.

Li⁺ is an ion that has lost one electron from the usual number of 3 thereby remaining 2 electrons.

 The electronic configuration is given as;

         Li⁺       1s²

The S orbital can hold a maximum number of just two electrons.

     Helium atom has two electrons with electronic configuration of  1s²

Therefore      Li⁺   =    1s²    =    He

The Li+ ion has a noble gas electron configuration, which mirrors the electron configuration of helium (He) by having two electrons in the 1s subshell after losing one valence electron.

The Li+ ion has a noble gas electron configuration. Lithium (Li) has an atomic number of 3, which corresponds to three electrons in a neutral atom. These three electrons are arranged in the 1s subshell (two electrons) and the 2s subshell (one electron), giving lithium an electron configuration of 1s²2s¹. When lithium loses its one valence electron, it forms a Li+ cation with a configuration of 1s², which mirrors the electron configuration of the noble gas helium (He). Since lithium is an alkali metal in Group 1A of the periodic table, it tends to form a 1+ charge when it becomes an ion, which is indicated by the noble gas electron configuration it achieves as Li+.

Answer:

nonmetal atoms that share electrons

Answer:

The new volumen of the solution is 500 ml.

Explanation:

A dilution consists of the decrease of concentration of a substance in a solution (the higher the volume of the solvent, the lower the concentration).

We use the formula for dilutions:

C1 x V1 = C2 x V2

V2= (C1xV1)/C2

V2= (400 ml x 2,5 M)/2,0M

V2= 500 ml

Answer:

1m

Explanation:

Answer:

a gradual increase in the overall temperature of the earth's atmosphere generally attributed to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants.

Explanation:

Answer:

the wavelength, in nm, of the photon is 487.5 nm

Explanation:

Given:

n = 4 (excited)

n = 2 (relaxes)

Question: Calculate the wavelength, in nm, λ = ?

First, it is important to calculate the energy of the electron when it excited and then when it relaxes.

[tex]E_{1} =\frac{-13.6}{n^{2} } =\frac{-13.6}{4^{2} } =-0.85eV[/tex] (excited)

[tex]E_{2} =\frac{-13.6}{2^{2} } =-3.4eV[/tex] (relaxes)

The change of energy

ΔE = E₁ - E₂=-0.85 - (-3.4) = 2.55 eV = 4.08x10⁻¹⁹J

For a photon, the wavelength emitted

[tex]\lambda =\frac{hc}{delta(E)}[/tex]

Here

h = Planck's constant = 6.63x10⁻³⁴J s

c = speed of light = 3x10⁸m/s

Substituting values:

[tex]\lambda =\frac{6.63x10^{-34}*3x10^{8} }{4.08x10^{-19} } =4.875x10^{-7} m=487.5nm[/tex]

Answer: 287.8 cm3

Explanation:

Given that:

Initial volume of gas V1 = 350 cm3

Initial pressure of gas P1 = 740 mmHg

New volume V2 = ?

New pressure P2 = 900 mmHg

Since, pressure and volume are involved while temperature is constant, apply the formula for Boyle's law

P1V1 = P2V2

740 mmHg x 350 cm3 = 900mmHg x V2

V2 = (740 mmHg x 350 cm3) /900mmHg

V2 = 259000 mmHg cm3 / 900mmHg

V2 = 287.8 cm3

Thus, the gas will occupy 287.8 cubic centimeters at the new pressure.

Answer:

D

Explanation:

Answer:

A Alpha

Explanation:

Answer: 1. Chloroplast

2. Light

3. Oxygen

Explanation: answer on edge

Answer:

How does photosynthesis occur?

The reactants collect in the  

✔ { chloroplast . }

✔{ Light  } energy from the sun drives chemical reactions.

The products include glucose and  ✔ { oxygen }, which is released into the air.

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