In an exothermic reaction, the water will _______ in a calorimeter. A. release heat B. drop in temperature C. drop in volume D. absorb heat

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

pKa=-log(Ka)

-log(1.4/10^-4) (the Ka of lactic acid)

pKa=3.85

pH=3.85+log (0.25/.75)

pH=3.37

HCl is an acid, so the 0.05M HCl is added to the acid and subtracted from the base

pH= 3.85+ log(0.24/0.76)

pH=3.35 after addition of HCl

Expected:

sp³ in all three molecules.

The hybridization of the central atom is related to the number of electron domains around that atom.

[tex]\begin{array}{c|c|c}\textbf{Number of Electron Domains} & \textbf{Hybridization}&\textbf{Example}\\ 2 & \text{sp} & \text{C as in CO}_2\\ 3 & \text{sp}^{2} & \text{C in H}_2\text{C}=\text{CH}_2\\ 4 &\text{sp}^{3} & \text{C as in CH}_4\end{array}[/tex].

What is an electron domain?

How many electron domains in BH₄⁻, CH₄, and NH₄⁺?

Answer: [tex]1.56\times 10^{-3}g[/tex]

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]

where,

Molarity = 250mM = [tex]250\times 10^{-3}M[/tex]

n= moles of solute  

[tex]V_s[/tex] = volume of solution in ml = 4L = 4000 ml

[tex]{\text {moles of solute}}=\frac{\text {given mass}}{\text {molar mass}}=\frac{xg}{40g/mol}=0.025x[/tex]

Now put all the given values in the formula of molarity, we get

[tex]250\times 10^{-3}=\frac{0.025\times x\times 1000}{4000ml}[/tex]

[tex]250\times 10^{-3}=\frac{0.025\times x\times 1000}{4000ml}[/tex]

[tex]x=1.56\times 10^{-3}g[/tex]

Therefore, the [tex]1.56\times 10^{-3}g[/tex] of NaOH must be dissolved.

The answer should be C. Technology is the application of the knowledge gained by science.

Answer:

C. Technology is the application of the knowledge gained by science.

Explanation:

Science is about the discovery of some novel compounds such as cancer curing drugs or understanding the kinetics of reaction mechanisms. Technology takes the discovery made by science and upscales the process and makes it more efficient. Technology involves stem cell engineering to create clones or making pesticide resistant plants.

ensure contant results

Answer:

2.0 × 10−3

Explanation:

this is the correct answer, i don't know why people gave the other answer 3/5 stars because that answer and work was correct.

The average rate of reaction for the first 580 seconds is 2.0 × 10−3 M/s.

The average rate is defined as the ratio of the change in concentration to the time taken. We are required here to find the average rate of the reaction over the first 580 seconds.

Hence, we have;

average rate = 1.8 M - 0.6 M/580 s - 0 s = 1.2 M/580 s  = 2.0 × 10−3 M/s

Hence, the average rate of reaction for the first 580 seconds is 2.0 × 10−3 M/s.

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certain types of rock, like granite, are very resistant to weathering. Igneous rocks tend to weather slowly because it is hard for water to penetrate them. Other types of rock, like limestone and marble are easily weathered because they dissolve easily in weak acids.

Answer:

1.50 L.

Explanation:

PV = nRT,

Where, P is the pressure if the gas,

V is the volume if the gas container,

n is the no. of gas moles,

R is the general gas constant,

T is the temperature of the gas.

n₁V₂ = n₂V₁.

V₁ = 1.0 L, V₂ = ??? L.

n₁ = mass/molar mass = (2.05 g)/(32.0 g/mol) = 0.064 mol.

n₂ = n₁ + (1.00 g)/(32.0 g/mol) = 0.0953 mol.

∴ V₂ = n₂V₁/n₁ = (0.0953 mol)(1.0 L)/(0.064 mol) = 1.489 L ≅ 1.50 L.

F > N > B > Be > Li. This ranking is based on the decreasing effective nuclear charge (Zeff) experienced by a valence electron in the listed elements.

The element lithium (Li) has the lowest effective nuclear charge. One valence electron is 2s orbital. The nucleus has three protons (atomic number 3), however the inner electrons in the[tex]1s^2[/tex] orbital shield the valence electron, reducing its effective charge.

The Beryllium (Be) follows. The 2s orbital has two valence electrons. Despite having a higher atomic number (4) than lithium, the presence of two inner electrons in the [tex]1s^2[/tex] orbital provides more shielding and a somewhat higher effective nuclear charge.

Boron (B): Three valence electrons in the [tex]2s^2 2p^1[/tex]configuration. Boron's nucleus has more protons (atomic number 5), making it more positive. Compared to beryllium, the [tex]2p^1[/tex] electron provides less shielding for the valence electron, but the [tex]1s^2[/tex] electrons still protect the [tex]2s^2[/tex] electrons.

Nitrogen has a higher effective nuclear charge than boron. One additional proton (atomic number 7) in its nucleus boosts its positive charge. The presence of three [tex]2p^2[/tex] electrons reduces the shielding effect on the valence electron, enhancing its nucleus attraction.

Fluorine (F) has the highest effective nuclear charge. Nine protons make its nucleus extremely positively charged. Seven [tex]2p^5[/tex] electrons reduce shielding and attract the valence electron to the nucleus, resulting in the highest effective nuclear charge. Therefore, F > N > B > Be > Li is the decreasing order.

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The effective nuclear charge (Zeff) typically increases from left to right across a period in the periodic table. Therefore, for the elements F, Li, Be, B, and N, the rank order by Zeff, from lowest to highest, would be: Li < Be < B < N < F.

The concept being asked here involves effective nuclear charge (Zeff), which highly depends on position in the periodic table. Generally, Zeff increases from left to right across a period. So, for a valence (outermost) electron in the elements you provided: F, Li, Be, B, and N, we would expect this trend to hold. The effective nuclear charge can be thought of as the net positive charge experienced by an electron in an atom. Inner electrons shield outer electrons from the full charge of the nucleus, leading to this effective reduction in charge.

Thus, using that knowledge, we can rank these elements as follows: Li < Be < B < N < F. This order means that Fluorine (F), being the furthest right on the periodic table, has the highest effective nuclear charge. The atomic nucleus of Fluorine exerts a stronger pull on its valence electron relative to the other elements that have been listed.

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Answer:

Ba(OH)₂(aq) + 2HCl(aq) → BaCl₂(aq) + 2H₂O(l).

Explanation:

1 mol of Barium Hydroxide with 2 moles of hydrochloric acid  to produce 1 mol of barium chloride and 2 moles of water according to the equation:

Ba(OH)₂(aq) + 2HCl(aq) → BaCl₂(aq) + 2H₂O(l).

The equation for the reaction of 1 mole of Barium Hydroxide with 2 moles of hydrochloric acid is Ba(OH)2 (aq) + 2HCl(aq) → BaCl2(aq) + 2H₂O(l), representing a neutralization reaction.

The question is asking for the equations for the reaction of 1 mol of Barium Hydroxide (Ba(OH)2) with 2 moles of hydrochloric acid (HCl). This is a type of chemical reaction called a neutralization reaction, where an acid and a base react to form water and a salt.

The balanced chemical equation for this reaction is: Ba(OH)2 (aq) + 2HCl(aq) → BaCl2(aq) + 2H₂O(l).

This indicates that one molecule of barium hydroxide reacts with two molecules of hydrochloric acid to produce one molecule of barium chloride and two molecules of water.

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Answer:

Trial 1 : n = 0.0002241 moles

Trail 2 :  n = 0.0002188 moles

Explanation:

Let's bring out the data in the question;

Pressure (P) = 1.2 atm

Number of moles (n) = ?

Both trials contain different values of Volume (V) and temperature (T)

The equation that relates all four parameters (V, T, P and n) is the ideal gas equation. It is given as;

PV = nRT where R = gas constant = 0.0821 L atm K−1 mol−1

Soving for n, we have;

n = PV / RT

Trial 1

Volume (V) = 4.2 ml = 0.0042 L (Converting to L by dividing by 1000)

Temperature (T) = 0.9 + 273 = 273.9K (Converting to Kelvin temperature)

n = (1.2 * 0.0042) / (0.0821 * 273.9)

n = 0.00504 / 22.48719

n = 0.0002241 moles

Trial 2

Volume (V) = 4.1 ml = 0.0041 L (Converting to L by dividing by 1000)

Temperature (T) = 0.9 + 273 = 273.9K (Converting to Kelvin temperature)

n = (1.2 * 0.0041) / (0.0821 * 273.9)

n = 0.00492 / 22.48719

n = 0.0002188 moles

When a solid (solute) comes in contact with the liquid (solvent), the solute goes about C) dissolution, in which the solid dissolves into the liquid.

~

As this is with regards to solute and solvent, the solid will eventually dissolve in the liquid. The answer is C. dissolution.

Answers:

1. D) 91.3 J

2. A) The metal with the higher specific heat capacity

3. B) 318 K

Step-by-step explanation:

1. E, q, w

ΔE = q + w

By convention, anything leaving the system is negative and anything entering the system is positive.

q = 0.0 J

w = -91.3 J

E = 0.0 - 91.3 = -91.3 J

2. Specific heat capacity

q = mCΔT

C = q/(mΔT)

If q and m are the same for each metal, then

ΔT ∝ 1/C = k/C  

As C increases, ΔT decreases.

Thus, the metal with the higher specific heat capacity will have the smaller temperature change.

3. Temperature on mixing

There are two heat flows in this problem.

Heat gained by cold water + heat lost by hot water = 0

                      q₁                    +                 q₂                 = 0

                 m₁CΔT₁                +             m₂CΔT₂           = 0

                 m₁ΔT₁                 x +              m₂ΔT₂           = 0

Data:

m₁ = 30.0 g

T₁ = 280. K

m₂ = 50.0 g

T₂ = 340 K

Calculations:

ΔT₁ = T_f - Ti = T_f - T₁ = (T_f - 280.) K  

ΔT₂ = T_f - Ti = T_f - T₂ = (T_f - 340) K  

30.0(T_f - 280.) + 50.0(T_f - 340)   = 0

30.0T_f - 8400 + 50.0T_f - 17 000 = 0

                           80.0T_f - 25 400 = 0

                                          80.0T_f = 25 400

                                                  T_f =25 400/80.0

                                                  T_f = 318 K

The final temperature of the mixture is 318 K.

Hi!

1. Assume that these percentages are the mass.

2. For each of Fe and O, divide the mass by the Ar (relative atomic mass).

Fe: 72.4/55.8 = 1.297 moles

O: 27.6/16 = 1.725 moles

3. Work out which mole value is smallest, then divide the bigger mole value by the smaller one.

1.297 is smaller than 1.725, so your empirical formula is 1.1297/1.1297 = 1 atom of iron, and 1.725/1.297 = 1.33 atoms of oxygen.

4. Ensure your atom values are whole numbers.

1.33 is not a whole number, so multiply both 1 and 1.33 by 3.

5. Write out your empirical formula.

Fe3O4

Hope that helps!

The empirical formula for magnetic iron oxide, given that it has 72.4% iron and 27.6% oxygen by mass, is Fe3O4.

The problem asks us to find the empirical formula for magnetic iron oxide. Given the percentage composition of iron and oxygen in the compound, we can look at it as if we had 100g of the substance. This would give us 72.4g of iron (Fe) and 27.6g of oxygen (O).

First, we convert these amounts to moles. The atomic mass of iron is approximately 55.845 g/mol and for oxygen is approximately 16.00 g/mol. Therefore, we have 1.3 mol Fe and 1.72 mol O.

To find the empirical formula, we divide each of these by the smallest number of moles to get a ratio. So, we have Fe1O1.3. However, an empirical formula should consist of whole numbers. Therefore, if we multiply both by the same factor, in this case, a factor of 3 will give us whole numbers, we get Fe3O4. Therefore, the empirical formula for magnetic iron oxide is Fe3O4.

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Answer:

a. Ca(s) + N₂(g) + 3O₂(g) → Ca(NO₃)₂(s).

b. C(s,graphite) + 2H₂(g) + 1/2O₂(g) → CH₃OH(l).

c. 3NaCl(s) + 4O₃(g) → 3NaClO₄(s).

Explanation:

a. The formation reaction of Ca(NO₃)₂(s) is:

Ca(s) + N₂(g) + 3O₂(g) → Ca(NO₃)₂(s).

b. The formation reaction of CH₃OH(l) is:

C(s,graphite) + 2H₂(g) + 1/2O₂(g) → CH₃OH(l).

c. The formation reaction of NaClO₄(s) is:

3NaCl(s) + 4O₃(g) → 3NaClO₄(s).

Formation reactions for Ca(NO3)2, CH3OH, and NaClO4 are demonstrated by combining the respective elements in their standard states to form the given compounds.

To write the formation reactions for the given substances, we need to express how they are formed from their most stable forms of the elements in their standard states. Here are the formation reactions:

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The correct answer is - intrusive rocks.

The intrusion is a process in which the rising magma in the Earth's crust, manages to break through pre-existing layers of rock, and after that cool off, solidify, and create new intrusive igneous rocks. By doing so, the magma is breaking up the layers of rocks, thus the intrusive igneous rocks that are forming from it, come to be inside totally different rock units. The intrusions are always happening inside the crust, and the rocks formed from them are igneous rocks that have large crystals because of the slow cooling off of the magma.

Answer:

Explanation:

The Kinetic Theory of gases states that the gases are made of small particles (atoms or molecules) which are in random motion.

Postulates of Kinetic Molecular Theory of gases:

1. All gases are made up of a large number of minute particles of molecules.

2. The molecules are separated from one another by large distances, called as intermolecular spaces.

3. The molecules are in the state of rapid motion in all directions. They collide with each other and the walls of the container, and thus change their directions.

4. There is no loss of energy when the molecules collide among themselves and the wall of the container.

5. The molecules are independent of each other as the molecules has no forces of interaction (repulsive or attractive) between molecules.

6. The pressure exerted by the gas is due to the collision of the molecules with the walls of the container per unit area.

7. The average Kinetic energy of the gas molecules is directly propotional to the absolute temperature.

Answer: vibrating molecules

Explanation:

a p e x

Answer:

Explanation:

As per the kinetic molecular theory, gases consist on a large number of tiny particles (atoms or molecules) in continuous rapid random motion.

The particles are so small that they are considered to have a negligible volume compared with the volume of the vessel where they are confined.

Since the number of molecules is so large, statistical approach can be applied.

The rapidly moving particles constantly collide among them and with the walls of the container. The collisions are considered elastic, which means that there is no loss of energy after the coliisions.

Applying classical (Newtonian) mechanic and the statistical approach, the kinetic theory calculates the pressure exerted by gases as the force exerted by the particles when they hit the walls of the container per unit of area.

The kinetic molecular theory explains that gases exert pressure through the constant random motion and collision of their molecules with each other and their container. The pressure is directly dependent on the number of collisions per unit time. At higher pressures, attraction between molecules slightly decreases the pressure.

The kinetic molecular theory provides a detailed explanation of how gases exert pressure. The theory asserts that gases are composed of a large number of widely separated, small molecules that are in constant random motion. These molecules are in continuous elastic collision with one another and the walls of their container.

Gas pressure is directly dependent on the number of gas molecules hitting a unit area of the container wall per unit of time. This can be visually conceptualized by imagining the molecules of a gas as numerous tiny balls bouncing off the container walls. Each collision exerts a small pressure on the wall, and the collective pressure of countless collisions creates the pressure we can measure.

According to Graham's law, these molecules move past each other easily and diffuse at relatively fast rates due to their small size and the large average distance between them. At higher pressures the force of attraction between molecules becomes significant pulling the molecules closer together and slightly decreasing the pressure or volume.

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Answer:

- 50.7 kJ.

Explanation:

Mn₃O₄(s) + CO(g) ⟶ 3MnO(s) + CO₂(g).

The first reaction be as it is:

Mn₃O₄(s) + 4CO(g) ⟶ 3Mn(s) + 4CO₂(g), ΔH₁ = 255.6 kJ.

The second reaction should be reversed and multiplied by 3 and also the value of its ΔH must multiplied by (- 3):

3Mn(s) + 3CO₂(g) ⟶ 3MnO(s) + 3CO(g), ΔH₂ = (- 3)(102.1 kJ) = - 306.3 kJ.

Mn₃O₄(s) + CO(g) ⟶ 3MnO(s) + CO₂(g).

∴ ΔH rxn = ΔH₁ + ΔH₂ = (255.6 kJ) + (- 306.3 kJ) = - 50.7 kJ.

Answer:

1. 65.1 kJ; 2. 558 g

Step-by-step explanation:

1.

M_r: 34.08

        2H₂S+ SO₂ ⟶ 3S + 2H₂O ; ΔH = -56.9 kJ

Treat the heat as if it were a product in the equation. Then use the molar ratio (56.9 kJ/2 mol H₂S) in the usual way.

Moles of H₂S = 78.0 g H₂S × (1 mol H₂S/34.08 g H₂S) = 2.289 mol H₂S

Amount of heat = 2.289 mol H₂S × (56.9 kJ/2 mol H₂S) = 65.1 kJ

The reaction releases 65.1 kJ of energy.

2.

M_r:   169.87

         2AgNO₃ + BaCl₂ ⟶ 2AgCl + Ba(NO₃)₂; ΔH = -345 kJ

Moles of AgNO₃ = 567 kJ × (2 mol AgNO₃/345 kJ = 3.287 mol AgNO₃

Mass of AgNO₃ = 3.287 mol AgNO₃ × (169.87 g AgNO₃/1 mol AgNO₃)

= 558 g AgNO₃

You need 558 g of AgNO₃.

The correct answer would be inductive reasoning.

Primavera?

Answer: inductive reasoning

Explanation:

We know that inductive reasoning starts with a series of observation and use it to frame a theory or a particular conclusion by inspecting the related topics.

Therefore, Answering questions by analyzing specific observations and using them to come to a more general understanding is known as inductive reasoning.

A. Metal

Metals are very conductive, malleable, and almost all of them are solid at room temperature.

Uranus. Its axis is tilted to almost 90 degrees.

Answer:

Uranus → rotates almost completely on its side

Explanation:

There are 8 planets in the solar system. Each has unique characteristics.  

Jupiter is the largest planet of the solar system. It has a giant red spot which is a huge storm in its atmosphere that is visible from Earth.

Saturn is famous for beautiful visible ring system.

Mars appears red dot wandering in the sky. It appears red because its surface contains red iron oxide.

Venus is the hottest planet because it has thick atmosphere which traps the sunlight.

Neptune and Uranus are blue in color because of the presence of methane in their atmosphere.

Uranus rotates on its side because its axis is tilted to about 98 degrees.

Answer:

[tex]m_{Mg}=30.8mgMg[/tex]

Explanation:

Hello,

Based on the given chemical reaction, as 31.2 mL of hydrogen are yielded, one computes its moles via the ideal gas equation under the stated conditions as shown below:

[tex]n_{H_2}=\frac{PV}{RT}=\frac{754torr*\frac{1atm}{760torr}*0.0312L}{0.082 \frac{atm*L}{mol*K}*298.15K}=1.27x10^{-3}molH_2[/tex]

Now, since the relationship between hydrogen and magnesium is 1 to 1, one computes its milligrams by following the shown below proportional factor development:

[tex]m_{Mg}=1.27x10^{-3}molH_2*\frac{1molMg}{1molH_2}*\frac{24.305gMg}{1molMg}*\frac{1000mgMg}{1gMg}\\m_{Mg}=30.8mgMg[/tex]

Best regards.

Is the atoms of electric

its definitely not photosynthesis!

its probably metamorphosis but i could be wrong

The cell is the smallest unit of an organism.  It is the first stage in the organization of life.

The cell is the smallest unit of an organism. The cell stands at the basic unit of life. It is the first stage in the organization of life.

The processes which occurs in the cells are;

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Answer:

There is negligible force of attraction between them.

Explanation:

According to kinetic molecular theory of gases:

a) They have high kinetic energy so the molecules show random motion.

b) The space between them increases with increase in temperature. With increase in temperature, the kinetic energy increases and the molecules move farther from each other, volume increases.

c) the average kinetic energy increases with increase in temperature

Thus only true statement is:

There is negligible force of attraction between them.

Based on the kinetic molecular theory, there is a negligible force of attraction between the particles in the sample of gas.

The correct statement is option B.

Kinetic molecular theory state that the particles of gas are large spherical and are in constant motion and have a perfectly elastic collision.

This theory can explain both Boyle's law and Charles's law.

Thus, the correct option is B, There is a negligible force of attraction between them.

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