Given the equation `x² + 2x + y² + 4y = 20`, complete the square to rewrite it and identify the centers and radius of the circle. The answer to the question is
Completing the square:
[x^2 + 2x + y^2 + 4y = 20\]\[x^2 + 2x + 1 - 1 + y^2 + 4y + 4 - 4 = 20\]\[(x + 1)^2 + (y + 2)^2 = 25\]
This equation is in the standard form of a circle, that is:
[(x - h)^2 + (y - k)^2 = r^2\]
where `(h, k)` is the center of the circle and `r` is its radius.
The equation of the given circle is \[(x + 1)^2 + (y + 2)^2 = 5^2\].
Therefore, the center of the circle is `(-1, -2)` and its radius is `5`.
We are given the equation x² + 2x + y² + 4y = 20 and we need to complete the square to rewrite the equation and identify the center and radius of the circle. We know that the standard form of a circle is (x - h)² + (y - k)² = r².
To transform the equation into the standard form of the circle, we need to complete the square. We can complete the square by adding and subtracting (1 + 4) on the left-hand side of the equation, which is equal to adding and subtracting 5 (5 is half of the coefficient of y) on the right-hand side of the equation.
This gives us:(x² + 2x + 1) - 1 + (y² + 4y + 4) - 4 = 20 + 5 - 5(x + 1)² + (y + 2)² = 25
This simplifies to:(x + 1)² + (y + 2)² = 5², which is in the standard form of a circle.
Therefore, the center of the circle is (-1, -2) and its radius is 5.
In conclusion, we have found that the equation of the given circle is (x + 1)² + (y + 2)² = 5². We have also found that the center of the circle is (-1, -2) an;
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Determine the pH of the resulting solution when the following two solutions are mixed: 20.0 mL of 0.20 M HC2H2O2 and 20.0 mL of 0.10 M NaOH. The value of Ka for HC2H2O2 is 1.8 x 10-5.
The pH of the resulting solution when 20.0 mL of 0.20 M HC₂H₂O₂and 20.0 mL of 0.10 M NaOH are mixed is 3.07.
Neutralization is a chemical reaction in which acid and base react to form salt and water. Hydrogen (H⁺) ions and hydroxide (OH⁻ ions) react with each other to form water.
The strong acid and strong base neutralization have a pH value of 7.
The balanced equation for the reaction is:
HC₂H₂O₂ + NaOH → NaC₂H₃O₂ + H₂O
Moles of HC₂H₂O₂= concentration × volume = 0.20 M × 0.020 L = 0.004 mol
Moles of NaOH = concentration × volume = 0.10 M × 0.020 L = 0.002 mol
Since HC₂H₂O₂ is a weak acid, it will partially dissociate in water according to the equation:
HC₂H₂O₂ ⇌ H⁺ + C₂H₂O₂⁻
Initial:
HC₂H₂O₂: 0.004 M
H⁺: 0 M
C₂H₂O₂⁻: 0 M
Change:
HC₂H₂O₂: -x M
H⁺: +x M
C₂H₂O₂⁻: +x M
Equilibrium:
HC₂H₂O₂: 0.004 - x M
H⁺: x M
C₂H₂O₂⁻: x M
Ka = [H⁺][ C₂H₂O₂⁻] / [HC₂H₂O₂]
1.8 x 10⁻⁵ = x × x / (0.004 - x)
Since x is small compared to 0.004, so 0.004 - x = 0.004:
1.8 x 10⁻⁵= x² / 0.004
x² = 1.8 x 10⁻⁵ × 0.004
x² = 7.2 x 10⁻⁸
x = 8.49 x 10⁻⁴ M = [H⁺]
pH = -log( 8.49 x 10⁻⁴)
pH = 3.07
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which of the following elements would you expect to form diatomic molecules?
a. sulphur
b. argon
c. helium
d. hydrogen
The element that is expected to form diatomic molecules is d. hydrogen (H).
Diatomic molecules are molecules composed of two atoms of the same element bonded together. They are stable configurations for certain elements under normal conditions. Hydrogen is a diatomic element, meaning it naturally exists as H, with two hydrogen atoms bonded together.
On the other hand, the other options do not typically form diatomic molecules under normal conditions.
- Sulphur (S) is an element that exists as S8, forming octatomic molecules made up of eight sulphur atoms bonded together.
- Argon (Ar) is a noble gas and exists as single atoms. Noble gases are generally non-reactive and do not form diatomic molecules.
- Helium (He) is also a noble gas and exists as single atoms. Like other noble gases, helium does not readily form diatomic molecules.
Therefore, among the given options, hydrogen (H) is the element that is expected to form diatomic molecules.
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how many h+ ions can the acid h3po4 donate per molecule?
The acid H3PO4 can donate three hydrogen ions (H+) per molecule.
Thus, the number of H+ ions that the acid H3PO4 can donate per molecule is 3.Explanation:H3PO4 is also known as phosphoric acid. Phosphoric acid is an inorganic mineral acid that is commonly used in fertilizers, detergents, and food additives.
The chemical formula of H3PO4 is H3PO4 which implies that it has three hydrogen ions that are attached to the phosphate anion.Each hydrogen ion, which is donated by H3PO4, has the ability to donate a single positive hydrogen ion or proton (H+).
Therefore, since H3PO4 has three hydrogen ions, it has the ability to donate three H+ ions per molecule (per H3PO4 molecule).
In other words, one molecule of H3PO4 can donate three hydrogen ions.
Therefore, the number of H+ ions that the acid H3PO4 can donate per molecule is 3.
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what instrument is used to measure the average kinetic energy in a substance?
A thermometer is an instrument used to measure the average kinetic energy in a substance.
The average kinetic energy of particles in a substance is directly related to its temperature. The higher the temperature, the greater the average kinetic energy of the particles, and vice versa. Thermometers are designed to measure this average kinetic energy and provide a numerical value known as temperature.
Most thermometers operate based on the principle of thermal expansion. They use a temperature-sensitive material, such as mercury or alcohol, enclosed in a narrow, sealed tube. As the temperature changes, the substance inside the tube expands or contracts, causing the level of the substance to rise or fall.
A common example is a mercury-in-glass thermometer. It consists of a glass tube with a small bulb at the bottom filled with mercury. As the temperature increases, the thermal energy causes the mercury to expand, and it rises the tube.
So, a thermometer is used to measure the average kinetic energy in a substance by detecting and quantifying its temperature.
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A C4 plant is so named because oxaloacetate has _____ carbons.
C4 plants are named so because they utilize a four-carbon molecule, oxaloacetate, as their first carbon molecule. C4 plants are special types of plants that have evolved to use a highly efficient carbon fixation pathway in order to maintain their photosynthetic rates in hot, arid environments where water is scarce.
C4 plants have specific adaptations that enable them to thrive in such environments. For example, they have thick waxy leaves to reduce water loss, and they use PEP carboxylase to fix CO2 into a four-carbon molecule that is then transported to bundle sheath cells for further processing in a specialized process.
Additionally, C4 plants have a unique arrangement of photosynthetic cells that minimizes photorespiration and allows them to maintain high photosynthetic rates at higher temperatures and under drought conditions. These plants are commonly found in hot, dry climates and are typically grasses, but include some crops such as corn, sugar cane, and sorghum.
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What is the common name of the following compound? CH3CH2OCH3
The common name of the following compound CH₃CH₂OCH₃ is ethyl methyl ether.
Ethyl methyl ether, commonly known as ethyl methyl ether, is a colorless, flammable gas with a mild odor. It is an ether composed of two carbon atoms in a row (ethane), an oxygen atom connected to one of them, and a methyl (CH₃) group linked to the other.
The chemical formula for ethyl methyl ether is CH₃CH₂OCH₃. The IUPAC name for ethyl methyl ether is ethoxyethane, but it is more often referred to by its common name. It is used in a variety of industrial and laboratory applications, such as as a solvent for cellulose, resins, and oils, as well as a refrigerant and a local anesthetic.
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what is the role of oxygen in energy yielding pathways
Oxygen plays a crucial role in energy-yielding pathways by serving as the final electron acceptor in the electron transport chain (ETC) during cellular respiration.
Oxygen is the most important factor in energy-yielding pathways. The oxygen molecule is the final acceptor of electrons in cellular respiration, which is the process of energy production in cells. When electrons are passed down the electron transport chain, they lose energy, which is then used to pump hydrogen ions (protons) out of the mitochondrial matrix. This creates a concentration gradient of hydrogen ions, which then flow back into the matrix through ATP synthase.
The flow of hydrogen ions back into the matrix releases energy that is used to produce ATP from ADP and inorganic phosphate. Oxygen, as the final electron acceptor, is essential for this process because it helps to maintain the electron transport chain by accepting the electrons at the end of the process and allowing the cycle to continue. In summary, oxygen's role in energy-yielding pathways is crucial for the production of ATP, the main source of energy for cellular processes.
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