The correct label for the salts is:
a) NaCN = acidic, NH4F = basic, KCN = neutral
- NaCN: Sodium cyanide (NaCN) is a salt of a weak acid (HCN) and a strong base (NaOH). The weak acid (HCN) partially dissociates in water, producing cyanide ions (CN-) and a small amount of H+ ions, making the solution slightly acidic.
- NH4F: Ammonium fluoride (NH4F) is a salt of a weak base (NH3) and a strong acid (HF). The weak base (NH3) partially reacts with water to produce ammonium ions (NH4+) and hydroxide ions (OH-), making the solution slightly basic.
- KCN: Potassium cyanide (KCN) is a salt of a weak acid (HCN) and a strong base (KOH). Similar to NaCN, KCN produces cyanide ions (CN-) and a small amount of H+ ions in water, resulting in a neutral solution.
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The recipe for Bananas Foster requires 35g of ethanol to be added to the pan. The ethanol starts at room temperature (25°C) and is heated to its boiling point of 78°C. How many Joules of energy are transferred from the stove burner to the ethanol to create this temperature change? Your answer should have the correct number of significant figures. Show all work.
Given: The specific heat of ethanol is 2.46 J/g°C.
Answer:
To calculate the amount of heat released we have equation, use the equation Q = mc ΔT,
where
m= 35g
c= 2.46 J/g°C
ΔT=T2-T1 = 78-25= 53°C
now Q = mcΔT
Q = 35×2.46×53
Q = 4563.3 joule
Conclusion 4563.3 Joules of energy are transferred from the stove burner to the ethanol to create this temperature change!
How many molecules are there in 24 grams of HSO₃?
how can we find out the mass of the marble
In a collection of marbles, 25% of the marbles have a mass of 5.00 g and 75% of the marbles have a mass of 7.00 g. The average mass of a marble is 6.50 g.
Answer it right for a brainliest
Answer:
plz I. need a brainliest
Explanation:
I hope you have a good day
the energy transformation that occurs when a firework goes off is a chemical to thermal to light and sound. however, some of the energy is destroyed during the explosion
Answer:
false
Explanation:
energy can't be destroyed
If you initially have a gas with a pressure of 0.950 atm and a temperature of 35 °C and you heat it to 65 °C, what is the new pressure if volume and moles are held constant? (P2 = 1.04 atm)
Explanation:
fgIf the piston moves so as to increase the pressure of the gas to 2.94 atm, ... new volume of the cylinder? ... A gas has a pressure of 699.0 mm Hg at 40.0°C. What is the temperature (in C) ...
Madison is heating two different liquids. For each liquid, she wants to compare the temperatures at which gas bubbles form, rise, and begin to escape. What physical property is Madison using to compare the liquids?Immersive Reader boiling point conductivity melting point solubility
Answer:
I think its boiling point conductivity
Answer: boiling point
Explanation:
Got it right
How many moles are 2.20 x 10^25 atoms of zinc?
Please answer quick will give Brainliest!
Answer:
1.3244 x 10⁴⁹ atoms of zinc
Explanation:
2.20 x 10²⁵ moles
To convert from moles to atoms, we multiply by Avogadro's Number, 6.02 x 10²³
2.20 x 10²⁵ • 6.02 x 10²³
= 1.3244 x 10⁴⁹ atoms of zinc
Hope this helps!
9. Which of the following would increase the
validity of Experiment 2?
A. Testing magnets with a volume less
than 0.04
B. Testing magnets made of iron instead
of ceramic
C. Testing generators with larger
vibrations
D. Testing a generator with coils fewer
than 2050
.
When the molecules in a gas lose energy the gas will turn into a liquid.
A. True
B. False
Answer:
true
Explanation:
Answer:
true
Explanation:
when the temperature of the gas is decreased or pressure on the gas is increased, the gas becomes liquid at a certain temperature or pressure.
write the chemical equation for the reaction of monohydrogen phosphate ion, hpo42− , with water.
The chemical equation for the reaction of the monohydrogen phosphate ion (HPO₄²⁻) with water (H₂O) is: HPO₄²⁻ + H₂O → H₂PO₄⁻ + OH⁻
In this reaction, the monohydrogen phosphate ion reacts with water to form dihydrogen phosphate (H₂PO₄⁻) and hydroxide ion (OH⁻). The monohydrogen phosphate ion donates a proton (H⁺) to a water molecule, resulting in the formation of the dihydrogen phosphate ion.
Simultaneously, the water molecule accepts the proton, leading to the production of the hydroxide ion. This reaction can occur because the monohydrogen phosphate ion is amphoteric, meaning it can act as both an acid and a base.
The resulting products, dihydrogen phosphate and hydroxide ions, contribute to the pH and ionic balance in aqueous solutions.
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if the isentropic efficiency of the turbine is 80%, calculate the actual work output of the turbine, in kj/kg.
The required actual work output of the turbine is 1.2 Mj/kg.
If the isentropic efficiency of the turbine is 80%, calculate the actual work output of the turbine, in kj/kg.A steam turbine receives steam at a particular pressure and temperature and discharges it at a lower pressure and temperature. In general, the steam turbine's work output is less than the maximum possible work output, which is known as the isentropic turbine work output. The ratio of the actual turbine work output to the isentropic turbine work output is known as the isentropic turbine efficiency.ηt = Wtisentropic/WtactualWhere,ηt = isentropic turbine efficiencyWtisentropic = isentropic turbine work outputWtactual = actual turbine work outputGiven, isentropic efficiency of the turbine is 80%.ηt = 80% or ηt = 0.8We know thatWtactual = ηt x Wtisentropicor Wtisentropic = Wtactual/ ηtWe also know thath1 = 3.6 Mj/kgh2 = 2.1 Mj/kghence,Δh = h1 - h2 = 3.6 - 2.1 = 1.5 Mj/kgNow we have, Wtisentropic = Δh = 1.5 Mj/kgWtactual = ηt x Wtisentropic = 0.8 x 1.5= 1.2 Mj/kgTherefore, the actual work output of the turbine is 1.2 Mj/kg.
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a) Water has a molar mass of 18 g/mol and a density of 1000 kg/m3 (or 1 g/cm3). Based on this data, estimate the number of water molecules per unit surface area of water.
b) The coordination number of water (i.e., the average number of "neighbors" each water molecule has) in the liquid state is 4. Neighboring water molecules attract each other via hydrogen bonds, each of which has a binding energy of roughly 10–20 J (although this number depends relatively strongly on temperature). Use this information to estimate the surface tension of water. How does your estimate compare to the observed figure (
γ water = 0.072 N/m ) (hints: Keep in mind that we can think of
surface tension as surface energy per unit area, and consider the energy needed to bring a molecule from the bulk to the surface)?
The estimate is still useful because it provides insight into the behavior of water molecules at the surface of the liquid.
Molar mass of water, M = 18g/molDensity of water, ρ = 1g/cm³ = 1000kg/m³The number of molecules per unit surface area of water can be estimated as follows:Number of water molecules per unit volume of water = Avogadro's number, NA / MNumber of water molecules per unit volume of water = 6.022 × 10²³ / 18 = 3.345 × 10²² / molThe number of molecules per unit surface area of water = the number of molecules per unit volume of water × the thickness of the water layer on the surface= 3.345 × 10²² / m³ × 1 × 10⁻⁸ m= 3.345 × 10¹⁴ / m²b)Given:Coordination number of water, CN = 4Binding energy of hydrogen bond, E = 10⁻²⁰ JThe surface tension of water, γ water = 0.072 N/mEnergy required to bring one molecule from the bulk of the liquid to the surface of the liquid, ΔE= γ water × AThe total binding energy of a water molecule in the liquid state = the binding energy of one hydrogen bond × the coordination number= 10⁻²⁰ J/bond × 4 bonds = 4 × 10⁻²⁰ JThe number of molecules per unit surface area of water = the energy required to bring one molecule from the bulk of the liquid to the surface of the liquid / the total binding energy of a water molecule in the liquid state= ΔE / 4 × 10⁻²⁰= 0.072 / (4 × 10⁻²⁰)= 1.8 × 10²⁰The surface tension of water can also be expressed as follows:γ water = (N / A) × EThe number of hydrogen bonds per unit area, N / A = γ water / E= 0.072 / 10⁻²⁰ = 7.2 × 10¹⁸ / m²The difference between the estimated value and the observed value is relatively large (about a factor of 25). It is because this is just an estimate, and it does not consider all the factors affecting the surface tension of water. However, the estimate is still useful because it provides insight into the behavior of water molecules at the surface of the liquid.
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describe the relationship between the mole information of a substance and its chemical formula
The mole information of a substance is directly related to its chemical formula. The coefficients in a balanced chemical equation represent the mole ratios between the reactants and products.
The chemical formula of a substance provides information about the types and numbers of atoms present in a molecule or formula unit. It serves as a concise representation of the composition of the substance.
For example, consider the balanced equation for the combustion of methane with oxygen:
[tex]CH_4 + 2O_2[/tex] →[tex]CO_2 + 2H_2O[/tex]
From this equation, we can determine that one mole of methane reacts with two moles of oxygen to produce one mole of carbon dioxide and two moles of water. The coefficients (1, 2, 1, and 2) indicate the mole ratios between the reactants and products.
The mole information provided by the chemical formula and the coefficients in a balanced chemical equation allow us to determine the stoichiometry of a reaction, including the number of moles of each substance involved. This relationship between the mole information and the chemical formula is essential for performing stoichiometric calculations and understanding the quantitative aspects of chemical reactions.
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determine the molar mass of water. WRITE THE UNITS
H,(8) + 1,65) - HI(g) (H = 26 kJ/mol.. Hg) + 44 1,(g) HI(g) AH=-5.0 kJ/mol... Based on the information above, what is the enthalpy change for the sublimation of iodine, represented below? 1 (s) 1,08) A. 15 kJ/mol... B 21 kJ/mol. C. 31 kJ/mol.D. 42 kJ/mol, E. 62 kJ/mol.
The enthalpy change for the sublimation of iodine I₂(s) → I₂(g) is 62 kJ/mol.
The correct answer is E: 62 kJ/mol
What is the enthalpy change for the sublimation of iodine?The enthalpy change for the sublimation of iodine (I₂) is determined using Hess's Law which states that the total enthalpy change of a reaction is independent of the pathway taken.
Given the two equations:
½ H₂(g) + ½ I₂(s) → HI(g) ΔH = 26 kJ/mol ---- (1)
½ H₂(g) + ½ I₂(g) → HI(g) ΔH = -5.0 kJ/mol ---- (2)
The equation of the sublimation of iodine is given below as follows:
I₂(s) → I₂(g)
Subtracting equation 2 from equation 1 to eliminate HI (g) gives the equation of the sublimation of iodine:
[½ H₂(g) + ½ I₂(s) → HI(g)] - [½ H₂(g) + ½ I₂(g) → HI(g)] = 26 kJ/mol - (-5.0 kJ/mol)
Simplifying:
½ I₂(s) → ½ I₂(g) ΔH = 31 kJ/mol
Multiplying the equation above by 2 gives the equation of the sublimation of iodine
I₂(s) → I₂(g) = 62 kJ/mol
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How many molecules are in
6.0 moles of methane (CH4)?
Let's begin by setting up our equation.
What belongs in the green box?
6.0 moles CHA
A. 1 mole CH4
B. 6.02 x 1023 molecules CH4
Which of the following does not cause water pollution?
A
Domestic Waste
B
Insecticides and Herbicides
C
Heavy Metals
D
Dissolved Oxygen
Dissolved Oxygen (option D) does not cause water pollution. It is an essential component of water quality and supports aquatic life.
Water pollution refers to the contamination of water bodies, such as rivers, lakes, and oceans, by harmful substances. While all the options listed are associated with water quality, the one that does not cause water pollution is Dissolved Oxygen (option D).
Dissolved Oxygen refers to the presence of oxygen molecules dissolved in water. It is crucial for the survival of aquatic organisms, as they rely on it for respiration. Adequate levels of dissolved oxygen support healthy ecosystems and biodiversity in aquatic environments.
On the other hand, the remaining options, namely Domestic Waste (option A), Insecticides and Herbicides (option B), and Heavy Metals (option C), can contribute to water pollution. Domestic waste may contain organic matter, pathogens, and chemicals that can contaminate water sources. Insecticides and herbicides are chemical substances used to control pests and weeds, and their runoff into water bodies can harm aquatic organisms. Heavy metals, such as mercury, lead, and cadmium, can accumulate in water and have toxic effects on aquatic life.
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Why are different detergents made for cleaning different surfaces and how their chemical structure/composition affects this?
Answer: This is because of the different chemical composition of the types of detergents affects their cleansing actions.
Explanation:
Detergent means any substance which has the ability to clean an object. This includes soaps, soap powers and dish washing liquids as well as water. Detergents fall into two main types
--> Soapy detergents and
--> Soapless detergents
Soapy detergents are sodium salts of fatty acids. They are saponification products of fats and oils. In the chemical composition, each molecule of soap possesses a long hydrocarbon chain attached to an ionic head. The hydrocarbon tail is hydrophobic, so it is insoluble in water but soluble in oil and organic solvents. The ionic head is hydrophilic, so it is soluble in water. Due to this dual nature, when is dissolved in water, the soap molecule forms spherical clusters called MICELLES( hydrocarbon tails points inward and ionic heads point outward). Repulsion between the similarly charged ionic heads keeps the micelles apart. This property helps the soapy detergent to lift grease from grease coated fabrics when applied to it.
While the chemical properties of the Soapless detergents has a hydrophobic tail and a hydrophilic head. The hydrophobic tail is either a long chain hydrocarbon or a benzene ring with a long alkyl group attached. The hydrophilic head, unlike the Soapy detergents, can be positively or negatively charged or even neutral. These chemical properties makes it to have a more favourable and wider application than soapy detergent.it is suitable for washing acid - sensitive fabrics and for breaking up oil slicks.
Which one of the following systems has the highest entropy?
10 mL of water at 100°C
10 mL of water at 50°C
10 mL of water at 10°C
Answer: a
Explanation:
The highest entropy will be 0 mL of water at 100°C.
What is entropy?Entropy is just a measured physical quality that will be most usually linked with disorder, unpredictability, or uncertainty.
The quantity of random movement in a system increases as more energy is put into it. Entropy rises like a volume increases in a system.
Therefore, the correct answer will be option 1.
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How would potential energy and kinetic energy change going down stairs one at a time or two at a time?(1 point)
A) Going down stairs two at a time means you will get down in fewer steps, which saves you some kinetic and potential energy.
B) If you go down stairs two at a time, then you are going a greater distance, which will decrease your potential energy. Your kinetic energy will be less when you land on the stair.
C) Going down stairs two at a time will give you twice as much kinetic energy by the time you reach the bottom stair.
D)If you go down stairs two at a time, then your potential energy relative to the stair is greater. Your kinetic energy will be greater when you land.
When going down stairs, choosing to go two steps at a time will result in changes to both potential and kinetic energy. Option B is the correct statement as going down two steps at a time increases the distance traveled, leading to a decrease in potential energy, while the landing impact reduces the kinetic energy.
Option B accurately describes the changes in potential and kinetic energy when going down stairs two steps at a time. As you descend two steps at a time, you cover a greater vertical distance compared to going one step at a time. This increase in distance decreases your potential energy since potential energy is directly related to height. With each step, you experience a decrease in potential energy as you get closer to the ground.
However, when you land on the stair after going down two steps, your kinetic energy is reduced. This is because landing involves a sudden stop and impact, which leads to a dissipation of energy. The energy that was initially in the form of kinetic energy gets transferred to other forms, such as sound or heat. As a result, your overall kinetic energy is reduced compared to going down one step at a time, where each landing impact is less forceful.
Therefore, while the potential energy decreases due to the increased distance traveled, the kinetic energy decreases due to the landing impact when going down stairs two steps at a time.
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Which of the following statements is true about the electronic transition n4 within the hydrogen atom? of n2 A photon within the visible range will be emitted A photon within the infrared range will be emitted A photon within the ultraviolet range will be emitted No photon will be emitted
The electronic transition n=4 to n=2 within the hydrogen atom corresponds to the emission of a photon within the visible range.
The electronic transitions in hydrogen atoms involve the movement of an electron from one energy level (n) to another. The energy of the emitted photon is given by the difference in energy between the initial and final energy levels.
In this case, the transition n=4 to n=2 corresponds to an electron moving from the fourth energy level to the second energy level. This transition results in the emission of a photon. The energy of the emitted photon is equal to the energy difference between these two levels.
The energy of a photon is directly related to its wavelength. Photons with higher energy have shorter wavelengths, and photons with lower energy have longer wavelengths. The visible range of light is characterized by photons with wavelengths between approximately 400 to 700 nanometers.
Since the n=4 to n=2 transition corresponds to the emission of a photon, and the visible range falls within this energy range, the correct statement is that a photon within the visible range will be emitted during this electronic transition.
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In addition to showing the ratio of atoms in a molecule, what else do the subscripts in a formula tell us?
Answer:
See explanation
Explanation:
Usually, when we write a chemical formula for any compound or other chemical specie, we use subscripts to;
Indicate the ratio of atoms of each element present in the compound or chemical specieShow the number of atoms of each element present in the compound or chemical specie.Hence, the subscripts written after chemical formulas have more than one function as described above.
In H2SO4 for instance, there are two hydrogen atoms, one sulphur atom and four oxygen atoms as shown in the chemical formula.
How is meiosis different from mitosis
Answer:
A - meiosis results in two genetically identical offspring cell
Explanation:
Mitosis produces two diploid (2n) somatic cells that are genetically identical to each other and the original parent cell, whereas meiosis produces four haploid (n) gametes that are genetically unique from each other and the original parent (germ) cell.
Answer:
The answer is C
Explanation:
I took the test on AP3X
the form of energy that your lunch represents is?
A) electrical
B) chemical
C) thermal
D) nuclear
Balance the equation :
CoBr3 + CaSO4
please define how many atoms each element contain
Answer:
im not 2100][dskcmaln,NMCS KHJBXsjk[pl,;maxkcjxnxxxxxxxxxxxxxas'j
Explanation:
mnkc
When CuCl2 reacts with NaNO3, copper (II) nitrate and sodium chloride are formed.
a) Write the balanced equation for the reaction given above:
CuCl2 + NaNO3 à Cu(NO3)2 + NaCl
Answer:
CuCl2 + 2NaNO3 -------> Cu(NO3)2 + 2NaCl
hope this helps
good day mate
In the following reaction, the partial
pressure at equilibrium for each of the
products, CO and water vapor at 990°
C, is 11.0 atm and the partial pressure
for each of the reactants, H2 and CO2,
at equilibrium is 8.70 atm. What is Kp?
H2(g) + CO2(g) + H2O(g) + CO(g)
Kp = [?]
Answer:
H2+CO2=H2O+CO
Kp=(pCO)(pH2O)/(pH2)(pCO2)
= 11×11/8.70×8.70
=1.60
predict the charge on the predominant species of the peptide e−d−k−r−a−s−t at ph 5.0 .
At pH 5.0, the predominant species of the peptide E-D-K-R-A-S-T has a net positive charge of +2.
To predict the charge on the predominant species of the peptide E-D-K-R-A-S-T at pH 5.0, we need to consider the pKa values of the amino acids involved and the pH of the solution. The pKa values represent the acidity or basicity of the functional groups present in the amino acids.
1. At pH 5.0, the carboxyl group of glutamic acid (E) and aspartic acid (D) will be protonated, resulting in a positive charge on these amino acids. So, E and D will have a positive charge.
2. Lysine (K), arginine (R), histidine (H), and the N-terminus of the peptide have amino groups that can act as bases. At pH 5.0, these amino groups will be protonated, resulting in a positive charge on K, R, H, and the N-terminus.
3. Threonine (T), serine (S), and the C-terminus of the peptide do not have ionizable groups at pH 5.0 and will remain uncharged.
Therefore, at pH 5.0, the predominant species of the peptide E-D-K-R-A-S-T will have a net positive charge due to the protonation of E, D, K, R, H, and the N-terminus. The charge can be represented as follows:
E-D-K-R-A-S-T (at pH 5.0): 2+
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What mass of iron (ciron= 0.11 cal/g°C) would need 1450 cal of energy in order to raise its temperature by 19.7°C
Answer: m=Q/c*\Delta TQ/c∗ΔT = 1450cal/(0.11cal/g* 19.7ºC)=669.12 g1450cal/(0.11cal/g∗19.7ºC)=669.12g
Answer: 669.12g iron.
Explanation: