Answer:
A. a mixture
Explanation:
hope this helps
A 20 ml of 0.27M of solution of the salt NaA has a pH of 8.70. Calculate the pKa value of the acid HA.
Answer:
pKa = 3.97
Explanation:
Let's state the equations:
NaA → A⁻ + Na⁺
A⁻ + H₂O ⇄ OH⁻ + HA Kb
We don't have the concentration of [OH⁻] but we do know pH, so we can determine, pOH and after that, [OH⁻].
14 - pH = pOH → 14 - 8.70 = 5.30
10^-pOH = [OH⁻] → 10⁻⁵'³⁰ = 5.01×10⁻⁶ M
Initially we can know, the moles of base, we had.
20 mL . 0.27M = 5.4 mmoles. So now, let's make the expression for Kb.
Kb = [OH⁻] . HA / [A⁻]
As the [OH⁻] is so low, we can assume, there where no loses and the salt is well concentrated. So:
Kb = (5.01×10⁻⁶)² / 0.27 → 9.29×10⁻¹¹
Kw = Ka . Kb, then Ka = Kw/ Kb
Ka = 1×10⁻¹⁴ /9.29×10⁻¹¹ = 1.08×10⁻⁴
pKa = - log Ka → - log 1.08×10⁻⁴ = 3.97
Which of the following is an example of a tissue A chloroplast
B stomach
C human
D bone
Answer:
In plants, chloroplasts occur in all green tissues, though they are concentrated particularly in the parenchyma cells of the leaf mesophyl. An example of a chloroplast is a cell in algae that consumes carbon dioxide and releases oxygen while creating sugar. A plastid that contains chlorophyll and is found in the cells of green plants and algae.
Explanation:
please mark brainlest
Answer: I would say C or D.
Explanation: Maybe because there are four main tissue types in the body: epithelial, connective, muscle, and nervous. Each is designed for specific functions.
In chloroplast it is the structure within the cells of plants and green algae.
In stomach tissue has a thin simple columnar epithelial layer for secretion and absorption.
In bone tissue it is tissue that gives strength and structure to bones. Bone is made up of compact tissue (the hard, outer layer) and cancellous tissue (the spongy, inner layer that contains red marrow). Bone tissue is maintained by bone-forming cells called osteoblasts and cells that break down bone called osteoclasts.
Please help me classify properly.
Answer:C
Explanation:
Homogeneous Mixture
Answer:
homogeneous mixture
Explanation:
it is the same throughout so therefore it can be separated
The equilibrium constant, Kc, for the reaction below is 0.10 at 25oC. Find the equilibrium concentration of chlorine gas, Cl2(g), if the equilibrium concentrations of ICl(g) and I2(g) are known to be 0.50 M and 0.40 M respectively.
2 ICl(g) → Cl2(g) + I2(g)
Answer:
The equilibrium concentration of chlorine gas, Cl₂(g), is 0.0625 M
Explanation:
Chemical equilibrium is established when there are two opposite reactions that take place simultaneously at the same speed, so that no changes are observed as time passes, despite the fact that the substances present continue to react with each other.
The mathematical expression that represents Chemical Equilibrium is known as the Law of Mass Action and is stated as: The ratio of the product of high concentrations to the stoichiometric coefficients in the reaction of products and reactants remains constant at equilibrium. For any reaction:
aA + bB ⇄ cC + dD
the equilibrium constant Kc is calculated as:
[tex]Kc=\frac{[C]^{c} *[D]^{d} }{[A]^{a} *[B]^{b}}[/tex]
In this case, you have:
2 ICl(g) → Cl₂(g) + I₂(g)
So, the equilibrium constant Kc is:
[tex]Kc=\frac{[Cl_{2} ]*[I_{2} ]}{[ICl]^{2} }[/tex]
Being:
Kc= 0.10[Cl₂]= ?[ICl]= 0.50 M[I₂]= 0.40 MReplacing:
[tex]0.1=\frac{[Cl_{2} ]*0.40 M}{(0.50 M)^{2} }[/tex]
Solving:
[tex]0.1=\frac{[Cl_{2} ]*0.40 M}{0.25 M^{2} }[/tex]
0.1= 1.6 [tex]\frac{1}{M}[/tex]* [Cl₂]
[Cl₂]= 0.1 ÷ 1.6 [tex]\frac{1}{M}[/tex]
[Cl₂]= 0.0625 M
The equilibrium concentration of chlorine gas, Cl₂(g), is 0.0625 M
The equilibrium concentration of chlorine gas, if the equilibrium concentrations of ICl(g) and I₂(g) are known to be 0.50 M and 0.40 M respectively is 0.0625M.
How we calculate the equilibrium constant?Equilibrium constant for any reaction will be define as the ratio of the concentration of products to the concentration of reactants with raise to their respective coefficients.
Given chemical reaction is:
2ICl(g) → Cl₂(g) + I₂(g)
Equilibrium constant for this reaction will be calculated as:
Kc = [Cl₂][I₂] / [ICl]², where
Kc = equilibrium constant = 0.10
[I₂] = concentration of iodine gas = 0.40 M
[ICl]² = concentration of ICl = 0.50 M = (0.50M)² = 0.25M²
[Cl₂] = concentration of chlorine gas = to find?
On putting all these values on the above equation and calculate for the value of [Cl₂] as follow:
[Cl₂] = Kc × [ICl]² / [I₂]
[Cl₂] = (0.10)(0.25) / (0.40)
[Cl₂] = 0.0625M
Hence, equilibrium concentration of chlorine gas is 0.0625M.
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In a transverse wave, this is the magnitude of height of a wave from origin to crest.
In a longitudinal wave, this is corresponds to how much the wave is compressed, as compared to areas of little compression.
a transverse wave, this is the magnitude of height of a wave from origin to crest. In a longitudinal wave, this is corresponds to how much the wave is compressed, as compared to areas of little compression. This is wave whose energy travels in the same direction as the energy is transferred
In a transverse wave, amplitude is the magnitude of height of a wave from origin to crest. In a longitudinal wave, crest is corresponds to how much the wave is compressed
What are waves?A wave is a dynamic disturbance of one or more quantities that propagates and is commonly described by a wave equation.
In transverse wave, magnitude of height of a wave from origin to crest part is called amplitude.In longitudinal wave, the part of the wave in which compression is occur will known as crest.Hence for the transverse wave that is amplitude and for the longitudinal wave that is crest.
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A 12.0 L balloon at 84 °C is cooled until it
becomes 5.0 L. To what temperature was
the balloon cooled?
The ideal gas relates the volume, pressure, and temperature to each other. The balloon was cooled to -120 degrees celsius.
What is Charle's law?Charle's law states the direct relationship between the volume and the temperature of the hypothetical gas. The law is given as,
[tex]\rm \dfrac{V_{1}}{T_{1}} = \rm \dfrac{V_{2}}{T_{2}}[/tex]
As it can be seen from the question the volume of the gas in the balloon is decreasing so the temperature will also decrease.
Given,
Initial volume = 12.0 L
Final volume = 5.0 L
Initial temperature = 357.15 K
The final temperature is calculated as:
[tex]\begin{aligned} \rm T_{2} &= \rm \dfrac{V_{2}T_{1}}{V_{1}}\\\\&= \dfrac{5\times 357.15}{12}\\\\&= 148.81\;\rm K\end{aligned}[/tex]
Therefore, -120 degrees celsius is the final temperature of the balloon.
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EASYYYYYY1
Compare and contrast a sanitary landfill and a secure landfill.
Answer:
Secure landfills Landfilling of hazardous solid or containerized waste is regulated more stringently than landfilling of municipal solid waste. Hazardous wastes must be deposited in so-called secure landfills, which provide at least 3 metres (10 feet) of separation between the bottom of the landfill and the underlying bedrock or groundwater table.
Explanation:
A student drops a white tablet into a glass of water, producing
carbon dioxide gas. This is a demonstration of
A. a change of state.
B. a chemical reaction.
C. the creation of matter.
O D. the movement of electricity.
Answer:
A chemical reaction
Explanation:
transmutation occurs during which type of radioactive decay
Explanation:
Transmutation, conversion of one chemical element into another. A transmutation entails a change in the structure of atomic nuclei and hence may be induced by a nuclear reaction (q.v.), such as neutron capture, or occur spontaneously by radioactive decay, such as alpha decay and beta decay (qq. v.).
Which set of elements represents a period within the Periodic Table?
H, He, Ar , Xe , Rn ,
N, P, As, Sb , Bi
K, V, Fe, Ga , Kr
La, Pa, Sm, Tb, Yb
what is the pH when h+=0.045 M?
Answer:
pH≈1.35
Explanation:
-log(0.045)≈1.35
Tropical, temperate, and taiga refer to what type of biomes?
A. grasslands
B. deserts
C. the tundra
D. forests
Answer:
From my view the answer is
D. Forests
Nitrogen-fixers are the critical links between ______.
A. atmospheric nitrogen and organisms that need nitrogen to survive
B. atmospheric nitrogen and the formation of new soil
C. atmospheric nitrogen and the formation of new atmospheric nitrogen
D. None of the above
Please answer correctly and explain
Nitrogen-fixers are the critical links between atmospheric nitrogen and organisms that need nitrogen to survive.
Where Nitrogen fixers are used?Nitrogen fixers are the compounds which are used in the nitrogen fixation process to convert the nitrogen molecule in other nitrogenous compounds.
So, the nitrogen fixers converts the atmospheric nitrogen molecule (N₂) into the other compounds like ammonia (NH₃) or any other useful nitrogenous compounds which will be used or absorbed by the soil or any other aquatic species. Some examples of nitrogen fixers are bacteria, clostridium, rhizobium, and many more.
Hence option (A) is correct i.e. atmospheric nitrogen and organisms that need nitrogen to survive.
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Which element would you expect to have the highest electronegativity?
Answer:
Fluorine
Explanation:
It's tendency to gain electron is higher than Ca and P
What is a type of radiation produced when the unstable nucleus of a radioactive element emits a helium nucleus?
A. deuterium radiation
B. beta radiation
C. alpha radiation
D. gamma radiation
Which is a correct set of values of m for one of the subshells of n = 2?
–1, 0, 1
–1, –2, 0, 1, 2
–1, –2, –3, 0, 1, 2, 3
–1, –2, –3, –4, 0, 1, 2, 3, 4
Answer:
-1, 0, +1
Explanation:
n = 2 n = 0,1,2,3,.................n
l= n-1 = 2-1 =1. l= 1,2,3,4....................n-1
m = l is 1 so now write the value of magnetic moment as -1,0,+1
for eg . if the value of l comes to 2 then u will write the value of m as -2,-1,0,+1,+2 .
i hope it will help u .....
please help me ASAP!
Answer:
let me tell u what ASAP stands for Explanation:
i need help i have a homework assignment to finish and this is the last question help please and thank u
Para solucionar el ejercicio primero se debe conocer el número atómico de los elementos para determinar cuantos electrones tiene cada uno N: número atómico 7, tiene 7 electrones Nivel 1: 2 electrones Nivel 2: 5 electrones P: número atómico 15, tiene 15 electrones Nivel 1: 2 electrones Nivel 2: 8 electrones Nivel 3: 5 electrones Cl: número atómico 17, tiene 17 electrones
Answer:
El número atómico se refiere al número de protones o electrones de un átomo.
Explicación:
El número atómico se refiere a la cantidad de protones o la cantidad de electrones que giran alrededor de las capas u órbita de un átomo, por lo que el número atómico 7 representa que el átomo tiene 7 electrones o protones mientras que, por otro lado, el número atómico 17 muestra el número de electrones o protón. Solo hay dos electrones que entran en la primera órbita y en el resto de las capas tiene espacio para 8 electrones por lo que los átomos pierden o agregan electrones en su capa más externa para obtener estabilidad.
At a hydroelectric power plant, potential energy is changed into kinetic energy. The kinetic energy is then transformed into electrical energy. i What is the source of the energy that turns the turbine in the power plant? Chemical energy of water molecules as they fall Gravitational potential energy of water behind the dam Elastic potential energy of the water molecules as they bounce over the dam Electrical energy from power lines that connect the hydroelectric plant to a grid
Answer:
Gravitational potential energy of water behind the dam
Explanation:
Energy can be defined as the ability (capacity) to do work. The two (2) main types of energy are;
a. Gravitational potential energy (GPE): it is an energy possessed by an object or body due to its position above the earth.
b. Kinetic energy (KE): it is an energy possessed by an object or body due to its motion.
Hydroelectric power plant refers to a renewable source of energy used for the generation of electricity, through the use of powerful hydraulic steam turbines operating at high voltage and are being driven by the energy acquired by water falling from a height and flowing through a penstock (pipe) i.e the mechanical energy (gravitational potential energy + kinetic energy).
At a hydroelectric power plant, potential energy is changed into kinetic energy. The kinetic energy is then transformed into electrical energy.
The source of the energy that turns the turbine in the power plant is Gravitational potential energy of water behind the dam, usually from streams or rivers.
Which type of stoichiometry problems does not require the use of molar mass?
Answer:
Explanation:
It is volume-volume problems that does not require the use of molar mass.
The thermal energy of matter increases when ___.
A. Heat flows of the matter
B. The mass of the matter decreases
C. Heat flows into the matter
D. The temperature decreases
Oxygen is the 16th element on the periodic table and the number of neutrons is 8. Using the formula A=Z+N, determine by calculation the atomic number for oxygen *
a. 6
b. 8
c. 24
d. 16
Answer:
the answer is twenty-four
What is a dominant trait and a recessive trait
Answer:
Dominant traits are always expressed when the connected allele is dominant, even if only one copy exists. Recessive traits are expressed only if both the connected alleles are recessive.
Explanation:
Freckles, cleft chin and dimples are all examples of a dominant trait.
A student performs an experiment with three unknown fluids and obtains the following measurements: Fluid A: m = 2060 g, V = 2000 mL Fluid B: m = 672 g, V = 850 mL
Fluid C: m = 990 g,
V = 1100 mL
Answer:
fluid - A is 1.03
fluid -B is 0.790
fluid - C is 0.90
Explanation:
In our exprimetal fluid, the density of
fluid - A is 1.03
fluid -B is 0.790
fluid - C is 0.90
The fluid with high density settles at bottom of the beaker and least dense fluid forms layer on the surface .
Fluid A is 1.03
Fluid B is 0.790
Fluid C is 0.90
What is measurment?Measurment is a process by which we can measure any physical quantity with the help of different apparatus. For example if one can want to measure the distance than he can use the a simple measuring scale.
Distance can be measured in kilometer,meter, centimeter etc. Temperature can be measured with the help of glass tube thermometer as glass tube is a simple temperature measuring appratus and glass tube thermometer is used to measure temperature in fahrenheit (F).
Measurment is a general process which can be used by a common person in his daily life. Every common thing which we use in our routine life need to be measured like if we buy sugar it will be measured in kilogram or gram. If a person buy milk it can measured in liter.
Therefore,Fluid A is 1.03
Fluid B is 0.790
Fluid C is 0.90
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Step 6: Measure Solubility in Boiling Water
110
100
80
100 ml
60
90
40
20
Temperature of the water to the nearest degree:
°C. DONE
Intro
Answer:
the answer is 102- i took did it on edg
Explanation:
The ability of a material, the solute, to combine with some other substance, the solvent, is known as solubility. Temperature of the water to the nearest degree is 110 °C for the given solubility.
The ability of a material, the solute, to combine with some other substance, the solvent, is known as solubility in chemistry. Insolubility, or the solute's inability to create such a solution, is the opposite property.
The concentration of a solute inside a saturated solution—a solution where no more solute could be dissolved—is typically used to gauge the degree of a substance's solubility in a particular solvent. Temperature of the water to the nearest degree is 110 °C for the given solubility.
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What are the chemical reactions involved in CO2 emission?
A certain concentration of water in the air is needed for the reactions that cause wood to decay. Furniture can rot away very quickly in the jungle Furniture high in the mountains usually does not rot easily. This data table shows the rates of decay for a wooden chair to rot away. What can you conclude about the rates of these reactions? Object Location Decay time Average concentration of water in the air Wooden chair Very low 300 to 500 years Rocky mountaintop Wooden chair Jungle High 5 to 20 years O A. Reactions occur at the same rate, no matter what the concentration of water in the air. O B. Reactions occur more quickly in air with a high concentration of water. O C. Reactions occur more slowly in air with a high concentration of water D. There is not enough information to conclude anything about the reaction rates
Reactions are faster when air contains a higher concentration of water.
High temperature and high relative humidity are very important factors that drive a reaction in which biomass decays. At high temperature and high relative humidity, decomposition occurs faster.
Hence, from the data presented, we can see that, reactions occur more quickly in air with a high concentration of water.
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what do you call a solid which dissolves?
Answer:
solute
Explanation:
for example sugar salt etc
solute dissolve in solvent
Please help!!
The diagram shows the electron configuration of an atom of an element for the electrons in the s and p orbitals.
What is the group number of the element in the periodic table?
A) 1
B) 2
C) 13
D) 15
Answer:
15
Explanation:
because since the outer shell has 5 electron then add 5 and 10 to get 15