Can someone help me please?!!!!!
Answer: C, B, D (not sure about this one sorry) and C
Explanation:
How much water would I need to add to a 175 mL of a 0.45 M KOH solution to make a 0.2 M solution?
Answer:
393.75mL
Explanation:
We know that
C1V1= C2V2
where C = centration, V= volume
C1= 0.45 M
V1= 175 mL = 0.175 L
C2 = 0.2M
⇒V2= C1V1/C2
⇒V2 = 0.175×0.45/0.2
=0.39375L
Therefore, amount of water needed= 393.75mL
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
Give the following acid/base reaction:
HI(aq) + NH3(aq) ↔ NH4+(aq) + I-(aq)
Determine which substance is the acid, base, conjugate acid, and conjugate base.
Column A Column B:
1. Acid 1: I-
2. Base 2: HI
3. Conjugate base 3: NH3
4. Conjugate acid 4: NH4+
Answer:
6=100
Explanation:
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.
What does the symbol NaCl(aq) mean?
Answer:
The (aq) means that the NaCl is dissolved in water.
Explanation:
Answer:
A water-based solution of sodium chloride
Explanation:
ck12
Determine from the balanced chemical reaction if
the derived mole ratio is correct or incorrect.
2FeBr3 + 3Na2S → Fe2S3 + 6NaBr
2 moles FeBra
3 moles Na2S
Answer:
Correct
Explanation:
According to the balanced chemical reaction, 2 mol FeBr3 are consumed for every 3 mol Na2S consumed.
A balanced equation obey the law of conservation of mass. The coefficients are the numbers which are added to balance the chemical equation. Here the given mole ratio is correct.
What is a balanced equation?An equation in which the number of atoms of reactants and products on both sides of the equation are balanced is defined as the balanced chemical equation. The coefficients which are added in front of the formula of each component represents the number of the species.
A molar ratio denotes the ratio between the amounts in moles of any two compounds involved in a balanced chemical reaction. By comparing the coefficient of each component, the mole ratio can be determined.
Here for the given reaction, for every 3 moles of Na₂S consumption 2 moles of FeBr₃ is also consumed. So the molar ratio of Na₂S to FeBr₃ is 2/3. Molar ratios are used as the conversion factors between products and reactants in many chemistry problems.
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What body system changes the food we eat into energy?
Answer:
We need food to fuel our bodies for energy, growth and repair. The digestive system converts the foods we eat into their simplest forms, like glucose (sugars), amino acids (that make up protein) or fatty acids (that make up fats).Explanation:
hopes its right
This is agree or disagree I need help ASAP!!
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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A pH scale has how many sections on it?
Answer:
0-14
Explanation:
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 .....
what do you call a solid which dissolves?
Answer:
solute
Explanation:
for example sugar salt etc
solute dissolve in solvent
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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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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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:
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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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 the pH when h+=0.045 M?
Answer:
pH≈1.35
Explanation:
-log(0.045)≈1.35
A bowling ball rests on the floor. The bowling ball is given a push.
Which of the following is the most likely change to happen to the bowling ball?
It will move.
It will gain mass.
It will change colors.
It will change shape.
Answer:
A. It will move.
HELPPPP PLEASEE 50 POINTS
A graph labeled Solubility versus Temperature for a variety of salts has Temperature from 0 to 100 on the x axis and solubility in grams per 100 grams of water from 0 to 90 on the y axis. 5 solutes are shown. All data are approximate. Upper N a Upper C l starts at (0, 35) and rises evenly across the graph to (100, 40). Upper N a Subscript 2 Baseline Upper H Upper A s Upper O Subscript 4 Baseline starts at (0, 8), and rises steadily through (30, 38) to (80, 85). Upper B a (Upper N Upper O Subscript 3) Subscript 2 Baseline starts at (0, 5) and rises steadily across the graph to (100, 33). Upper N a Subscript 2 Baseline Upper S Upper O Subscript 4 Baseline starts at (0, 5), curves up steeply to (30, 50), and declines slowly to (100, 43). Upper C e Subscript 2 Baseline (Upper S Upper O Subscript 4) Subscript 3 Baseline times 9 Upper H Subscript 2 Baseline Upper O starts at (0, 19), falls to (20, 10), and continues to decline to (100, 0).
What is the solubility of Na2HAsO4 at 60°C?
20 g/100 mL of water
46 g/100 mL of water
65 g/100 mL of water
70 g/100 mL of water
Answer:
65 g/100 mL of water
Explanation:
Answer:
65g/100ml of water.
Explanation:
Edge 2021.
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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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
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 element would you expect to have the highest electronegativity?
Answer:
Fluorine
Explanation:
It's tendency to gain electron is higher than Ca and P
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.
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:
Which of the following compounds, sodium bicarbonate or water, should be used to extinguish a grease fire?
Answer:Douse the fire with baking soda: The chemical compound sodium bicarbonate, commonly called baking soda, is effective for extinguishing this type of fire. It takes a lot of baking soda to smother a grease fire, so pour it on while the flames are still small for the greatest effect
Explanation:
The grease fire has been put down by the addition of sodium bicarbonate as the extinguisher.
Grease fire has been defined as the fire that has been started with the over heating of the cooking oil at home. The fire has been started with the burning of the flammable liquids.
Extinguishing Grease fireThe fire in the cooking oil has been controlled with the addition of the sheet over the fire and turning off the flame.
The addition of water to grease fire results in the splashing of water over the fire and the spreading, resulting in the hazardous effects.
The sodium bicarbonate or baking soda has been used to put down grease fire.
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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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please help me ASAP!
Answer:
let me tell u what ASAP stands for Explanation: