Answer:
Temperature is not a chemical change because when a substance changes in temperature, its chemical makeup is not changing.
Primary succession is most likely caused by?
Answer:
volcanic eruption.
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Which refers to the density of the medium’s particles at the compression of a sound wave? A.amplitude B.pitch C.volume D.wavelength
Answer:
A is the answer.
Explanation:
The sound wave is a longitudinal wave which travels in the form of compression and rarefaction . The point where the particles are closer to each other is called compression and the point where the particles are far apart from each other is called rarefaction.
Answer:
Amplitude
Explanation:
Amplitude describes the displacement of the medium's particles. The higher the amplitude, the more dense it is, and the lower the amplitude, the less dense it is.
Pitch is incorrect because it describes the sound
Volume is incorrect because it describes the sound.
Wavelength is incorrect because it describes the distance between a period of a wave.
Molecular formula of ammonia
Answer:
NH3 is the molecular formula of ammonia
Explanation:
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How does the government control scientific research
Answer:
The government allocates a budget for research every year. The spending of that money is determined by government priorities. Some of the money is spent directly, in government-funded research centers.
Other money is distributed to other research institutions.
Money spent by other institutions for research has no government oversight.
Explanation:
(Help please!!! important question!!!) A neutral atom has an atomic number of 20 and a mass number of 41; how many protons, neutrons, and electrons are found within the atom? (2 points) 21 protons 21 electrons and 20 neutrons, 20 protons 20 electrons and 21 neutrons, 1 protons 20 electron and 20 neutrons, 41 protons 41 electrons and 20 neutrons
Answer: 20 protons,20 electrons and 21 neutrons
Explanation: because the number of protons is the same as the atomic number, and if the atom is neutral it has the same number of protons and electrons. if the mass number is 41 it means that there are 21 neutrons because to find the mass number you have to add protons and neutrons, so 20 + 21 = 41 and to confirm it the neutrons have been subtracted from the mass number and the atomic number, so 41-20 = 21
What mass of nickel (Ni) is in a 2.4 Kg sample of propanol if the concentration is 20 ppb ? (atomic mass of Ni = 58.69)
Answer:
The mass of nickel is 48μg
Explanation:
Parts per billion is a way to describe small concentrations and is defined as the ratio between μg of solute and kg of solvent.
If a solution of nickel in propanol is 20ppb, contains 20μg of nickel in 1 kg of propanol.
Thus, a sample of 2.4kg of propanol will contain:
2.4kg × (20μg nickel / 1kg) = 48μg nickel
The mass of nickel is 48μgSet up the ion formation equations, with ionization energy values for each electron in the valence layer, of the atoms of the chemical elements below: a) Na z=11 b) Ca z= 20 c) Sr z 38 d) Li z= 3 e) Cs z= 55 f) Be z= 43
Answer:
according to quantum physics newtons 3rd law is in the state of nuclear power things so the answer is c
Explanation:
according to quantum physics newtons 3rd law is in the state of nuclear power things so the answer is c
name the bleaching agent for cloth
Hydrogen peroxide is one of the most common bleaching agents. It is the primary bleaching agent in the textile industry, and is also used in pulp, paper, and home laundry applications.
bleaching agent is a material that lightens or whitens a substrate through chemical reaction. The bleaching reactions usually involve oxidative or reductive processes that degrade color systems. These processes may involve the destruction or modification of chromophoric groups in the substrate as well as the degradation of color bodies into smaller, more soluble units that are more easily removed in the bleaching process. The most common bleaching agents generally fall into two categories: chlorine and its related compounds (such as sodium hypochlorite) and the peroxygen bleaching agents, such as hydrogen peroxide and sodium perborate. Reducing bleaches represent another category. Enzymes are a new category of bleaching agents. They are used for textile, paper, and pulp bleaching as well as for home laundering. Chlorine‐containing bleaching agents are the most cost‐effective bleaching agents known. They are also effective disinfectants, and water disinfection is often the largest use of many chlorine‐containing bleaching agents. They may be divided into four classes: chlorine, hypochlorites, N‐chloro compounds, and chlorine dioxide. Except to bleach wood pulp and flour, chlorine itself is rarely used as a bleaching agent. The principal form of hypochlorite produced is sodium hypochlorite. Other hypochlorites include calcium hypochlorite and bleach liquor, bleaching powder and tropical bleach. The principal solid chlorine bleaching agents are the chlorinated isocyanurates, eg, sodium dichloroisocyanurate dihydrate. Other N‐chloro compounds include halogenated hydantoins, and sodium N‐chlorobenzenesulfonamide (chloramine B). Chlorine dioxide is a gas that is more hazardous than chlorine. Large amounts for pulp bleaching are made by several processes in which sodium chlorate is reduced with chloride, methanol, or sulfur dioxide in highly acidic solutions by complex reactions. Hydrogen peroxide is one of the most common bleaching agents. It is the primary bleaching agent in the textile industry, and is also used in pulp, paper, and home laundry applications. Hydrogen peroxide reacts with many compounds, such as borates, carbonates, pyrophosphates, sulfates, etc, to give peroxy compounds or peroxyhydrates. Peracids have superior cold water bleaching capability versus hydrogen peroxide because of the greater electrophilicity of the peracid peroxygen moiety. Lower wash temperatures and phosphate reductions or bans in detergent systems account for the recent utilization and vast literature of peracids in textile bleaching. The reducing agents generally used in bleaching include sulfur dioxide, sulfurous acid, bisulfites, sulfites, hydrosulfite (dithionites), sodium sulfoxylate formaldehyde, and sodium borohydride. These materials are used mainly in pulp and textile bleaching.
You arrive at a crime scene and are told the body of the victim is in the 10 m deep pool. You walk over to what you are told is a 12 m in diameter, cylindrical pool. From the outside of the pool, you can see that the body looks badly burnt. Your partner says, “It looks like our victim had been burned alive and tried to put out the fire by jumping in the pool. The victim likely drowned to death.”
Something does not sit right with you though. If there was a fire, where did it start? There are no signs of combustion anywhere. You aren’t so sure and ask the crime scene investigator to run a sample of the pool water before letting anybody try to pull the body out.
The CSI comes back to you and tells you that normal pool water pH is roughly around 7.2, but the pool pH is actually highly basic at a level of 13 with a concentration of hydroxide ions at 1.0 x 10-1 mol/L. It becomes obvious to you that the body wasn’t burned before going in to the pool , but AFTER and there was no fire needed!
You order the body to be removed from the pool, but the CSI interjects, “It would be too dangerous with a pH that high. I suggest you get some vinegar from the store and pour it in to the pool before hand to drop the pH to 7. Draining the pool would take far too long and we need to examine the body as soon as possible.” She asks one of your constables to go to the store to purchase 5 – 4L jugs of vinegar (pH = 2) to pour in the pool, as she states it is enough to bring the pH to a safe level of 7.
It sounds like it could be enough vinegar based on your knowledge of acids and bases, but you want to double-check her estimate before sending your constable to the store. Verify whether or not she is correct using calculations. A diagram may help you with your calculations.
Hint 1: 1m3 = 1000L
Hint 2: Vcylinder = πr2h
Answer:
The vinegar is not enough to neutralize the pool.
Explanation:
The [OH⁻] in the pool is 1.0x10⁻¹mol / L. To know how many moles of OH⁻ are in the solution, you must calculate volume of the pool thus:
V(pool) = πr²h
Where r, radius is d/2 = 12m/2 = 6m and h is deep of the pool = 10m
V(pool) = π(6m)²*10
V(pool) = 1131m³
As 1m³ = 1000L:
1131m³ × (1000L / 1m³) = 1131000L in the pool.
And moles of OH⁻ are:
1.0x10⁻¹mol / L ₓ 1131000L = 131100 moles of OH⁻ are in the pool
The neutralization of OH⁻ with H⁺ is:
OH⁻ + H⁺ → H₂O
That means to neutralize the pool you must add 131100 moles of H⁺.
The H⁺ concentration in a vinegar pH = 2 is:
pH = -log [H⁺]
2 = -log [H⁺]
1x10⁻²M = [H⁺]
4L are just 4x10⁻² moles of [H⁺]. As you need 131100 moles of H⁺:
The vinegar is not enough to neutralize the pool.The mass of .10 moles of iron is:
Answer:
so mass in gram=560grams
Explanation:
number of moles=10moles
molar mass=56grams/moles
mass in gram of Fe=?
as we know that
[tex]number of moles=\frac{mass in gram}{molar mass}[/tex]
evaluating the formula
number of moles×molar mass=mass in gram
mass in gram=10moles×56grams/moles
mass in gram=560grams
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5.What is the chemibal formula for lead (II) iodide
Answer: The chemical formula for lead (II) iodide is [tex]PbI_2[/tex]
Explanation:
Lead (II) iodide is a ionic compound because it are formed by transference of electrons between metals and non metals.The bond formed between a metal and a non-metal is always ionic in nature.
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
The nomenclature of ionic compounds is given by:
1. Positive is written first followed by the oxidation state of metal in roman numerals in square brackets.
2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.
The chemical formula for lead (II) iodide is [tex]PbI_2[/tex]
Which of the following is an amorphous solid?
O
A. Diamond
B. Graphite
O C. Glass
O D. Iron
Answer:
C. Glass
Explanation:
Amorphous solids have a non-crystalline structure and no order. In that case, Diamonds, Graphite, and Iron all have a crystalline structure and order. You are left with C as your answer.
Which compound can be used to preserve biological specimens? A central C is double bonded to an O, and single bonded to 2 H. A chain, reading from left: C H 3 bonded to C, bonded to O, bonded to C H 2, bonded to C H2, bonded to C H 3. The single C near the beginning of the chain is double bonded to O. C H 3 single bonded to C, which is double bonded above right to O, and below right to C H 2, which is bonded to C H 3. A central C is double bonded to an O above, and single bonded to C H 3 below left and O H below right.
Answer:
A central C is double bonded to an O, and single bonded to 2 H
Explanation:
Methanal, also known as formaldehyde, is a chemical compound used to preserve dead biological specimens for further study. It is called formalin when in a solution and it helps keep specimens in a fresh state by hardening the tissues of the specimen involved.
Formaldehyde is a gaseous compound that has an aldehyde functional group i.e. -CHO and has a chemical formula, H-CHO or CH2O as described in the question that a central C is double bonded to an O, and single bonded to 2 H (see attached image for structural formula).
The chemical for the preservation of biological specimens has consisted of central C with a double-bonded O and two single-bonded hydrogens. Thus, option A is correct.
The biological compound that has been used to preserve biological specimens has been methanal. It has been the simplest aldehyde. The chemical formula of formaldehyde, also known as methanal has been H-CHO.
The structure of formaldehyde has been consisted with single bond between H and C. The central carbon has been associated with a double bond between the C and O, with single-bonded H.
Thus, the chemical for preservation of biological specimen has been consisted of central C with a double-bonded O and two single-bonded hydrogens. Thus, option A is correct.
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what is meant by amoeba and what is the name of its parts
Answer:
amoeba is the unicellular organism which can be seen by only microscope but not with our nacked eyes
Answer:
An amoeba often called an amoeboid, is a type of cell or unicellular organism which has the ability to alter its shape, primarily by extending and retracting pseudopods Amoebae do not form a single taxonomic group; instead, they are found in every major lineage of eukaryotic organisms. Amoeboid cells occur not only among the protozoa, but also in fungi, algae, and animals.
name of parts of ameoba
3 parts – the cytoplasm, plasma membrane and the nucleus. The cytoplasm can be differentiated into 2 layers – the outer ectoplasm and the inner endoplasm. The plasma membrane is a very thin, double-layered membrane composed of protein and lipid molecule
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sodium chloride is called an electrovalent compound where as carbon dioxide is called covalent compound why
Electrovalent compounds are those that are created when one or more electrons are transferred from one atom to another inside the compound. NaCl is an electrovalent substance because it shares an electron with other compounds to produce them.
What are compounds ?A material created by chemically joining two or more distinct components. Examples of compounds are table salt (NaCl), which is generated from the elements sodium and chloride, and water (H2O), which is created from the components hydrogen and oxygen.
One carbon atom and two oxygen atoms combine to form carbon dioxide. One carbon dioxide molecule contains four covalent connections. Because neither carbon nor oxygen are metals, we can infer that carbon dioxide is a covalent molecule.
Pure substances known as compounds are created chemically when two or more elements are combined in a specific mass proportion. Chlorine and sodium combine to form sodium chloride (common salt).
Thus, sodium chloride is called an electrovalent compound whereas carbon dioxide is called covalent compound.
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Which of the following is the best definition of a physical change?
A. Something that can be observed or measured while changing the identity of the substance.
B. A nail rusting.
C. A change that occurs without changing the identity of the substance.
D. Ice melting into water.
Answer:
the answer is D.ice melting into water
At what angle(s) should investigators photograph a tool mark? A. parallel B. perpendicular C. 45 degrees D. varying
Answer:
B
Explanation:
Consider an electrochemical cell based on the spontaneous reaction 2AgCl(s) + Zn(s) → 2Ag(s) + 2Cl– + Zn2+. If the zinc ion concentration is kept constant at 1 M, and the chlorine ion concentration is decreased from 1 M to 0.001 M, the cell voltage should:
Answer:
there is an increase by 0.18 V in the cell voltage.
Explanation:
The given equation of the reaction can be well written as
[tex]2AgCl_{(s)} + Zn _{(s)} \to 2Ag_{(s)} + 2 Cl^- _{(aq)}+ Zn^{2+}_{(aq)}[/tex]
By application of Nernst Equation ; we have the expression
[tex]E_{cell} = E^0- \dfrac{0,059}{n}log (\dfrac{[product]}{[reactant]})[/tex]
here in the above equation;
n = number of electrons transferred in the equation of the reaction
n = 2
Also;
[tex]E^0 = E_{cathode} - E_{anode}[/tex]
[tex]E^0 = E_{Ag^+/Ag} - E_{Zn^+/Zn}[/tex]
[tex]E^0 = +(0.80 \ V) - (-0..76 \ V)[/tex]
[tex]E^0 = (0.80 \ V +0..76 \ V)[/tex]
[tex]E^0 = 1.56 \ V[/tex]
If the zinc ion concentration is kept constant at 1 M; we have:
[tex]E_{cell} = E^0- \dfrac{0.059}{n}log (\dfrac{[product]}{[reactant]})[/tex]
[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log ({[Zn^{2+} ]}{[Cl^{2-}]})[/tex]
[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log (1)[/tex]
Since log(1) = 0
Therefore;
[tex]E_{cell} = 1.56\ V[/tex]
When the chlorine ion concentration is decreased from 1 M to 0.001 M; we have;
[tex]E_{cell} = E^0- \dfrac{0.059}{n}log (\dfrac{[product]}{[reactant]})[/tex]
[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log ({[Zn^{2+} ]}{[Cl^{2-}]})[/tex]
[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log ({[1*0.001^2}]})[/tex]
[tex]E_{cell} = 1.56 - 0.0295 \ * \ log ({[1*10^{-6}}]})[/tex]
[tex]E_{cell} = + 1.737 \ V[/tex]
The change in voltage = [tex]E_{cell} - E^0[/tex]
=( 1.737 - 1.56 )V
= 0.177 V
≅ 0.18 V
Thus; from the following observation; there is an increase by 0.18 V in the cell voltage.
The voltage of the cell increased by 0.18 V.
The equation of the reaction is; 2AgCl(s) + Zn(s) → 2Ag(s) + 2Cl– + Zn2+
We know that;
E°cell = 1.36 - (-0.76) = 2.12 V
If the cells are both at 1M concentration the Ecell = E°cell = 2.12 V
When the concentration of Cl- decreased from 1 M to 0.001 M
Ecell = E°cell - 0.0592/n log Q
Substituting values;
Ecell = 2.12 V - 0.0592/2 log (1 × (0.001)^2)
Ecell = 2.298 V
Increase in voltage = 2.298 V - 2.12 V = 0.18 V
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What is the Ka of a 1.9 ~ 10-2 M
solution of carbonic acid (H2CO3)
with a pH of 3.88?
Ka = [ ? ] × 10!?)
Helllllp
Answer:
Ka = 9.2x10⁻⁷
Explanation:
The equilibrium of carbonic acid in water is:
H₂CO₃ ⇄ HCO₃⁻ + H⁺
Where Ka is defined as:
Ka = [HCO₃⁻] [H⁺] / [H₂CO₃]
The equilibrium concentration of the species is:
[H₂CO₃] = 1.9x10⁻² - X
[HCO₃⁻] = X
[H⁺] = X
As pH is -log[H⁺]
3.88 = -log[H⁺]
1.318x10⁻⁴ = [H⁺] = X
Replacing:
[H₂CO₃] = 1.9x10⁻² - 1.318x10⁻⁴ = 1.8868x10⁻²
[HCO₃⁻] = 1.318x10⁻⁴
[H⁺] = 1.318x10⁻⁴
Replacing in ka equation:
Ka = [1.318x10⁻⁴] [1.318x10⁻⁴] / [1.8868x10⁻²]
Ka = 9.2x10⁻⁷Answer: 9.2 x 10^-7
Explanation:
Which sequence represents the relationship between pressure and volume of an ideal gas as explained by the kinetic-molecular theory? more gas particles Right arrow. More collisions Right arrow. Higher pressure smaller volume Right arrow. Crowded particles Right arrow. Less collisions Right arrow. Lower pressure smaller volume Right arrow. Crowded particles Right arrow. More collisions Right arrow. Higher pressure more gas particles Right arrow. More kinetic energy Right arrow. More volume Right arrow. Higher pressure
Answer:
smaller volume ⇒ Crowded particles ⇒ More collisions ⇒ Higher pressure
Explanation:
Smaller the volume , more crowed the particles . Then the particles will have rapid collisions so the free mean path is decreased , hence the pressure will be increased as follows
[tex]P=\frac{K_bT}{\sqrt{2}\pi d^2\lambda }[/tex]
where λ is mean free path , P is pressure .
The sequence the represent the relationship between pressure and volume of an ideal gas is: smaller volume right arrow Crowded particles right arrow More collisions right arrow Higher pressure
The kinetic molecular theory made five postulates which are used to explain the behaviour of gases.
From the postulates, he uses the kinetic molecular theory to explain Boyle's Law because the majority of a gas's volume in space is usually empty and may be compressed.
So, when a gas is compressed without affecting its temperature, the average kinetic energy of the gas particles remains constant. The particles continue to flow at the same rate, but the container has reduced.
As a result, the particles go from one end of the container to another in less time. This suggests they're hitting the barriers (collision) more frequently. Each and every increase in the frequency of collisions with the walls, thus, results in an increase in the gas's pressure.
Hence, as the volume of a gas decreases, the pressure of the gas increases.
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help help please help me I need the answer ASAP
Solution A has a mass of 70g. Solution B has a mass of 35 g. when they are mixed, a chemical reaction occurs in which a gas is produced. if the mass of the final mixture is 90g, what mass of gas was produced???
Answer:
15 g
Explanation:
1. According to the Law of Conservation of Mass, the sum of the products should be 105 g because 70 g + 35 g = 105 g.
2. If 90g of solution was produced and there's supposed to be 105 g, then the remaining grams would be equal to the mass of the gas.
3. 105 g - 90g = 15 g
A glass cup of orange juice is found to have pOH of 11.40. Calculate the concentration of the hydrogen ions in the juice.
Answer: The concentration of hydrogen ion is 2.5 x 10∧-3.
Explanation:
It is well known that; pH + pOH = 14
∴ pH + 11.40 = 14
pH = 14 -11.40 = 2.60
Remember that,
pH = - Log [ H+ ]
2.60 = - log [H+]
To get the hydrogen ion concentration, we take the anti-log of 2.60.
[H+] = Antilog 2.60 = 2.5 x 10∧-3.
what is the mass of 1.5 mol of aluminum?
Answer:
40.47 g Al
Explanation:
In 1 mol of Al, there are 26.98 grams of Al, so Al is 26.98 g/mol.
Simply multiply 1.5 by 26.98 to get your answer.
To increase the current in a circuit, which can be increased? A. voltage B. resistance C. interference D. ohms
Answer:
voltage I'm just guessing
Answer:
Option A
Explanation:
Looking at the following formula:
I = V/R
Where V is voltage, I is current and R is resistance
In the above equation, Current and Voltage are in direct relationship such that if I is increased , V is also increased and vice versa. So, To increase the current, voltage should be increased.
A mixture is best described as:
A. None of these
B. A pure chemical substance consisting of one type of atom.
OC. The basic building blocks of matter.
D. Two or more elements or compounds that are mixed together but not chemically bonded.
Answer:
D. Two or more elements or compounds that are mixed together but not chemically bonded.
Explanation:
Mixture is unique as it is not chemically bonded and individual entities such as elements or compounds keep their unique identities.
Answer:
Mixture consists of two or three elements or compounds that are mixed together but not chemically bonded.
Next, break down the equation shown into the skeletal half-reactions for oxidation and reduction. Which of
these pairs shows the two skeletal half-reactions with their correct assignments?
reduction half reaction: HNO, NO
oxidation half reaction SH,SO,
oxidation half reaction: HNO3 -> NO
reduction half reaction: SH2SO,
reduction half reaction: HNO3 -H,SO,
oxidation half reaction S -> H2SO4
Answer:
Its answer A
Explanation:
I just took the test
Answer:
A:
reduction half reaction: HNO3-> NO
oxidation half reaction S->H2SO4
Explanation:
The initial temperature of a bomb calorimeter is 28.50°C. When a chemist carries out a reaction in this calorimeter, its temperature decreases to 27.45°C. If the calorimeter has a mass of 1.400 kg and a specific heat of 3.52 J/(gi°C), how much heat is absorbed by the reaction?
Answer:
D. 5,170 J
Explanation:
A balloon has a volume of 0.56 L and a pressure of 1.34 atm. The balloons pressure decreased to 0.85 atm,
what is the balloons new volume? Write your solution, including the formula used.
Answer:
[tex]\large \boxed{\text{0.88 L}}[/tex]
Explanation:
The temperature and amount of gas are constant, so we can use Boyle’s Law.
[tex]p_{1}V_{1} = p_{2}V_{2}[/tex]
Data:
[tex]\begin{array}{rcrrcl}p_{1}& =& \text{1.34 atm}\qquad & V_{1} &= & \text{ 0.56 L} \\p_{2}& =& \text{0.85 atm}\qquad & V_{2} &= & ?\\\end{array}[/tex]
Calculations:
[tex]\begin{array}{rcl}\text{1.34 atm} \times \text{0.56 L} & =& \text{0.85 atm} \times V_{2}\\\text{0.750 L} & = & 0.85V_{2}\\V_{2} & = &\dfrac{0.750}{0.85}\\\\& = &\textbf{0.88 L}\\\end{array}\\\text{The balloon's new volume is $ \large \boxed{\textbf{0.88 L}}$}[/tex]
15 Ethanoic acid reacts slowly with calcium carbonate.
Which statements explain why an increase in temperature increases the rate oft
1
The activation energy of the reaction is decreased.
2
There is an increase in collision rate.
3
The particles have more energy.
4
There will be fewer successful collisions.
А
1 and 2
B
1 and 3
с
2 and 3
D
2 and 4
Answer:
C
2and3
Explanation:
increase in temperature causes the particles to gain more energy
Which consists of only one type of atom?
Answer:
A chemical element
Explanation:
A chemical element consists of only one type of atom.