Answer:
Ca, Zn, Ni, Al, Fe
Explanation:
The activity series is an arrangement of metals in order of decreasing reactivity.
Metals that are high up in the activity series are very reactive. They displace metals that are lower in the activity series from an aqueous solution of their salts.
The metals; Ca, Zn, Ni, Al, Fe are all above Pb in the activity series hence they will cause Pb2+ ions to come out of solution as solid Pb.
A more reactive metal displaces the less reactive metals in the solution. Ca, Al, Zn, and Fe can be accomplished to take out the [tex]\bold{ Pb^2^+}[/tex] from the solution as solid Pb.
Metal displacement Reaction:
In this type of reaction a more reactive metal displaces the less reactive metals in the solution.
The metal reactivity series
Ca > Al > Zn > Fe > Ni > Pb > Ag > Au
The lead ( Pb) is less reactive than the Ca, Al, Zn, and Fe.
Therefore, Ca, Al, Zn, and Fe can be accomplished to take out the [tex]\bold{ Pb^2^+}[/tex] from the solution as solid Pb.
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Determine whether each observation generally corresponds to a physical change or a chemical change. A liquid freezes into a solid. _________ Bubbles are produced upon mixing two solutions. __________ A precipitate is formed from two solutions. _________ A solution heats up upon mixing with another. ____________ A solid dissolves into water. __________ The color of a substance changes over time
Answer:
A liquid freezes into a solid or any other state change is a physical change. Bubbles are produced upon mixing two solutions is a Chemical change as gas formed. a precipitate is formed from two solutions is a Chemical change The conversion of a substance to another compound over time leads to a color change of the substance due to the insolubility of the compound.
It is a chemical change or properties. A solution that heats up upon mixing with another is a Chemical change known as an exothermic reaction. dissolving the substance in a liquid is a physical change physical that can be regained by evaporation or crystalization.
Sodium azide (NaN3) is a substance that can be used to inflate airbags. An electrical impulse causes the sodium azide to decompose, producing elemental sodium and nitrogen gas. Write the balanced chemical equation for this reaction.
Answer:
2NaN₃ → 2Na + 3N₂
Explanation:
First we use the information given by the problem to write an unbalanced equation:
NaN₃ → Na + N₂There are 3 N atoms on the left side and only 2 on the right, to remedy that we put a 2 coefficient on NaN₃ and a 3 coefficient on N₂:
2NaN₃ → Na + 3N₂Now there are 6 N atoms on both sides of the equation. What's left is to balance Na atoms:
2NaN₃ → 2Na + 3N₂The equation is now balanced.
The properly balanced chemical equation for this chemical reaction is given by [tex]2NaN_3 \rightarrow 2Na + 3N_2[/tex]
What is a balanced chemical equation?
A balanced chemical equation can be defined as a chemical equation wherein the number of atoms on the reactant side (left) is equal to the number of atoms on the product side (right).
In this scenario, Sodium azide ([tex]NaN_3[/tex]) undergoes a decomposition reaction due to an electrical impulse, which causes it to produce elemental sodium and nitrogen gas.
The properly balanced chemical equation for this chemical reaction is given by:
[tex]2NaN_3 \rightarrow 2Na + 3N_2[/tex]
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The molecular-orbital model for Ge shows it to be:_______.
A) a conductor, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large.
B) an insulator, because all the lower energy band orbitals are filled and the gap between the lower and higher bands is large.
C) a semiconductor, because the gap between the filled lower and empty higher energy bands is relatively small.
D) a semiconductor, because the gap between the filled lower and empty higher energy bands is large.
E) a conductor, because its lower energy band orbitals are only partially filled.
Answer:
Option C
Explanation:
Pure germanium is a bad conductors of electricity. It is so because its valence band is full and its outer electrons are attached through covalent bond is a diamond like framework. In metallic sense, it is neither a conductor nor an insulator but a semiconductor. It has a small band gap of 0.7eV.
Hence, option C is correct
For most substances the density of a solid form is slightly greater than the density of liquid form water however is different it is slightly less dense in the solid form than it is in liquid form compare water in the solid form with neon argon in oxygen and proposal reason why solid water is less dense liquid water
Answer:
Answer: When water freezes, water molecules form a crystalline structure maintained by hydrogen bonding. Solid water, or ice, is less dense than liquid water. Ice is less dense than water because the orientation of hydrogen bonds causes molecules to push farther apart, which lowers the density.
Explanation:
How are people and the landscape impacted by earthquake?
they are impacted because people loose their home due to the wreckage that has happend and landscapes are ruined due to landslides
Answer:
Well the landscape is torn up, it goes through quite a bit of damage. the plants, animals, and water are all affected by it. when a earth quake hits it destroyes most everything, houses fall into the ground and are destroyed, people die. Earthquakes destry electrical wires and many other things
Explanation:
Sorry I did not answer it full, but you can look it up online.
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DIMENSIONAL ANALYSIS CHEMISTRY SUPER easy MOLE CONVERSIONS!!
Question : How many moles of O2 are in the sample of 3.6 kilograms of air if 21% of the air is oxygen O2 by mass?
Answer:
47.25 moles
Explanation:
First we find the amount of O2 in mass in air
That will be = (21/100) x 3.6
This will give us=0.756 kg
Now we want to find the moles, so we convert this mass into grams since we are going to be working with grams= 0.756 x 1000 = 756 grams
Now, to find the number of moles:
moles= mass / molar mass
in this case mass is 756 grams and molar mass of oxygen is 16
So, the mass divided by molar mass would be =756/16= 47.25 moles of O2
1. What is a forensic palyn ologist?
2. Describe the case that Mildenhall worked on in New Zealand.
3. How can a forensic palynologist help a crime investigation?
4. What are the challenges of using a forensic palynologist in crime investigations?
Answer:
A forensic palynologist is a spore and pollen expert that helps solve crimes.
The case that Mildenhall worked on was about a murder that involved a prostitute. The police couldn’t find a trace to help solve the case, so they called Mildenhall to help with pollen clues. He was able to find trace evidence in the pollen, which helped police connect the victim to a gang hangout by the crime scene.
A forensic palynologist can help with a criminal investigation by comparing pollen from the suspect and the victim using a comparison microscope to determine if the pollen matches.
The challenges of using a forensic palynologist in a criminal investigation are that judges and juries may have a hard time understanding palynologists.
Explanation:
Answers of the following points regarding forensic palynologist are given below:
What is forensic palynology?This is a internal branch of palynology that deals with the relationship among different objects to prove or disprove, which may belongs to both criminal and civil cases.
(1). Forensic palynologist is a person who do the case study of the crime seen, and deals with a spore and pollen.
(2). Mildenhall worked on a murder case in New Zealand where a prostitute was involved. Police were not able to solve the crime, so they called Mildenhall to help with pollen clues. Mildenhall who is a spore and pollen expert was able to study the pollen clues and gave hint to the police as they were do further process to connect with the victim.
(3). A forensic palynologist by comparing the pollen clues from the crime scene and the victim, can help with a criminal investigation by using a comparison microscope to determine if the pollen matches.
(4). As forensic palynology is a science study which can not be general understand by normal people; so that judges, juries and advocates may have a hard time understanding palynologists and this is the challenges of using a forensic palynologist in crime investigations.
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Suppose you want to prepare a buffer with a pH of 4.59 using formic acid. What ratio of [sodium formate]/[formic acid) do you need to make this buffer? Formic acid has a K, of 1.8x10 4 Enter your answer to three significant figures.
Answer:
7.08
Explanation:
To solve this problem we'll use the Henderson-Hasselbach equation:
pH = pka + log[tex]\frac{[A^-]}{[HA]}[/tex]Where [tex]\frac{[A^-]}{[HA]}[/tex] is the ratio of [sodium formate]/[formic acid] and pka is equal to -log(Ka), meaning that:
pka = -log (1.8x10⁻⁴) = 3.74We input the data:
4.59 = 3.74 + log[tex]\frac{[A^-]}{[HA]}[/tex]And solve for [tex]\frac{[A^-]}{[HA]}[/tex]:
0.85 = log[tex]\frac{[A^-]}{[HA]}[/tex][tex]10^{(0.85)}[/tex]=[tex]\frac{[A^-]}{[HA]}[/tex][tex]\frac{[A^-]}{[HA]}[/tex] = 7.08The ratio of [sodium formate] to [formic acid] needed to make the buffer is 7.08
How to determine the pKaEquilibrium constant (Ka) = 1.8×10¯⁴pKa =?pKa = –Log Ka
pKa = –Log 1.8×10¯⁴
pKa = 3.74
How to determine the ratio of [sodium formate] to [formic acid]pH = 4.59pKa = 3.74Ratio of [sodium formate] to [formic acid] =?pH = pKa + Log[sodium formate]/[formic acid]
4.59 = 3.74 + Log[sodium formate]/[formic acid]
Collect like terms
4.59 – 3.74 = Log[sodium formate]/[formic acid]
0.85 = Log[sodium formate]/[formic acid]
Take the anti-log of 0.85
[sodium formate]/[formic acid] = anti-log 0.85
[sodium formate]/[formic acid] = 7.08
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A biochemist prepares a 1 L solution using 12.1 g of Tris Buffer. The final concentration is 0.1 M. What is the MW of Tris Buffer?
Answer: The molecular weight of tris buffer is 121 g/mol
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in L
moles of tris buffer = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{12.1g}{Mg/mol}[/tex]
Now put all the given values in the formula of molality, we get
[tex]0.1=\frac{12.1g}{Mg/mol\times 1L}[/tex]
[tex]M=121g/mol[/tex]
Therefore, the molecular weight of tris buffer is 121 g/mol
A rigid container has 44.5 grams of oxygen gas at room temperature and a pressure of 2.3 atm. How many grams of oxygen should the container have for the pressure to be 7.8 atm?
Answer:
The mass of oxygen the container must have is 150.85 g.
Explanation:
Given;
mass of the oxygen, m₁ = 44.5 g
initial pressure of the gas, P₁ = 2.3 atm
final pressure of the gas, P₂ = 7.8 atm
Atomic mass of oxygen gas, = O₂ = 16 x 2 = 32 g
initial number of moles of oxygen in the container, n₁ = 44.5/32 = 1.39
let the final number of moles of oxygen = n₂
Apply ideal gas equation;
PV = nRT
[tex]\frac{PV}{Rn} = T\\\\since \ temperature\ T \ is \ constant;\\\\\frac{P_1V}{Rn_1} = \frac{P_2V}{Rn_2}\\\\\frac{P_1}{n_1} = \frac{P_2}{n_2} \\\\n_2 = \frac{n_1P_2}{P_1} \\\\n_2 = \frac{1.39 \times 7.8}{2.3} \\\\n_2 = 4.714 \ moles[/tex]
The mass of the oxygen in grams is calculated as;
m₂ = 4.714 x 32g
m₂ = 150.85 g
Therefore, the mass of oxygen the container must have is 150.85 g.
in the photosynthesis the energy starts as ___ energy and ends up as___energy
light heat
chemical: chemical
heat light
light chemical
Answer: Light, Chemical
Explanation: This is the answer because "photosynthesis takes place in two stages: the light-dependent reactions and the Calvin cycle. In the light-dependent reactions, which take place at the thylakoid membrane, chlorophyll absorbs energy from sunlight and then converts it into chemical energy with the use of water." - source https://opentextbc.ca/
In the photosynthesis the energy starts as Light energy and ends up as Chemical Energy. Hence option (D) is correct
What is Photosynthesis ?The process by that inexperienced plants and a few different organisms use daylight to synthesize nutrients from carbonic acid gas and water. chemical action in plants usually involves the inexperienced pigment and generates element as a by-product.
Photosynthesis may be a method employed by plants and different organisms to convert lightweight energy into energy that, through internal respiration, will later be discharged to fuel the organism's activities.
photosynthesis takes place in 2 stages: the light-dependent reactions and also the Calvin cycle. within the light-dependent reactions, that manifest itself at the thylakoid membrane, pigment absorbs energy from daylight and so converts it into energy with the employment of water.
Therefore, In the photosynthesis the energy starts as Light energy and ends up as Chemical Energy. Hence option (D) is correct
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How are stars and comets different?
A star has a solid rock and gas surface, while a comet has tail of dust and gas.
A star has a tail of dust and gas, while a comet has a solid rock surface.
A star is made up of burning gases, while a comet is made up of ice, gases, rocks, and dust.
A star is made up of ice, rocks, and dust, while a comet is made up of burning gases.
Answer:
Explanation:
The main difference between these two is that a star has a solid rock and gas surface, while a comet has tail of dust and gas. A star is a giant mass of rock and gas that follows a set eliptical path. Comets on the other hand are made of ice and dust with some gases and usually travel in a straight path. This is why they have a tail of dust and gas which is the ice burning up behind it as it travels at extremely high speeds.
Answer: A: A star has a solid rock and gas surface, while a comet has tail of dust and gas.
Explanation:
Which of the following is evidence that a chemical
change is occurring?
a. Cherry drink mix is added to water and the resulting
solution is red.
b. A white powder is added to cool tap water in a beaker
and the beaker gets hot.
c. Water is added to coffee until the solution becomes
clear.
d. Water is added to sand and the sand looks darker
Answer:
c. water is added to coffe until the solution becomes clear
Answer:
c
Explanation:
Water is added to coffee until the solution becomes
clear.
does a mole of hydrogen have the same mass as a mole of oxygen? explain your answer
Local winds can be caused by______heating of the earth's surface.
equal
ground
uneven
super
How many moles are in 6.34 x 10^24 molecules of ZnCl2?
Answer:
10.53 moles ZnCl2
Explanation:
Number of atoms in 2.56 moles of He
1.54 × 10²⁴ atoms He
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
MolesAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Stoichiometry
Using Dimensional AnalysisExplanation:Step 1: Define
[Given] 2.56 moles He
[Solve] atoms He
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[DA] Set up: [tex]\displaystyle 2.56 \ mol \ He(\frac{6.022 \cdot 10^{23} \ atoms \ He}{1 \ mol \ He})[/tex][DA] Multiply [Cancel out units]: [tex]\displaystyle 1.54163 \cdot 10^{24} \ atoms \ He[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
1.54163 × 10²⁴ atoms He ≈ 1.54 × 10²⁴ atoms He
How many moles in 2.33E25 molecules of NO?
0.0258 mol
3.87E20 mol
38.7 mol
2.58E48 mol
please show work
Answer:
0.0258 mol Answer .......
In liquids, the attractive intermolecular forces are ________. In liquids, the attractive intermolecular forces are ________. strong enough to keep the molecules confined to vibrating about their fixed lattice points strong enough to hold molecules relatively close together strong enough to hold molecules relatively close together but not strong enough to keep molecules from moving past each other not strong enough to keep molecules from moving past each other
Answer:
strong enough to hold molecules relatively close together but not strong enough to keep molecules from moving past each other.
Explanation:
In liquids, the attractive intermolecular forces are strong enough to hold molecules relatively close together but not strong enough to keep molecules from moving past each other.
Intermolecular forces are the forces of repulsion or attraction.
Intermolecular forces lie between atoms, molecules, or ions. Intramolecular forces are strong in comparison to these forces.
In liquids, the attractive intermolecular forces are strong enough to hold
molecules relatively close together but not strong enough to keep
molecules from moving past each other.
Liquid is a state of matter in which the atoms are relatively close to each
other but less than that of solids which are densely and tightly packed.
The intermolecular force in liquids are strong enough to hold them together
which makes them less easily compressible but not strong enough to keep
them from moving or gliding past each other because they aren't tightly
packed.
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Based on the vibrational difference you observed, state a hypothesis to explain why diatomic molecules in the air, such as oxygen and nitrogen, are not greenhouse gases while those with 3 or more atoms, such as methane, are?
Answer:
See explanation
Explanation:
The ability of a gas to function as a green house gas depends on its ability to absorb infra red rays. In turn, the absorption of infrared red rays depends on whether or not the molecule is IR active.
The triatomic molecules such as methane and water are IR active. Only IR active molecules can lead to green house effect.
Note that for a molecular vibrational mode to be IR active, the dipole moment of the molecule is changed as the vibration occurs .
What is the correct order for the three steps of how a hormone would work
A. Response > Reception > Transduction.
B. Reception > Response > Transduction.
C. Reception > Transduction > Response.
D. Transduction Response > Signaling.
Answer:
answers is -d
Explanation:
,kggc’hnftfj’trudging.ugu,y
Which of these describes a Mole in Chemistry?
A. A counting term for substances
B. The Molar mass of substance in grams
C. 6.02 x 10^23
D. All of the above describe a mole
Answer: Thus the correct option is D. All of the above describe a mole
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass in grams.
1 mole of every substance contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
Mole is the S.I unit for measuring the amount of substance. It is often used to measure large number of particles.
Thus the correct option is D. All of the above describe a mole
What would a student carrying out a titration use a to transfer 25 mL of sodium hydroxide into a conical flask?
a) conical flask
b) burette
c) measuring cylinder
d) pipette
Mixture of water and non-dissolved materials.
A mixture of water and non-dissolved materials is called a heterogeneous mixture.
A heterogeneous mixture is a mixture that contains two or more substances that are not uniformly distributed throughout the mixture.
In a mixture of water and non-dissolved materials, the non-dissolved materials are not uniformly distributed throughout the water. Instead, they will settle to the bottom of the container over time.
Therefore, heterogeneous mixture is a mixture of water and non-dissolved materials.
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Both amines and amides are derivatives of
acetic acid
sodium hydroxide
ammonia
sodium chloride
Answer:
Ammonia
Explanation:
Both amines and amides are structurally similar to ammonia, the difference is the introduction of a carbon into the structure.
AlCl3(s)+Ca3N2(s)→AlN(s)+CaCl2(s)
Answer:
the subject of a talk, piece of writing, exhibition, etc.; a topic.
Explanation:
Answer:
1 NH4NO3(s) → 1 N2(g) + 4 H2O(g) + 2 O2(g)
Explanation:
3. Noble gases are sometimes called "inert gases." What can you infer about the meaning of the word "inert" in chemistry?
Answer:
Noble gases are sometimes called "inert gases." What can you infer about the meaning of the word "inert" in chemistry? It refers to substances that easily lose electrons. It refers to substances that do not react with other substances. It refers to substances that have strong electrochemical charges.
Explanation:
1. How many grams does 10 moles of Carbon weigh?
Answer:120
Explanation: I think
Answer:
1321.177 grams.
Explanation:
each mole of carbon is 12.0107 grams.
How many moles of electrons are required for denitrifying organism to reduce 78 moles of nitrate to dinitrogen gas?
Answer:
780 moles e⁻
Explanation:
N⁺⁵ in NO₃⁻ requires 2(5e⁻) => 1/2 mole N₂(g)
That is, NO₃⁻ + 2(5e⁻/mole N₂ formed) => 1/2N₂
NO₃⁻ + 10e⁻/mole N₂ formed => 1/2N₂
∴ 78 mole NO₃⁻ requires 780 moles e⁻ => 1/2(78) moles N₂ = 39 moles N₂
Denitrification is the reduction of nitrate to dinitrogen gas. It is achieved by denitrifying organism According to stoichiometry, 390 moles of electrons are required to reduce 78 moles of nitrate to dinitrogen gas.
The equation of denitrification;
2 NO3− + 10 e− + 12 H+ → N2 + 6 H2O
From this equation;
2 moles of nitrate requires 10 moles of electrons
78 moles of nitrate requires 78 * 10/2 = 390 moles of electrons
Hence, 390 moles of electrons are required to reduce 78 moles of nitrate to dinitrogen gas.
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help?
A 22.98 g sample of a compound contains 7.33 g of potassium, K, 6.65 g of chlorine, Cl, and oxygen, O. Calculate the empirical formula.
Insert subscripts as needed.
Empirical formula: KClO
Answer:
[tex]KClO_3[/tex]
Explanation:
Hello!
In this case, as we know the mass of the total sample, we can first compute the mass of oxygen:
[tex]m_O=22.9g-7.33g-6.65g=8.92g[/tex]
Next, we compute the moles of each element:
[tex]n_K=\frac{7.33g}{39.9g/mol}= 0.184mol\\\\n_{Cl}=\frac{6.65g}{35.45g/mol}=0.188mol \\\\n_O=\frac{8.92g}{16.00g/mol} =0.5575mol[/tex]
Now, we divide the moles by 0.184 moles, the fewest ones, to obtain:
[tex]K=\frac{0.184}{0.184}=1.0 \\\\Cl=\frac{0.187}{0.184}=1.0\\\\O=\frac{0.5575}{0.184} =3.0[/tex]
Therefore, the empirical formula is:
[tex]KClO_3[/tex]
Regards!