Answer:
When a mixture of water and alcohol boils, the vapors are a mixture of water vapor and alcohol vapor
chemistry class 9 chapter 1
Explanation:
i) Melting point = 15°C and Boiling point = 110°C
ii) The region C on graph there is only liquid state, the region A on graph there is only solid state.
iii) The straight line A1 - B1 shows that the melting point of solid wax and getting converted to liquid form.
iv) Latent heat of vaporization is a physical property of a substance.
It is defined as the heat required to change one mole of liquid at its boiling point under standard atmospheric pressure.
v) At 'B' the wax is at both solid and liquid state
An empirical research method in which data are gathered from observations of phenomena, hypothesis are formulated and tested, and conclusions are drawn that validate or modify the original hypothesis is known as the: Group of answer choices Gotham theory Scientific Method Niels-Bohr hypothesis Entropy theory
Answer:
Scientific Method
Explanation:
Science is empirical in nature. The entire purpose of science is to discover new knowledge.
The empirical research method in science all begins with gathering observations from phenomena. After that, the researcher formulates appropriate hypothesis which are rigorously tested.
The conclusions drawn from testing the original hypothesis validate or modify the original hypothesis.
What is the most common isotope for element X
Answer:
isotope 2
Explanation:
it has the highest percentage abundance
PLS HELP!!
Compare and contrast an electrolytic cell with a voltaic cell. Provide one example where both are present in daily life.
Answer:
See explanation
Explanation:
An electrolytic cell functions by a non spontaneous chemical process. Energy is supplied in the form of electricity through a battery to drive the electrochemical process.
A voltaic cell functions by a spontaneous chemical process. Energy or work can be derived from a voltaic cell.
When iron is rusting, a natural voltaic cell is set and the iron is converted to hydrated iron III hydroxide. The set up used for the extraction of sodium metal from brine functions on the basis of electrolysis.
Which of the following is a base? (3 points)
AgO
Ca(OH)2
HF
NaCl
Answer:
Ca(OH)2 is base
is answer of this question
hope this will help you more
Answer:
Ca(OH)2
Explanation:
Got it right on the test
What is octyne?
O A. An alkane
B. An alkyne
C. A polymer
D. An alkene
SUBMIT
Answer:
B. An alkyne
Explanation:
Octynes are alkynes with one triple bond
what is chemical reaction?
Answer:
a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.
Or
Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products. ... A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.
Below are descriptions of different center voids of a solid fuel. Which design
shape will generate the most thrust?
A. A heart
OB. A circle
C. A triangle
O D. A tree with branches
B. A circle.
The center void shape that generates the most thrust in a solid fuel rocket is a circle.
What is Fuel?
Fuel is a substance that is used to produce heat or energy through combustion or other chemical reactions. It can be in the form of a solid, liquid, or gas and is typically used to power engines, generators, or heating systems. Examples of fuels include gasoline, diesel, natural gas, coal, wood, and propane. The choice of fuel depends on factors such as availability, cost, energy content, and environmental impact.
This is because a circular shape allows for the most efficient burning of the fuel, with the flame front moving evenly in all directions. Other shapes, such as a heart, triangle, or tree with branches, can cause uneven burning and may result in less thrust.
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Answer:
Explanation:
D.
tree with branches
The ground state of an electron is the least stable energy state of an atom
Answer:
electron configuration
Explanation:
The arrangement of electrons in the atomic orbitals of an atom is called the electron configuration. Electron configurations can be determined using a periodic table.
Why are measurements important for science?
Pleaseee help me :( give two reasons why it's important
Answer:
measurements are important to do calculations to get correct results and without them scientists cannot form theories
1. A) Calculate DO of water at 25 0 C, P 0 = 1.01x10 5 Pa; given: water vapor pressure (25 0 C) is 3.2x10 3 Pa and Henry constant of oxygen in water is 1.3x10 -8 mol/l.Pa b) How's DO content changed as increase or decrease water temperature? Explain.
Answer:
cfvgbhnjmk,
Explanation:
aseous methane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 5.5 g of methane is mixed with 13.9 g of oxygen. Calculate the maximum mass of carbon dioxide that could be produced by the chemical reaction. Round your answer to significant digits.
Answer:
There is 9.6 grams of CO2 produced
Explanation:
Step 1: Data given
Mass of methane = 5.50 grams
Molar mass of methane = 16.04 g/mol
Mass of oxygen = 13.9 grams
Molar mass of oxygen = 32.0 g/mol
Step 2: The reaction
CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
Step 3: Calculate number of moles
Moles = mass / molar mass
Moles methane = 5.50 grams / 16.04 g/mol
Moles methane = 0.343 moles
Moles oxygen = 13.9 grams / 32.0 g/mol
Moles oxygen = 0.434 moles
For 1 mol CH4 we need 2 moles O2 to produce 1 mol CO2 and 2 moles H2O
O2 is the limiting reactant. It will completely react (0.434 moles).
There will react 0.434/2 = 0.217 moles CH4
There will remain 0.343-0.217 = 0.126 moles CH4
There will be produced 0.434 moles of H2O and
0.434/2 =0.217 moles of CO2
Step 4: Calculate mass of products
Mass = moles * molar mass
Mass CO2 = 0.217 moles ¨44.01 g/mol
Mass CO2 = 9.6 grams
Mass H2O = 0.434 moles * 18.02
Mass H2O = 7.8 grams
If 1000. mL of water freezes, which of the following is a reasonable approximation for the volume of the resulting ice?
Group of answer choices
1000. mL
961 mL
1040 mL
No answer text provided.
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Answer:
If 1000. mL of water freezes, which of the following is a reasonable approximation for the volume of the resulting ice?
Group of answer choices
1000. mL
961 mL
1040 mL
Explanation:
Ice is fewer denser than water.
The reason is the volume occupied by the same mass of ice with water is more than the volume occupied by water. Ice has more empty space within it.
Due to this reason, ice floats on water.
When 1000ml of water freezes to ice then its volume is greater than water.
Among the given options the correct answer is 1040 mL .
The combustion of gasoline produces carbon dioxide and water. Assume gasoline to be pure octane (C8H18) and calculate the mass (in kg) of carbon dioxide that is added to the atmosphere per 1.0 kg of octane burned
Answer:
3.1 kg
Explanation:
Step 1: Write the balanced combustion equation
C₈H₁₈ + 12.5 O₂ ⇒ 8 CO₂ + 9 H₂O
Step 2: Calculate the moles corresponding to 1.0 kg of C₈H₁₈.
The molar mass of C₈H₁₈ is 114.23 g/mol.
1.0 × 10³ g × 1 mol/114.23 g = 8.8 mol
Step 3: Calculate the moles of CO₂ produced from 8.8 moles of C₈H₁₈
The molar ratio of C₈H₁₈ to CO₂ is 1:8. The moles of CO₂ produced are 8/1 × 8.8 mol = 70 mol.
Step 4: Calculate the mass corresponding to 70 moles of CO₂
The molar mass of CO₂ is 44.01 g/mol.
70 mol × 44.01 g/mol = 3.1 × 10³ g = 3.1 kg
Consider this equilibrium:
HCO3- + H2PO4-HPO42- + H2CO3.
What are the Brønsted-Lowry acids in this equilibrium?
A. HCO3- and H2CO3
B. HCO3 and HPO42-
C. H2PO4! and H2CO3
D. H2PO4' and HPO4-
E. HCO3 and H2PO4!-
Answer:
the answer is option E they are bronsted lowry acid
In electrolysis of sodium chloride, hydrogen and chlorine are liberated from the aqueous sodium chloride solution. Both the gases are transferred into a container which is maintained at 4 atm and 30 ℃. Calculate the volume of the container if 100 mol of H2 and 100 mol of Cl2 are transferred
Answer:
1.2 × 10³ L
Explanation:
Step 1: Calculate the total number of gaseous moles
n = nH₂ + nCl₂ = 100 mol + 100 mol = 200 mol
Step 2: Convert 30 °C to Kelvin
We will use the following expression.
K = °C + 273.15 = 30 + 273.15 = 303 K
Step 3: Calculate the volume of the container
We will use the ideal gas equation.
P × V = n × R × T
V = n × R × T / P
V = 200 mol × (0.0821 atm.L/mol.K) × 303 K / 4 atm = 1.2 × 10³ L
In which of the following will the density increase?
Group of answer choices
An iron bar is heated.
A lead weight is moved from sea level to the top of a high mountain.
A sample of water is frozen.
A diamond is submerged in water.
A sample of chlorine gas is compressed.
Not sure how to answer this:
A. Identify the side that is acidic
B. Explain why it's acidic
C. Identify the side that is basic
D. Explain why this side is basic
Answer:
A. The red side is acidic.
B. Because it has more positive hydrogen ions.
C. The blue side is basic.
D. Because it has more negative hydroxide ion.
Given the data from the question,
A. The side with more H⁺ is acidic
B. It is acidic because it contains more H⁺
C. The side with more OH¯ is basic
B. It is basic because it contains more OH¯
What is pH ?This is simply a measure of the acidity / alkalinity of a solution.
The pH measures the hydrogen ion concentration while the pOH measures the hydroxide ion concentration
pH scaleThe pH scale is a scale that gives an understanding of the variation of the acidity / alkalinity of a solution.
The scale ranges from 0 to 14 indicating:
0 to 6 indicates acid 7 indicates neutral 8 to 14 indicate basicHow to determine which side is acidic.The presence of H⁺ indicates acidity.
Thus, the side with more H⁺ is acidic.
How to determine which side is basicThe presence of OH¯ indicates the solution is basic.
Therefore, the side with more OH¯ is basic
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El simbolo del ion que contiene 24 protones, 28 neutrones y 21 electrones es : A)Sc+3 B)Sc-3 C)Sc D)Cr E)Cr-3
Answer:
Cr ^ 3 +
Explanation:
Recordemos que el número atómico es el número de protones en el núcleo del átomo. También corresponde al número de electrones en el átomo neutro.
Dado que el número de protones es 24, entonces el elemento debe ser cromo.
Si hay 21 electrones presentes, entonces se deben haber perdido 3 electrones para dar Cr ^ 3 +.
Which idea behind the shape of molecules includes the concept that electrostatic repulsion between electron pairs surrounding an atom causes these pairs to be separated as far as possible
Answer:
VSEPR theory
Explanation:
The valence shell electron pair repulsion theory was propounded by Gillespie and Nylom (1957).
The entire idea of the VSEPR theory is that the shape of a molecule depends on the electrostatic repulsion between electron pairs surrounding the central atom in a molecule which causes these pairs to be separated as far as possible.
The shapes of many molecules can be accurately predicted based on this model.
How is each nucleotide different from the others?
A. It has different bases.
B. It has different side chains.
C. It has different carboxyl groups.
D. It has different amine groups.
Answer:
a. po tamang sagot
Explanation:
pa pafoolow po pleasr
The DNA and RNA are polynucleotides which contain a chain of nucleotides monomers with different nitrogenous bases. Each nucleotide different from the others, as It has different bases. The correct option is A.
What is a nucleotide?A nucleotide is defined as a compound containing three component units, namely a pentose sugar (either ribose or 2-deoxyribose), a heterocyclic nitrogenous base (a substituted purine or a substituted pyrimidine) and a phosphate group.
The nucleotides are the phosphate esters of nucleosides. A nucleotide containing ribose as the sugar unit is termed as the ribonucleotide. While one containing 2-deoxyribose as the sugar unit is termed as the deoxyribonucleotide.
The nitrogenous bases in RNA are adenine, guanine, cytosine and uracil whereas in DNA the bases are adenine, guanine, cytosine and thymine. The purines are adenine and guanine whereas cytosine, thymine and uracil are pyrimidines.
Thus the correct option is A.
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what is the difference between physical chemistry and environmental chemistry.
please Answer and give the correct answer...
Answer:
Physical chemistry is the study of macroscopic, and particulate phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics, analytical dynamics and chemical equilibrium while environmental chemistry is the study of chemical processes that occur in water, air, terrestrial and living environments, and the effects of human activity on them.
Physical chemistry is the area of chemistry that deals with how materials interact and change. The scientific study of chemical and biological phenomena that take place in the environment is known as environmental chemistry.
Physical chemistry attempts to quantify, correlate, and explain the quantitative features of reactions by focusing, in contrast to other branches, on the physics principles that underlie all chemical interactions (such as the gas laws).
While environmental chemistry is the study of chemical species' sources, reactions, movement, impacts, and fates in the air, soil, and water environments, as well as the impact of human activity and biological activity on these, can be summed up as the field of chemical ecology.
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Which natural law do biogeochemical cycles address?
help me please give two example in which physical change take place please help me
Answer:
Boiling, melting
Explanation:
Physical changes affect the form of a chemical substance.
Ginger wanted to see how long it would take to get to Brownsville from Houston. If it is 570 kilometers (km) to Brownsville, how long would it take her if she could only drive an average speed of 60 km/hour
Answer:
9.5 hours/ 9 hours 30 mins
Explanation:
Distance = speed × time so
Time = Distance ÷ speed
= 570 ÷ 60
= 9.5 hours
A gas has a pressure of 450 mmHg at 100 degrees Celsius. What will its new pressure be when the temperature rises 200 degrees Celsius
Answer:
P2 = 900 mmHg.
Explanation:
Given the following data;
Initial pressure = 450 mmHg
Initial temperature = 100°C
Final temperature = 200°C
To find the final pressure, we would use Gay Lussac's law;
Gay Lussac states that when the volume of an ideal gas is kept constant, the pressure of the gas is directly proportional to the absolute temperature of the gas.
Mathematically, Gay Lussac's law is given by;
[tex] PT = K[/tex]
[tex] \frac{P1}{T1} = \frac{P2}{T2}[/tex]
Making P2 as the subject formula, we have;
[tex] P_{2}= \frac{P1}{T1} * T_{2}[/tex]
[tex] P_{2}= \frac{450}{100} * 200 [/tex]
[tex] P_{2}= 4.5 * 200 [/tex]
Final pressure, P2 = 900 mmHg.
During an experiment, solid iodine was placed in a sealed container. The container was gradually heated and purple-colored vapors of iodine formed were observed. Describe this system when it reaches phase equilibrium. (10 points)
Answer:
See explanation
Explanation:
For a chemical system in a state of dynamic equilibrium, the rate of forward reaction is equal to the rate of reverse reaction.
For this system under consideration;
I2(s)⇄I2(g)
When we heat the container, solid iodine is converted into purple coloured iodine vapour.
When equilibrium is achieved in the system, there will be no net change in the amount of solid iodine and iodine vapour present in the system since the rate of forward and reverse reactions are equal for a system in a state of equilibrium.
A piece of solid tin is submerged in silver nitrate solution. A reaction occurs producing tin (iv) nitrate solution and solid silver. Write the word equation, write the skeletal equation and balanced chemical equation for the reaction.
Answer: For the given reaction-
The word equation is Tin + silver nitrate = tin (IV) nitrate + silverThe skeletal equation is [tex]Sn + AgNO_{3} \rightarrow N_{4}O_{12}Sn + Ag[/tex]The balanced chemical equation is [tex]Sn(s) + 4AgNO_{3}(aq) \rightarrow N_{4}O_{12}Sn(aq) + 4Ag(s)[/tex]Explanation:
When names of chemicals or species involved in a chemical reaction are represented in the form of an equation then it is known as a word equation.For example, Tin + silver nitrate = tin (IV) nitrate + silver
The 'equal to' symbol denotes a forward arrow.
A skeletal equation contains only the chemical formula of species involved in a chemical reaction.For example, [tex]Sn + AgNO_{3} \rightarrow N_{4}O_{12}Sn + Ag[/tex]
A chemical equation which contains same number of atoms on both reactant and product side along with states of species is called a balanced chemical equation.[tex]Sn(s) + 4AgNO_{3}(aq) \rightarrow N_{4}O_{12}Sn(aq) + 4Ag(s)[/tex]
why are metal containers not used for storing acids
Metal containers are not used for storing acid because most of the time acid reacts with almost every metal and produces salts or oxides which alters the acid characteristics making it useless....
a) the use of heat energy to react carbon dioxide with water to produce oxygen. b) a chemical reaction between carbohydrates and oxygen to produce carbon dioxide, water, and heat energy. c) a photochemical reaction involving carbon dioxide and water to produce carbohydrates and oxygen. d) a photochemical reaction involving carbon dioxide and oxygen to produce water and oxygen.
Answer: b) a chemical reaction between carbohydrates and oxygen to produce carbon dioxide, water, and heat energy
Explanation:
Based on the options, I assume that this is talking about the process of respiration. Respiration allows living things to produce energy by reacting carbohydrates with oxygen.
This results in the release of energy in the form of heat in a cell and also the formation of carbon dioxide and water. This type of respiration is known as Aerobic respiration.