Ans :4.5 * 10²³ molecules
Given:
Moles of CH4 = 0.75
To determine;
The number of molecules of CH4 in 0.75 moles
Explanation:
1 mole of CH4 contains Avogadro's number i.e. 6.023*10²³ molecules
Therefore, 0.75 moles would correspond to :
= 0.75 moles * 6.023*10²³ molecules/1 mole
= 4.5 * 10²³ molecules
Answer:
4.5
Explanation:
Which of the following is the best defense against all germs?
cleanliness
vaccination
antibiotics
isolation
Answer:
The best defense against all germs would be vaccination.
Vaccines are specifically designed to stimulate the immune system to recognize and defend against specific pathogens (bacteria, viruses, etc.). They are a highly effective way to prevent many infectious diseases and provide immunity against a wide range of germs. Vaccination helps protect individuals and can also contribute to herd immunity, reducing the spread of diseases within communities.
Cleanliness is essential for preventing the spread of germs but may not protect against all germs, as some are highly contagious or can survive in various environments. Antibiotics are effective against bacterial infections but do not work against viruses or other pathogens. Isolation can help prevent the spread of germs in certain situations, but it is not a comprehensive defense against all germs, and it may not be practical or necessary in many cases.
a chemical reaction produces .884 mols of H2S gas. what volume will the gas occupy at STP? Knowing the molar mass is 32.0 g/mol, what is the density of this gas?
explain how cells, proteins, deoxyribonucleic acid (DNA) molecules, chromosomes, and genes are related to each other.
***50 POINTS***
Which of the following combinations will result in a reaction that is only spontaneous at low temperatures?
A) positive enthalpy change and positive entropy change
B) positive enthalpy change and negative entropy change
C) negative enthalpy change and positive entropy change
D) negative enthalpy change and negative entropy change
I think it's C, or maybe D, please help!
The correct answer is D)negative enthalpy change and negative entropy change
Given the data, the correct statement is negative enthalpy change and negative entropy change (Option D)
Gibbs free energyΔG = ΔH – TΔS
Where
ΔG is the Gibbs free energy ΔH is the enthalpy changeT is the temperature ΔS is the change in entropyNOTE
ΔG = +ve (non spontaneous) ΔG = 0 (equilibrium) ΔG = –ve (spontaneous)Since the reaction is at low temperature, then TΔS must be smaller than ΔH
Thus, ΔH and ΔS must be negative for the reaction to be spontaneous as illustrated below:
ΔH = -ve (greater)ΔS = -veΔG =?ΔG = ΔH – TΔS
ΔG = (-ve) – T(-ve)
ΔG = (-ve) – T(-ve)
ΔG = –ve
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____ indicate a bal of .10 % or higher
Intoxication with most people, attention and control are impaired, slow reflexes, thinking and coordination are slowed, and driving skills are extremely impaired
At STP, which sample contains the same number of molecules as 3.0 liters of H2(g)?
A) 1.5 L of NH3(g)
B) 2.0 L of CO2(g)
C) 3.0 L of CH4(g)
D) 6.0 L of N2(g)
Answer is: C) 3.0 L of CH4(g).
Vm = 22.4 L/mol; molar volume at STP (Standard Temperature and Pressure).
At STP one mole of gas occupies 22.4 liters of volume.
In this question all substances are gases, amount of substance depends on volume of the gas.
Same volume, same number of molecules.
So 3 liters of hydrogen gas (H₂) has the same number of molecules as 3 liters of methane gas (CH₄).
Which type of element seeks to lose electrons
A circuit is shown in the picture above. Energy is transferred first from the battery to the circuit wire and then from the circuit wire to the light. What energy transformations occur between these two transfers? A. Energy is transformed first from chemical energy to light and heat energy and then from light and heat energy to electrical energy. B. Energy is transformed first from mechanical energy to chemical energy and then from chemical energy to light and heat energy. C. Energy is transformed first from chemical energy to mechanical energy and then from mechanical energy to light and heat energy. D. Energy is transformed first from chemical energy to electrical energy and then from electrical energy to light and heat energy.
D? I'm aware that I'm late
Sorry but the answer may be right
Specific heat capacity of a substance is the amount of heat required to raise the temperature by one degree Celsius of one gram of a substance. Therefore, the correct option is option D that is energy is transformed first from chemical energy to electrical energy and then from electrical energy to light and heat energy.
What is Enthalpy?Enthalpy term is basically used in thermodynamics to show the overall energy that a matter have. Mathematically, Enthalpy is directly proportional to specific heat capacity of a substances.
Energy is transferred first from the battery to the circuit wire and then from the circuit wire to the light. Here, energy is transformed first from chemical energy to electrical energy and then from electrical energy to light and heat energy.
Therefore, the correct option is option D.
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PLEASE HELP! 50 POINTS IF CORRECT!
Choose which diagram best represents season changes on Earth caused by the relationship between the Earth and Sun.
When placed near each other, opposite magnetic poles repel each other. Please select the best answer from the choices provided T F
Answer: The correct answer is False.
Explanation:
A magnet has two poles defined as a north pole and a south pole.
When two same poles come closer to each other, they tend to repel each other and when two opposite poles come closer to each other, they tend to attract each other.
So, when north pole comes near to another north pole, they will repel each other while when north pole comes near to the south pole, they attract each other.
Hence, the above statement is False.
compare chemical weathering to mechanical weathering
Chemical weathering and mechanical weathering are two types of weathering processes that break down rocks through different mechanisms. Chemical weathering involves chemical reactions, while mechanical weathering involves physical forces. Both types of weathering can occur simultaneously and work together.
Explanation:Chemical weathering and mechanical weathering are two types of weathering processes that break down rocks, but they involve different mechanisms. Chemical weathering occurs when rocks are broken down through chemical reactions, such as oxidation or dissolution. Mechanical weathering, on the other hand, involves physical forces, such as ice wedging, abrasion, or root growth, that break rocks into smaller pieces.
An example of chemical weathering is the rusting of iron, where iron reacts with oxygen in the presence of moisture to form iron oxide. An example of mechanical weathering is the freeze-thaw cycle, where water seeps into cracks in rocks, freezes, expands, and causes the rocks to break apart.
Both types of weathering can occur simultaneously and contribute to the overall weathering process. They can also work together, as in the case of tree roots growing into cracks in rocks and exerting physical force while also releasing acids that chemically break down the rocks.
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What is the experimental molar heat of combustion
the molecules if DNA produced in replication are
Answer:
They Are Connected
how many significant figures are in the measurement 0.0020100 kilograms
In order for oxygen gas, nitrogen gas, and carbon dioxide to have the same volume, they must have the same ______. (Check all answers that are true. There may be one or more than one.) Question 1 options:
1.temperature 2.pressure 3. mass 4.number of molecules 5. formula
which of the following statements about DNA of gametes is true?
B) Gametes result in new combinations of genes and have one half of the DNA of somatic cells.
Because gametes are formed through a type of cell division called meiosis.
Meiosis results in cells with half the number of chromosomes as the parent cell. Since DNA is organized into chromosomes, gametes end up with half the DNA content of somatic cells.
Additionally, meiosis shuffles and recombines genetic material, creating new combinations of genes in the gametes. This contributes to genetic diversity in offspring.
Which of the following was not included in the bill of rights
Answer:
voting rights
Explanation:
There is nothing specifically written in the Bill of Rights regarding voting rights.
4. In a chemical reaction, mass is conserved. This means that (1 Point)
a) The mass of the reactants stays the same during a chemical reaction
b) The mass of the products stays the same during a chemical reaction
c) The type and number of atoms in the reactants equals the type and number of atoms in the products
d) The mass of the products is always twice the mass of the reactants.
In a chemical reaction, the number of atoms that remained conserved is the same in the products and the reactants. Thus, option C is correct.
The law of conservation of mass states that during the chemical reaction the mass has not been lost, it has been converted from one form to another.
The law of conservation states that the mass of the reactant and products have been similar in a chemical reaction. The mass has been expressed in terms of the number of atoms for each type of atom.
Thus, in a chemical reaction, the number of atoms that remained conserved is the same in the products and the reactants. Thus, option C is correct.
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WILL GIVE BRAINLIEST! Which of the following most likely caused the formation of stars and planets?
Asteroids
Comets
Force of gravity
Oxygen and water
Answer:
Force of gravity
Explanation:
What organisms get their energy from eating other things
The higher u hold something above the ground?
A. They prevent viral infections.
B. They break down complex molecules.
C. They provide nutrients.
D. They do not.
How can you tell if two objects are in thermal equilibrium?
A. The objects are touching each other.
B. The object's temperatures are changing.
C. The object's are the same size.
D. The object's have the same temperature.
What is it called when energy transfers between objects until they reach the same temperature and their particles move at the same rate? Kinetic Energy Thermal energy Thermal equilibrium Movement
Answer:The correct answer is option Thermal equilibrium.
Explanation:
Thermal equilibrium: When the two objects with with difference in temperature comes in contact with each other. Object with higher temperature transfer its heat to the an object with lower temperature.This transfer will last until the temperature of both the objects becomes equal.
At this point objects are said to be in Thermal equilibrium.
P = ? in kPa
V= 0.602 L
n = 0.00801 mol
T = 311 K
R = 8.314 L-kPa/mol-K
Use numbers as written to calculate. Round to nearest hundredth.
solutions of sodium fluoride and dilute hydrochloric acid are mixed
how much heat is required to convert 74 grams of ice at -4 C into 74 grams of water at 52 C
Hf=334 j/g
To convert 74 grams of ice at -4°C into 74 grams of water at 52°C, we need to calculate the heat required for temperature change and phase change. First, we heat the ice from -4°C to 0°C, then calculate the heat required to convert the ice at 0°C to water at 0°C, and finally heat the water from 0°C to 52°C. The total heat required is 41341.36 J.
Explanation:To calculate the heat required to convert 74 grams of ice at -4°C into 74 grams of water at 52°C, we need to consider the temperature change and the phase change. First, we need to heat the ice from -4°C to its melting point of 0°C. The heat required can be calculated using the equation Q = mCpΔT, where Q is the heat, m is the mass, Cp is the specific heat capacity and ΔT is the change in temperature.
Q = 74 g x 2.06 J/g°C x (0°C - (-4°C)) = 607.04 J
Next, we need to calculate the heat required to convert the ice at 0°C into water at 0°C. This is the heat of fusion, which is 334 J/g. Therefore, the heat required is given by:
Q = 74 g x 334 J/g = 24716 J
Lastly, we need to heat the water from 0°C to 52°C. Using the same equation as before:
Q = 74 g x 4.18 J/g°C x (52°C - 0°C) = 16018.32 J
To find the total heat required, we sum up the heat calculated above: 607.04 J + 24716 J + 16018.32 J = 41341.36 J.
Two descriptions for a sub-atomic particle are listed below: Description 1: Non-charged particle Description 2: Located inside the nucleus of an atom Which sub-atomic particle or particles fit these descriptions? Electrons only Neutrons only Electrons and protons Protons and neutrons
Description 2: Located inside the nucleus of an atom fits neutrons only.
Electrons are not located inside the nucleus of an atom. They are found in electron orbitals or electron clouds surrounding the nucleus. Therefore, Description 2 does not apply to electrons.
Protons are positively charged particles located inside the nucleus of an atom. However, Description 1 states "Non-charged particle," which does not fit protons since protons are positively charged.
Neutrons are particles located inside the nucleus of an atom, and they are electrically neutral, meaning they have no net charge. Therefore, Description 2 fits neutrons.
Electrons are negatively charged particles located outside the nucleus of an atom. Description 1, "Non-charged particle," does not apply to electrons.
So, based on the descriptions provided:
Description 1 does not fit any of the sub-atomic particles listed.
Description 2 fits neutrons only, as they are located inside the nucleus of an atom and are non-charged particles.
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The Culpepper basin in Virginia, as well as some smaller basins near Richmond, have many rocks filled with fish fossils and dinosaur tracks. These rocks are MOST LIKELY A) igneous. B) intrusive. C) sedimentary. D) metamorphic.
Answer:
c- Sedimentary
Explanation:
The movement of food substances from the stems to growing tissues and storage tissues is called:
please!
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Hydrogen and oxygen bond together due to the number of electrons in their orbitals. So it would be labeled two hydrogen and one oxygen.