Answer:
A well tested explanation of a natural phenomenon
Explanation:
A scientific theory is an explanation of a natural phenomenon which has been drawn from a well tested observation.
Theories are products of repeated scientific experiments. When a hypothesis otherwise known as a "scientific guess" survives a lot of scrutiny, we can elevate it to the status of a theory. Most theories starts off from simple observations. These observations can further spark series of experiments in such a field and a scientific guess proposed. Further testing and experimenting would now lead to a theory.
What are two ways selective breeding is helpful in agriculture
Answer:
1: it can produce crops that are resistant to pest
2: it can result in animals that can produce more food
Explanation:
i had the same question
Absolute zero is
the freezing point of water using the Celsius scale
the freezing point of liquid nitrogen
the temperature on the Kelvin scale corresponding to 32 °F
the coldest temperature possible
the boiling point of liquid nitrogen
Absolute zero is the lowest possible temperature and is the temperature at which all molecular motion ceases. It is measured on the Kelvin scale, where water freezes at 273 K and boils at 373 K.
Explanation:Absolute zero is the lowest possible temperature and is the temperature at which all molecular motion ceases.
It is measured on the Kelvin scale, where water freezes at 273 K and boils at 373 K, with 0 K being absolute zero.
This temperature is significant in scientific work and is used in fields such as astronomy
Final answer:
Absolute zero is the theoretical temperature at which molecular motion stops, corresponding to 0 K, -273.15°C, or -459.67°F. It is the starting point of the Kelvin scale. The Celsius scale, more common in daily usage, has water's freezing point at 0°C and boiling point at 100°C.
Explanation:
Absolute zero is defined as the coldest possible temperature, a theoretical limit where all molecular motion ceases. This temperature corresponds to 0 Kelvin (K) on the Kelvin temperature scale and is equivalent to approximately -273.15 degrees Celsius (°C) and -459.67 degrees Fahrenheit (°F). The Kelvin scale is an absolute temperature scale used primarily in the sciences.
The Celsius scale is another temperature scale which is used widely around the world. On this scale, the freezing point of water is 0°C and the boiling point is 100°C at standard atmospheric pressure. This scale is more commonly used in daily life, but in scientific contexts, especially when dealing with thermodynamic temperature, the Kelvin scale is preferred because it starts from this absolute zero point.
To convert from Celsius to Kelvin, one simply adds 273.15 to the Celsius temperature. This is because the size of one unit on both the Celsius and Kelvin scales is the same; the only difference is their starting points (0°C is equivalent to 273.15K).
3. Which is true about the combustion of carbon?
O Carbon is produced from oxygen and carbon dioxide.
The reaction is spontaneous.
O Enthalpy remains constant.
Entropy decreases.
The combustion of carbon is a spontaneous process where carbon reacts with oxygen to form carbon dioxide. During this process, the enthalpy of the system decreases and the entropy increases.
Explanation:The combustion of carbon, a chemical reaction involving carbon and oxygen, primarily results in the formation of carbon dioxide. This process is spontaneous under standard conditions, which means that it occurs naturally without needing any additional input. However, the statement that carbon is produced from oxygen and carbon dioxide is incorrect; rather, carbon and oxygen react to form carbon dioxide in a combustion reaction.
From the thermodynamic perspective, the enthalpy of the system decreases as heat is released during the combustion, so it's not true that enthalpy remains constant. This is an exothermic reaction, which involved a negative change in enthalpy. The entropy, or the degree of randomness or disorder, increases due to the production of gas molecules from a single carbon atom and oxygen molecule, contrary to the claim that the entropy decreases.
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If a certain compound has a formula H2X . What is the Valency of X ?
Answer:
2
Explanation:
The valency of an atom is the number of H atoms to which it can bond.
An atom of X can bond to two H atoms, so the valency of X is 2.
How many moles are there in 4.00 g of ethanol, CH 3CH 2OH?
Answer:
there are 0.087 moles of ethanol in a 4.00 G sample of ethanol
Explanation:
Number of moles present in a substance is equal to the mass divided by molar mass.
Mathematically, No. of moles = [tex]\frac{mass}{\text{molar mass}}[/tex]
As it is given that mass is 4.00 g and molar mass of [tex]CH_{3}CH_{2}OH[/tex] is 46.07 g/mol.
Hence, calculate the number of moles of [tex]CH_{3}CH_{2}OH[/tex] as follows.
No. of moles = [tex]\frac{mass}{\text{molar mass}}[/tex]
= [tex]\frac{4.0 g}{46.07 g/mol}[/tex]
= 0.086 mol
Thus, we can conclude that number of moles of [tex]CH_{3}CH_{2}OH[/tex] present in 4.00 g is 0.086 mol.
An element has two isotopes. One has a mass of 5.03 amu and an abundance of 25%, the other has a mass of 7.20 amu and an
abundance of 75%. What is the average atomic mass of the element?
Answer:
Average atomic mass = 6.6575.
Explanation:
As fractions the abundance is 1/4 and 3/4.
The average atomic mass = (5.03 + 3(7.20) / 4
= 6.6575.
Which statement is true according to the kinetic theory?
A. Molecules of different gases with the same mass and temperature always have the same average density
B. Molecules of different gases with the same mass and temperature always have the same average volume
C. Molecules of different gases with the same mass and temperature always have the same pressure.
D. Molecules of different gases with the same mass and temperature always have the same molecular mass
E. Molecules of different gases with the same mass and temperature always have the same average kinetic energy
Answer:
Molecules of different gases with the same mass and temperature always have the same average kinetic energy - E.
Answer:
Molecules of different gases with the same mass and temperature always have the same average kinetic energy.
A sample of neon has a volume of 40.81 m3 at 23.5C. At what temperature, in Kelvins, would the gas occupy 50.00 cubic meters? Assume pressure is constant.
At [tex]\fbox{\begin \\363 K \end{minispace}}[/tex] temperature, a sample of neon gas will occupy [tex]50.00 \text{ m}^{3}[/tex] volume.
Further Explanation:
The given problem is based on the concept of Charles’ law. Charles’ law states that “at constant pressure and fixed mass the volume occupied an ideal gas is directly proportional to the Kelvin temperature.”
Mathematically the law can be expressed as,
[tex]\fbox{ \begin \\ V \propto T \end{minispace}}[/tex]
Or,
[tex]\frac{V}{T}=k[/tex]
Here, V is the volume of the gas, T is Kelvin temperature, and k is proportionality constant.
Given information:
The initial volume of neon gas is [tex]40.81 \text{ m}^{3}[/tex] .
The final volume of neon gas is [tex]50.00 \text{ m}^{3}[/tex].
The initial temperature value is [tex]23.5 \text{ } ^{\circ} \text{C}[/tex] .
To calculate:
The final temperature
Given Condition:
The pressure is constant.Mass of gas is fixed.Solution:
Step 1: Modify the mathematical expression for Charles’ law for two different temperature and volume values as follows:
[tex]\frac{V_{1}}{T_{1}}=\frac{V_{2}}{T_{2}}[/tex]
Here,
[tex]V_{1}[/tex]is the initial volume of the gas.[tex]V_{2}[/tex] is the final volume of the gas.[tex]T_{1}[/tex] is the initial temperature of the gas.[tex]T_{2}[/tex] is the final temperature of the gas.Step 2: Rearrange equation (2) for .
[tex]\fbox {\begin \\T_{2}=\frac{(V_{2}) \times (T_{1})}{V_{1}}\\\end{minispace}}[/tex] …… (2)
Step 3: Convert the given temperature from degree Celsius to Kelvin.
The conversion factor to convert degree Celsius to Kelvin is,
[tex]T(\text{K}) = T(^{\circ}\text{C}) + 273.15[/tex] …… (3)
Substitute [tex]23.5\text{ }^{\circ} \text{C}[/tex] for [tex]T(^{\circ}\text{C})[/tex] in equation (3) to convert temperature from degree Celsius to Kelvin.
[tex]T(\text{K}) = 23.5 \text{ } ^{\circ} \text{C} + 273.15\\T(\text{K})= 296.65 \text{ K}[/tex]
Step 4: Substitute [tex]40.81 \text{ m}^{3}[/tex] for [tex]V_{1}[/tex] , [tex]50.00 \text{ m}^{3}[/tex] for [tex]V_{2}[/tex] and [tex]296.65 \text{ K}[/tex] for [tex]T_{1}[/tex] in equation (2) and calculate the value of [tex]T_{2}[/tex] .
[tex]T_{2}=\frac{(50.00 \text{ m}^{3}) \times (296.65 \text{ K})}{40.81 \text{ m}^{3}}\\T_{2}=363.45 \text{ K}\\T_{2} \approx 363 \text{ K}[/tex]
Important note:
The temperature must be in Kelvin.The condition of fixed mass and fixed pressure must be fulfilled in order to apply Charles’ law.Learn More:
1. Gas laws https://brainly.com/question/1403211
2. Application of Charles’ law https://brainly.com/question/7434588
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: States of matter
Keywords: neon, volume, occupies, temperature, Kelvin, degree Celsius, Charle’s law, constant pressure, fixed mass, 40.81 m^3 , 50.00 m^3 , 23.5 degree C , celsius , 363 K , sates of matter, initial volume, final volume, initial temperature, final temperature, V1 , V2 , T1 , T2 .
At 363.27 degrees temperature, in Kelvins, the gas occupies 50.00 cubic meters.
What is Charles' Law?Charles' law (also known as the law of volumes) is an experimental gas law that describes how gases tend to expand when heated.
To calculate the final temperature of the system, we use the equation given by Charles' Law. This law states that the volume of the gas is directly proportional to the temperature of the gas at constant pressure.
Mathematically,
[tex]\frac{V_1}{T_1} = \frac{V_2}{T_2}[/tex]
where,
[tex]V_1[/tex] and [tex]T_1[/tex] are the initial volume and temperature of the gas.
[tex]V_1[/tex]and [tex]T_2[/tex] are the final volume and temperature of the gas.
Apply Charles' Law which states that the volume of a gas at constant pressure is directly proportional to the Kelvin temperature.
23.5 C = 273 + 23.5 = 296.5 degrees K.
40.81 / 296.5 = 50 ÷ x where x is the required temperature.
x = 363.27 degrees.
Hence, At 363.27 degrees temperature, in Kelvins, the gas occupies 50.00 cubic meters.
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A brick has a mass of 4.0kg and the earth has a mass of 6.0*10^27g.
what is the mass of 1 mole of bricks?
how many moles of bricks have a mass equal to the mass of the earth?
Answer:
[tex]\boxed{\text{6.022 $\times 10^{23}$ kg; 2.5 $\times 10^{-4}$\ mol}}[/tex]
Explanation:
1. Mass of 1 mol of bricks
[tex]m = 6.022 \times 10^{23}\text{ bricks} \times \dfrac{\text{4.0 kg}}{\text{ 1 brick}} = 2.4 \times 10^{24}\text{ kg}\\\\\text{The mass of 1 mol of bricks is }\boxed{\textbf{2.4 $\times\mathbf{10^{24}}$ kg}}[/tex]
2. Number of moles
(a) Convert grams to kilograms
[tex]6.0 \times 10^{24}\text{ g} = 6.0 \times 10^{21}\text{ kg}[/tex]
(b) Convert kilograms to moles
[tex]n = 6.0 \times 10^{21}\text{ kg} \times \dfrac{\text{1 mol bricks }}{2.4 \times 10^{24}\text{ kg}} = \text{0.0025 mol bricks}\\\\\text{The mass of the Earth equals the mass of }\boxed{\textbf{0.0025 mol of bricks}}[/tex]
Answer: The mass of 1 mole of brick is [tex]24.088\times 10^{26}g[/tex] and the moles of brick having same mass as earth is 2.49 moles.
Explanation:
We are given:
Mass of a brick = 4.00 kg = 4000 g (Conversion factor: 1 kg = 1000 g)
According to mole concept:
[tex]6.022\time 10^{23}[/tex] number of atoms are contained in 1 mole of an atom.
As, mass of 1 brick is 4000 g
So, mass of [tex]6.022\times 10^{23}[/tex] number of bricks will have = [tex]\frac{4000}{1}\times 6.022\times 10^{23}=24.088\times 10^{26}g[/tex]
Now, calculating the moles of brick having the mass equal to the mass of Earth.
Mass of Earth = [tex]6\times 10^{27}g[/tex]
To calculate the moles of bricks, we apply unitary method, we get:
[tex]24.088\times 10^{26}g[/tex] of mass is occupied by 1 mole of brick
So, [tex]6.0\times 10^{27}g[/tex] of mass will be occupied by [tex]\frac{1}{24.088\times 10^{26}}\times 6.0\times 10^{27}=2.49moles[/tex]
Hence, the mass of 1 mole of brick is [tex]24.088\times 10^{26}g[/tex] and the moles of brick having same mass as earth is 2.49 moles.
What would cause the shape of a molecule to be tetrahedral?
A. Three atoms bound to a central atom with one lone pair
B. Four atoms bound to a central atom with two lone pairs
C. Four atoms bound to a central atom with no lone pairs
D. Two atoms bound to a central atom with two lone pairs
Answer:
A molecule is tetrahedral if the central atom has four bonds and no lone pairs. Explanation: ... The electron pairs in the bonds repel the electrons in the other bonds, so they all try to get as far from each other as possible.
According to the molecular geometry,four atoms bound to a central atom with no lone pairs would cause the shape of a molecule to be tetrahedral.
What is molecular geometry?
Molecular geometry can be defined as a three -dimensional arrangement of atoms which constitute the molecule.It includes parameters like bond length,bond angle and torsional angles.
It influences many properties of molecules like reactivity,polarity color,magnetism .The molecular geometry can be determined by various spectroscopic methods and diffraction methods , some of which are infrared,microwave and Raman spectroscopy.
They provide information about geometry by taking into considerations the vibrational and rotational absorbance of a substance.Neutron and electron diffraction techniques provide information about the distance between nuclei and electron density.
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Write 126.7 g in scientific notation
The expression of 126.7 g in scientific notation results in 1.267 x 10^-1 kg.
To write 126.7 g in scientific notation, we need to convert it to kilograms. Since the base unit of mass in the SI system is the kilogram, we can express 126.7 g as 1.267 × 10-1 kg in scientific notation. Therefore, 126.7 g in scientific notation is 1.267 × 10-1 kg.
which organelles surround the cell?check all that apply
a) cell wall
b) cell membrane
c) nucleus
d) endoplasmic reticulum
e) ribosome
Answer:
cell walls
Explanation:
because the rigid structure that surrounds the cell membrane and provides support to the cells
Answer:
A. Cell wall
B. Cell membrane
Hope this Helps!
What is agovado constant
Chemistry help please
Answer:
The reaction isn't yet at equilibrium. The overall reaction will continue to move in the direction of the products.
Assumption: this system is currently at [tex]\rm 900^{\circ}C[/tex].
Explanation:
One way to tell whether a system is at its equilibrium is to compare its reaction quotient [tex]Q[/tex] with the equilibrium constant [tex]K_c[/tex] of the reaction.
The equation for [tex]Q[/tex] is quite similar to that for [tex]K_c[/tex]. The difference between the two is that [tex]K_c[/tex] requires equilibrium concentrations, while [tex]Q[/tex] can be calculated even when the system is on its way to equilibrium.
For this reaction,
[tex]\displaystyle Q = \rm \frac{[CS_2]\cdot [H_2]^{4}}{[CH_4]\cdot [H_2S]^{2}}[/tex].
Given these concentrations,
[tex]\displaystyle Q = \rm \frac{[CS_2]\cdot [H_2]^{4}}{[CH_4]\cdot [H_2S]^{2}} =\frac{1.51\times (1.08)^{4}}{1.15\times (1.20)^{2}} \approx 1.72[/tex].
The question states that at [tex]\rm 900^{\circ}C[/tex], [tex]K_c = 3.59[/tex]. Assume that currently this system is also at [tex]\rm 900^{\circ}C[/tex]. (The two temperatures need to be the same since the value of [tex]K_c[/tex] depends on the temperature.)
It turns out that [tex]Q = K_c[/tex]. What does this mean?
First, the system isn't at equilibrium.Second, if there's no external changes, the system will continue to move towards the equilibrium. Temperature might change. However, eventually [tex]Q[/tex] will be equal to [tex]K_c[/tex], and the system will achieve equilibrium.In which direction will the system move? At this moment, [tex]Q < K_c[/tex]. As time proceeds, the value of [tex]Q[/tex] will increase so that it could become equal to [tex]K_c[/tex]. Recall that [tex]Q[/tex] is fraction.
[tex]\displaystyle Q = \rm \frac{[CS_2]\cdot [H_2]^{4}}{[CH_4]\cdot [H_2S]^{2}}[/tex]
When the value of [tex]Q[/tex] increases, either its numerator becomes larger or its denominator becomes smaller, or both will happen at the same time. However,
Concentrations on the numerator of [tex]Q[/tex] are those of the products; Concentrations on the denominator of [tex]Q[/tex] are those of the reactants.As time proceeds,
the concentration of the products will increase, while the concentration of the reactants will decrease.In other words, the equilibrium will move towards the products.
What category do you think humans fall into?
Animal obviously
It could be carnivore, herbivore or omnivore
Which of the following is an exothermic reaction?
A) melting ice
B) iron rusting
C) dissolving sugar in water
D) dissolving ammonium nitrate in water
The exothermic reaction among the choices is B. iron rusting. An exothermic reaction is a reaction that releases heat. Rust is formed from the reaction of iron with oxygen. This reaction releases heat, hence, an exothermic reaction.
Further Explanation:
A. melting ice is an endothermic process. An endothermic process requires the absorption of energy from the surroundings. Heat is needed to change ice to liquid water. That is why, when ice is removed from the freezer and left on a warmer place it melts. The heat from the surroundings is absorbed by the ice causing it to change to liquid phase.
B. iron rusting is exothermic. Heat is released when oxygen and iron react to form rust.
C. dissolving sugar in water is an endothermic process. Heat is needed to break up the intermolecular forces of attraction holding the sugar molecules together. Also, adding heat makes the process of dissolution faster
D. dissolving ammonium nitrate in water is an endothermic process. A characteristic of endothermic reactions is that it turns the container of a substance colder. As the substance absorbs heat from the surroundings, the temperature of the surroundings, including the container, decreases. In exothermic reactions, heat is released to the surroundings making the container feel hotter during and after the reaction.
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As the number of solute particles in a solution increases, the effect on the freezing point of the solution increases. Which ionic compound will lower the freezing point the most if 1 mol of it is added to 1 L of water?
NaCl
MgCl2
KBr
AlCl3
Answer:
AlCl₃.
Explanation:
Adding solute to water causes depression of the boiling point.
The depression in freezing point (ΔTf) can be calculated using the relation:
ΔTf = i.Kf.m,
where, ΔTf is the depression in freezing point.
i is the van 't Hoff factor.
van 't Hoff factor is the ratio between the actual concentration of particles produced when the substance is dissolved and the concentration of a substance as calculated from its mass. For most non-electrolytes dissolved in water, the van 't Hoff factor is essentially 1.
Kf is the molal depression constant of water.
m is the molality of the solution (m = 1.0 m, for all solutions).
(1) NaCl:
i for NaCl = no. of particles produced when the substance is dissolved/no. of original particle = 2/1 = 2.
∴ ΔTb for (NaCl) = i.Kb.m = (2)(Kf)(1.0 m) = 2(Kf).
(2) MgCl₂:
i for MgCl₂ = no. of particles produced when the substance is dissolved/no. of original particle = 3/1 = 3.
∴ ΔTb for (MgCl₂) = i.Kb.m = (3)(Kf)(1.0 m) = 3(Kf).
(3) NaCl:
i for KBr = no. of particles produced when the substance is dissolved/no. of original particle = 2/1 = 2.
∴ ΔTb for (KBr) = i.Kb.m = (2)(Kf)(1.0 m) = 2(Kf).
(4) AlCl₃:
i for AlCl₃ = no. of particles produced when the substance is dissolved/no. of original particle = 4/1 = 4.
∴ ΔTb for (CoCl₃) = i.Kb.m = (4)(Kf)(1.0 m) = 4(Kf).
So, the ionic compound will lower the freezing point the most is: AlCl₃.
Answer: AlCl₃. :) de nada
How are the wavelength and frequency of a wave related?
metuency increases wavelength increases
requency increases wavelength decreases
wavelength remains constant as frequency changes
wavelength and frequency are not related
Answer:
frequency increases as wavelength decrease.
Explanation:
frequency = velocity/wavelength
Answer:
Frequncy increases, wavelength decreases
Explanation:
A wave can be defined as the repetitive pattern of a travelling energy. Waves can also be defined as a disturbance from equilibrium (or rest) of a medium which oscillates along a stable region. Examples of waves include: seismic waves, gravitational waves, shock waves, heat waves, sound waves etc
In a standing wave (ie at different points of the wave, amplitude is constant), its properties are:
Amplitude which is the the distance of the disturbance from equilibrium. It can also be defined as the distance between the highest point of the wave(peak or crest) to the lowest point (trough).
Wavelength(lambda) is the distance between one peak to the next peak or one trough to another trough parallel to the direction of propagation.
Frequency, f is the number of times a wave passes a particular point per unit time.
Wave velocity is the speed at which disturbance moves. It can given as an equation:
V = f*(lambda)
It can also be written as:
f = V/(lambda)
From the relationship above,
We can see that an increase in frequency of the wave would lead to a decrease in its wavelength and vice versa.
For the reaction below, describe the temperature and pressure conditions that would produce the highest yield for the forward reaction. Explain your answer in terms of Le Châtelier’s principle.
CO (g) + 2 H2 (g) Two arrows stacked on top of each other. The top arrow points to the right. The bottom arrow points to the left. CH3OH (g) deltaH = -90.7 kJ/mol
Answer:
Explanation:
The complete reaction equation is given as:
CO + 2H₂ ⇄ CH₃OH ΔH = -90.7kJmol⁻¹
From the reaction equation, we know that:
the reactants are in gaseous phases. Carbon monoxide(CO) and Hydrogen gas are gases. the reaction is an exothermic reaction beceause ΔH is negative. Heat would be liberated to the surroundings in this kind of reaction.According to Le Chatelier's principle, we know that "if any of the conditions of a system in equilibrium is changed, the system will adjust itself in order to annul the effect of the change".
For pressure changes:
A change in pressure affects only equilibrium involving a gas or gases. An increase in pressure will shift the position of equilibrium to the side having smaller volume(or mole) and vice versa.
CO + 2H₂ ⇄ CH₃OH
3 moles of gases 1 mole of gas
An increase in pressure will favor the production of more methanol since we have 3 moles of gas on the left hand side and just one mole of gas on the right hand side.
For temperature changes:
A rise in temperature shifts equilibrium to the direction that absorbs heat and vice versa. Since the reaction is exothermic in the forward reaction, a rise in temperature will favor the forward reaction. This would lead to the production of more methanol gas. A decrease in temperature will favor the backward reaction.
What is the specific latent heat of fusion of ice if it takes 863 kJ to convert 4.6 kg of ice into water at 0 C?
Answer:
39698
Explanation:
Mass= 4.6kg
latent heat= 863
ML= 4.6*863= 39698
approximately = 397 In three significant figures
Answer : The specific latent heat of fusion of ice is, 187.608 J/g
Explanation :
Formula used :
[tex]Q=m\times L_f[/tex]
where,
Q = heat supply = 863 KJ = 863000 J
conversion used : (1 KJ = 1000 J)
m = mass of the substance = 4.6 Kg = 4600 g
conversion used : (1 Kg = 1000 g)
[tex]L_f[/tex] = specific latent heat of fusion = ?
Now put all the given values in the above formula, we get the specific latent heat of fusion of ice.
[tex]863000J=4600g\times L_f[/tex]
[tex]L_f=187.608J/g[/tex]
Therefore, the specific latent heat of fusion of ice is, 187.608 J/g
What is the final pressure (expressed in atm) of a 3.05 l system initially at 724 mm hg and 298 k, that is compressed to a final volume of 2.60 l at 273
Answer:
P2 = 778.05 mm Hg = 1.02 atm
Explanation:
We are to find the final pressure (expressed in atm) of a 3.05 liter system initially at 724 mm hg and 298 K which is compressed to a final volume of 2.60 liter at 273 K.
For this, we would use the equation:
[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]
where P1 = 724 mm hg
V1 = 3.05 L
T1 = 298 K
P2 = ?
V2 = 2.6 L
T2 = 173 K
Substituting the given values in the equation to get:
[tex]\frac{(724)(3.05)}{298} =\frac{P_2(2.6)}{173}[/tex]
P2 = 778.05 mm Hg = 1.02 atm
For real gases, how does a change in pressure affect the ratio of PVto nRT?
A. The ratio increases as pressure increases.
B. The ratio is constant at all pressures.
C. The ratio decreases as pressure increases.
Answer:
B. The ratio is constant at all pressures.Explanation:
You can deduce the ratio of PV to nRT from the ideal gas equation.
Ideal gas equation: PV = nRT⇒ PV / nRT = 1.
Thus the ratio PV to nRT is constant and equal to 1, at all pressures, such as the statement B describes.
Hence, if P increases or decreases, the other variables, V, n, or T must change to keep the ration constant and equal to 1. R is the universal constant.
Answer:
The correct answer option is A. the ratio increases as the pressure increases.
Explanation:
We are to determine whether which of the given answer options explains how does a change in pressure affect the ration of PV to nRT.
We know that, for real gases:
[tex]PV = nRT[/tex]
where,
[tex] P [/tex] is the pressure of the gas ,
[tex] V [/tex] is the volume of gas ,
[tex] n [/tex] is the number of moles ,
[tex] R [/tex] is the gas constant; and
[tex] T [/tex] is the temperature of the gas.
Gay-Lussac’s law states that for a constant volume, the pressure of that gas is directly proportional to the temperature on the Kelvin scale.
Therefore, the ratio increases as the pressure increases.
The nucleus of an atom consists of
A. Protons ans neutrons
B. Neutrons alone
C. Protons and electrons
D. Neutrons and electrons
Answer:
The nucleus of an atom consists of Protons and Neutrons.-A.
Which feature is common to prokaryotic and eukaryotic cells?
cell nuclei
complex structures
organelles
cell membranes
Answer:
Cell membranes
Explanation:
Cell membranes is a feature that is common to prokaryotic and eukaryotic cells.
Answer:cell membranes
Explanation:
what type of intermolecular force occurs between polar molecules?
A) dipole-dipole force
B) hydrogen bonding
C) induced dipole force
D) polar covalent bonding
Answer:
A) dipole-dipole force
Explanation:
A dipole-dipole force is the type of intermolecular force that occurs between polar molecules.
The intermolecular force occurs between polar molecules is dipole-dipole bonding. The correct option is A)
What are intermolecular force?Intermolecular forces are those forces that occur when two atom, molecules or ions come close together. There are different types of intermolecular force present between different molecules.
Thus, the correct option is A) dipole-dipole force
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Percent Composition Calculations
The Mole
What is the percent of Hin
NH3?
(H = 1.008 amu, N = 14.01 amu)
[?]%
Answer:
[tex]\boxed{\text{17.76 \% by mass}}[/tex]
Explanation:
[tex]\text{The mass of one molecule of NH$_{3}$ is:}\\\text{14.01 u N + 3.024 u H = 17.034 u}\\\\\text{mass $\%$ H} =\dfrac{3.024}{17.034} \times 100 \%} =\textbf{17.76 \%}\\\\\text{Ammonia contains }\boxed{\textbf{17.76 \% H by mass}}[/tex]
If it requires 35.0 milliliters of 0.50 molar NaOH to neutralize 25.0 milliliters of HCl, what is the concentration of the HCl solution? (3 points)
Balanced equation: NaOH + HCl yields NaCl + H2O
0.36 M HCl
0.70 M HCl
1.1 M HCl
1.4 M HCl
Answer:
0.7M
Explanation:
Volume of NaOH = 35mL = 0.035L
Concentration of NaOH = 0.5M
Volume of HCl = 25mL = 0.025L
Concentration of HCl = ?
Solution;
The balanced equation of the reaction is shown below:
NaOH + HCl → NaCl + H₂O
To solve this problem, we solve from the known to the unknow. The known here is the parameters of NaOH. From here, we can find the number of moles;
Number of moles of NaOH = concentration x volume= 0.035 x 0.5
= 0.0175mole
From the balanced reaction equation, we can state that:
1 mole of NaOH reacted with 1 mole of HCl
0.0175mole of NaOH will reacted with 0.0175mole of HCl
Now that we know the number of moles of the acid used, we can calculate the concentration of the acid used using the expression below:
Concentration of acid = [tex]\frac{number of moles of acid}{volume of acid}[/tex]
Concentration of acid= [tex]\frac{0.0175}{0.025}[/tex] = 0.7M
In both physical and chemical changes,
a. energy can be gained or lost.
b. matter is created
c. matter is destroyed
d. Both a and b
rite your answers on the lines below.
Answer:
option a. energy can be gained or lost.Explanation:
Energy can be gained or lost in both physical and chemical changes.
Most physical changes involve energy gain or loss. For example:
Melting: for a substance to change from solid to liquid, the substance has to gain energy to increase the kinetic energy of the particles and they can overcome the forces of attraction and separate.Similar reasoning can be made about freezing, evaporation, condensation, and many other physical changes.
As per chemical changes, in order to the reactant substances break their bonds energy must be gained, and as new bonds are formed to constitute the product substaces energy is loss. The net change of energy will tell if the reaction is endothermic (net gain of energy) or exothermic (net release or loss of energy).
In order to meet the energy conservation law, the energy that is gained or lost by a substance is lost or gained by other substance.
As per the options b. and c. the law of conservation of mass states that energy can be never be created or destroyed, so those options are incorrect.
why do densities of haloalkanes decrease when the size of alkyl group increases?
when the alkyl grp increases, the van der waals force between polar molecules becomes stronger, so shouldnt the molecules pack closer to each other and the density increase?
Answer:
Here's what I get.
Explanation:
Your argument makes sense. For example, the density of C₅H₁₂ is about 0.63 g/mL, and it increases gradually to a limit of about 0.83 g/mL.
With the lower alkyl halides, the halogen atom is the major contributor to the mass of the molecule. The density of chloromethane is 2.2 g/mL.
As you increase the number of C atoms, the Cl atom becomes a smaller part of the molecule. The alkyl halide becomes more like an alkane.
By the time you have reached four C atoms, the density has reached a limiting value of about 0.89 g/mL.
The melting point of an ionic compound will increase as which of the following increases
Answer:
Charge of the ions and size of the ions
Explanation:
Answer:
Lattice Energy
Explanation:
Melting point is the temperature at which a solid changes into a liquid.
The process is called as Melting.
Lattice energy is the energy required by an ionic compound in order to overcome the electrostatic force which is existing between the oppositely charged ions.
Ionic compound which has a strong electrostatic force will have high melting point .
Energy required to break the ionic bond or the Lattice array is more.
Lattice energy depends on two main factors
1) charge of the ions and
2) size of the ions
Lattice energy increases with the increase in charge.
For example Lattice energy of MgO is larger than NaCl.
Mg and O have 2+ and 2- charges respectively
Na and Cl have 1+ and 1- charges.
Lattice energy increases with decrease in size of the ions.
For example NaCl Lattice energy is larger than KBr.
[tex]Na^+[/tex] is smaller than [tex]K^+[/tex] ion
[tex]Cl^-[/tex] is smaller than [tex]Br^-[/tex]