Answer:
0.0286 mol Cl
Explanation:
to convert atoms to moles, we need Avogadro's number.
1 mol= 6.02 x 10^23 atoms
1.72 x 10^22 atoms (1 mol/ 6.02 x 10^23)= 0.0286 moles
A plastic wading pool has a circumference of 12.56 feet. Which procedure will help you
find the diameter of the pool?
The diameter of the pool is 4
Explanation:
To calculate the diameter we must write the values given in the question, here
The circumference of the pool is given as C=12.56 feet.
To calculate the diameter of the pool,
If radius is given, Multiply the radius by 2
If Circumference is given divide the circumference by Pi (π)
the constant value for Pi (π)=3.14
Diameter(D)= C/π
12.56/3.14
=4
The diameter for the plastic wading pool is 4
which question would most likely be studied by a physicist
Answer:
how does gravity affect something
Explanation:
they study physics.
hope this helped
In comparing two reactions, the reaction with the greater activation energy always has (A) the slower rate. (B) the faster rate. (C) the rate that varies less with temperature. (D) the rate that varies more with temperature.
Answer: D the rate that varies more with temperature
Explanation: reaction with greater activation energy is not feasible ordinarily as the reacting molecules have little or no energy to overcome the activation energy. But as the temperature of the reaction is increased, the reacting molecules gains more energy to overcome the energy barriers(activation energy) hence proceeding to form products. In this case, the rate of the reaction depends on the temperature. So an increase in temperature will increase the kinetic energy of the molecules thereby increasing the rate of the reaction and a decrease in temperature will leads to a decrease in the rate of the reaction.
Final answer:
In comparing two chemical reactions, the reaction with the greater activation energy typically has the slower rate. This is due to fewer molecules being able to overcome the higher energy barrier to react. The correct answer to the question is (A) the slower rate.
Explanation:
In comparing two reactions, if one has a greater activation energy, it generally has the slower rate. Activation energy is the energy required to initiate a reaction, and it plays a critical role in determining the rate of a chemical reaction. A higher activation energy means that fewer molecules possess the necessary energy to overcome the barrier and react at a given temperature. Thus, the reaction with a higher Ea will have a slower rate.
Therefore, the correct answer to the question is: (A) the slower rate. As temperature increases, reactions with high activation energies can speed up considerably, because the proportion of molecules with sufficient energy to overcome the Ea increases significantly. Conversely, reactions with lower activation energies are less sensitive to temperature changes since a high proportion of molecules already have enough energy, even at lower temperatures.
How does one recognize a periodic trend on the periodic table?
Answer:
Look for predictable changes and patterns - Apex
Answer:
Look for predictable changes and patterns
Explanation:
Ap3x
“While electroplating is most commonly viewed as a finishing process for metals, it can be used with great success on non-conductive material as well”. Justify this statement with suitable examples.
Answer:
ls most commonly viewed as a metals
Caproic acid, which is responsible for the foul odor of dirty socks, is composed of Carbon, Hydrogen, and Oxygen atoms. A sample taken from a pair of abandon socks found in the locker room after a football game yielded 0.0930g of Carbon, 0.0156g of Hydrogen, and 0.0413g of Oxygen. Eww. They must have been worn more than once before being washed. Find the EMPIRICAL formula of caproic acid.
The empirical formula of caproic acid is C3H6O.
Explanation:The empirical formula of caproic acid can be determined by calculating the molar ratios of carbon, hydrogen, and oxygen in the compound. The masses of each element in the sample can be used to calculate the number of moles. From the molar ratios, we can determine the simplest whole number ratio of elements, which gives us the empirical formula.
Given that the sample contains 0.0930g of Carbon, 0.0156g of Hydrogen, and 0.0413g of Oxygen, we can calculate the number of moles:
Carbon: 0.0930g / 12.01 g/mol = 0.007749molesHydrogen: 0.0156g / 1.008 g/mol = 0.01547molesOxygen: 0.0413g / 16.00 g/mol = 0.002583molesNext, we divide the number of moles for each element by the smallest number of moles to get the simplest whole number ratio. In this case, the smallest number of moles is 0.002583moles:
Carbon: 0.007749moles / 0.002583moles = 3Hydrogen: 0.01547moles / 0.002583moles = 6Oxygen: 0.002583moles / 0.002583moles = 1Therefore, the empirical formula of caproic acid is C3H6O.
Final answer:
After converting the given masses of C, H, and O to moles and finding their mole ratio, we determine that the empirical formula for caproic acid is C3H6O.
Explanation:
To determine the empirical formula of caproic acid from the given masses of Carbon (C), Hydrogen (H), and Oxygen (O), we must first convert the masses to moles:
Carbon: 0.0930 g C × (1 mol C / 12.01 g C) = 0.007744 mol C
Hydrogen: 0.0156 g H × (1 mol H / 1.008 g H) = 0.015476 mol H
Oxygen: 0.0413 g O × (1 mol O / 16.00 g O) = 0.002581 mol O
Next, we find the ratio of moles of each element by dividing each by the smallest number of moles.
C: 0.007744 mol / 0.002581 mol = 3
H: 0.015476 mol / 0.002581 mol = 6
O: 0.002581 mol / 0.002581 mol = 1
Thus, the mole ratio of Carbon, Hydrogen, and Oxygen in caproic acid is 3:6:1, which simplifies to 1:2:1/3. However, we cannot have a fraction in an empirical formula, so we multiply by 3 to get whole numbers.
The empirical formula is therefore represented as C3H6O with the assumption that the molecule has the smallest number integers for carbon, hydrogen, and oxygen that maintain the ratio.
calculate "de Broglie" wavelength for each of the following, and use your numerical answers the to explain why macroscopic (large) objects are not ordinarily discussed in terms of their "wave-like" properties. a. an electron moving at .90 times the speed of light.
b. a 150-g ball moving at a speed of 10.m/s
Answer:
a. [tex]2.69 pm[/tex]
b. [tex]4.42\cdot 10^{-34} m[/tex]
Explanation:
The de Broglie wavelength can be found by the following equation:
[tex]\lambda_{dB} = \frac{h}{mv}[/tex]
Here:
[tex]\lambda_{dB}[/tex] is the de Broglie wavelength (in m);
[tex]h[/tex] is the Planck's constant, [tex]h = 6.626\cdot 10^{-34} J\cdot s[/tex];
[tex]m[/tex] is mass (in kg);
[tex]v[tex] is velocity (in m/s).
a. We need to know the mass of an electron here:
[tex]m_e=9.11\cdot10^{-31} kg[/tex]
And the speed of light:
[tex]c = 3.00\cdot 10^8 m/s[/tex]
The fraction of the speed of light is:
[tex]\omega = 0.90[/tex]
Substituting into the equation:
[tex]\lambda_{dB} = \frac{h}{\omega c m_e}=\frac{6.626\cdot10^{-34} J\cdot s}{0.90\cdot 9.11\cdot 10^{-31} kg\cdot 3.00\cdot 10^8 m/s} = 2.69\cdot 10^{-12} m = 2.69 pm[/tex]
b. Similarly, here we have:
[tex]m_b=150 g = 0.150 kg[/tex]
And the velocity of:
[tex]v = 10 m/s[/tex]
We obtain:
[tex]\lambda_{dB}={6.626\cdot 10^{-34} J\cdot s}{0.150 kg\cdot 10 m/s} = 4.42\cdot 10^{-34} m[/tex]
Notice that the wavelength of a large object is smaller by a fraction of:
[tex]\frac{2.69\cdot 10^{-12} m}{4.42\cdot 10^{-34} m} = 6\cdot 10^{21}[/tex]
This means the de Broglie wavelength of a macroscopic object is negligible compared to the wavelength of a microscopic object.
Take a shiny soup spoon and look at your reflection in the side that holds the soup. What does it look like? Can you explain this, using the terms "angle of incidence" and "angle of reflection"? Now turn the spoon over and look at your reflection in the back of it. What does it look like now?
Answer:
When observing the image inside a spoon, the image seems to be bent or cut, because the rays of light deviate with a certain angle of incidence, since they travel slower when passing from the air, where there are less particles, to the liquid, where there are more particles .
When turning the spoon a specular reflection is observed, it is when the surfaces are polished, the light rays are reflected with and angle of reflection in only one direction and in an orderly manner. This is why images are formed that look like copies of objects.
Explanation:
Reflection and refraction of waves are two phenomena that occur when a wave that propagates in a certain medium meets a separation surface with another medium.
Reflection is the change in direction that a wave experiences when it comes into contact with the surface that separates two media while returning to the point where it originated. Refraction is the change of direction and speed that a wave undergoes obliquely on a surface that separates two media with different refractive indices.
Reflection occurs when light hits a surface and part of it changes direction and returns in the same direction to the point from which it left. This phenomenon also occurs with sound waves. Refraction occurs when the invisible light passes through a transparent material, changes direction and passes obliquely between two media with different refractive index. In reflection light travels in the same medium. In refraction, light travels from one medium to another.
Looking at your reflection in a shiny soup spoon is a result of light reflection. The angle of incidence and angle of reflection are equal, resulting in an upright and undistorted image. The back of the spoon is concave, causing an upside down and distorted reflection.
Explanation:
When you look at your reflection in the side of a shiny soup spoon, you will see an upright and undistorted image. This is because of the reflection of light. The angle at which light hits the spoon, known as the angle of incidence, is equal to the angle at which it reflects off the spoon, known as the angle of reflection. The back of the spoon is concave, so when you look at your reflection in it, the image will be upside down and distorted.
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how do valence electrons relate to the chemical reactions of an element?
Answer:
Explanation:
Valance electrons are loosely held electrons of an atom. They are involve in chemical reaction. Consider the example of metals such as group two metals. All these have two valance electrons. They needed six electrons to complete the octet or loses two valance electrons to get complete octet. Thus its easier to remove two electrons than getting six electrons. These metals remove two electrons and form cations.
Now consider the example of nonmetals such group sixteen. They needed two electrons to get complete octet or remove six electrons to get complete octet. Thus its easier for them to get two electrons and they form anion. When group two metals cation and group sixteen anions combine they form compound and chemical reaction occur.
Group two metals also combine with halogens. Two halogens atoms combine with one alkaline earth metal atom to cancel the charge and make compound neutral.
They react with oxygen and form oxide.
2Ba + O₂ → 2BaO
2Mg + O₂ → 2MgO
2Ca + O₂ → 2CaO
Oxygen carry -2 charge while Ca, Mg and Ba +2 and make the compound neutral because charges are equal in magnitude.
With sulfur,
Mg + S → MgS
Ca + S → CaS
Ba + S → BaS
Sulfer carry -2 charge while Ca, Mg and Ba +2 and make the compound neutral because charges are equal in magnitude.
Two people must have the same speed and velocity if
Answer:
They are jogging side by side at 5 m/s
Let's distinguish between the concepts of speed and velocity:
speed is a scalar quantity: a scalar quantity has a magnitude but not a direction, it's simply a number which doesn't indicate the direction of movement;velocity is a vector: a vector indicates both a magnitude (it has a scalar quantity) and a direction.The first condition we have here is the fact that two people have the same speed, this means they are moving at the same rate of change of distance. The second condition must be met as well, if we wish them to have the same velocity, this means they should be moving in the same direction, let's say, along the positive or negative x-axis, but not in opposite directions.
Which of the following pairs of elements is most likely to form a covalent bond? A. Sodium and chlorine B. Magnesium and Oxygen C. Phosphorus and Bromine D. Copper and Oxygen
The pair of elements Phosphorus and Bromine is most likely to form a covalent bond. Covalent bonds typically occur between nonmetals, as they share electrons to reach stability. Other given pairs, involving metals and nonmetals, are more likely to form ionic bonds.
Explanation:Among the pairs of elements provided, the pair that is most likely to form a covalent bond is Phosphorus and Bromine. A covalent bond typically forms when two nonmetals, like phosphorus and bromine, share electrons. In contrast, sodium and magnesium are metals which usually form ionic bonds when they combine with nonmetals (like chlorine for sodium and oxygen for magnesium). Copper can also form ionic bonds with nonmetals like oxygen.
As an example, consider a molecule like oxygen gas (O=O). Each oxygen atom has six electrons in its valence shell and needs two more to reach stability. This stability is achieved when the two oxygen atoms share two pairs of electrons, forming a double covalent bond.
In contrast, consider the formation of sodium chloride (table salt). Sodium readily donates its single valence electron to chlorine, which needs only one more electron to be stable. This results in the formation of a sodium cation and a chloride anion, which are held together by an ionic bond.
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Q10.An aqueous solution contains 5.00x10-2 mol/L of Ca2+ and 7.00x10-3 mol/L of SO4
2-
. Show whether
this solution would precipitate anhydrite CaSO4 or not provided that the Ksp for anhydrite is equal to 10-4.5.
Answer:
The precipitate will form.
Explanation:
Let's write the equilibrium expression for the solubility product of calcium sulfate:
[tex]CaSO_4(s)[/tex] ⇄ [tex]Ca^{2+}(aq)+SO_4^{2-}(aq)[/tex]
The solubility product is defined as the product of the free ions raised to the power of their coefficients, in this case:
[tex]K_{sp}=[Ca^{2+}][SO_4^{2-}]=10^{-4.5}[/tex]
Our idea is to find the solubility quotient, Q, and compare it to the K value. A precipitate will only form if Q > K. If Q < K, the precipitate won't form. In this case:
[tex]Q_{sp}=[Ca^{2+}][SO_4^{2-}]=5.00\cdot10^{-2} M\cdot7.00\cdot10^{-3} M=3.5\cdot10^{-4}[/tex]
Now given the K value of:
[tex]K_{sp}=10^{-4.5}=3.2\cdot10^{-5}[/tex]
Notice that:
[tex]Q_{sp}>K_{sp}[/tex]
This means the precipitate will form, as we have an excess of free ions and the equilibrium will shift towards the formation of a precipitate to decrease the amount of free ions.
What’s the boiling point of water
Answer:
100 °C
Explanation:
Well it actually It depends on temperature and altitude . The boiling point of water is 100 °C or 212 °F at 1 atmosphere of pressure (sea level). However, the value is not a consistent. The boiling point of water depends on the atmospheric pressure, which changes according to elevation.
1. What types of evidence might be found at a bomb scene that could help
investigators catch the bomber? Choose one of the types of evidence that
you've identified and discuss how forensic scientists might find this type of
evidence at the scene and what information it might give them.
Answer:
Substances used to make the bomb
The area it was placed
Which people were in that area
How the bomb was set off
Explanation:
Examining the residues left at the scene by the bomb could tell forensics what the bomb was made out of, and the police could investigate possible leads about people who purchased (or have access to) such materials.
The area should give clues because security cameras could be used to trace who was there that should not be. There would be a possible suspect.
If it is a public place, then we can see if there is anyone of importance (to the suspect) that was there at that time.
If a remote detonator was used to set off the bomb, then the suspect would have to be relatively close to the bomb.
Answer:
Substances used to make the bomb
The area it was placed
Which people were in that area
How the bomb was set off
Why is the chemistry of actinoids complicated?
Answer:
Explanation:
Actinoids are the series have 15 element in the periodic table.
Chemistry of actinoids are complicated because of the following reasons.
Their outer most orbitals are 6d and 7s but most of the electrons resides in 5f orbitals. These orbitals are most exposed to environment and incoming electron picked up by 5f orbital instead of 6d or 7s orbitals.They are radioactive elements that couldn't be handle in normal condition to study their properties. Their f-orbital can accommodate 14 electrons and they have many variable oxidation state.5d electron donot contribute in the formation of chemical bonds.They have a very strong tendency to make complexesMost of the actinoides are artificial and are in very minute in amount. they are in very less quantity that is amounts found in nano-grams so are more expensive too and As they are radioactive so their half life is very short and in very less time the decay occur so couldn't be study as upon decay their actual properties changed.Due to all the above reasons it make difficult for a chemist to study about the chemical properties of actinoids.
Describe the electron distribution in a polar-covalent bond and it's effect on the partial charges of the compound?
Answer:
In polar Covalent bonds, the electrons which are in bonded shifts towards an atom which has more valance electrons.
Explanation:
We know if an atom takes the electron it acquires a negative charge whereas if it gives an electron it acquires a positive charge in the ionic bond. But here we are talking about covalent bonds. Covalent bonds are those in which atoms share the electron instead of completely giving off the electron. If the atoms are identical in case of covalent bond that is 2 hydrogen atoms then this type of bonding is called pure covalent bonds but if the atoms linked in covalent bonds are different then it is called polar covalent bonds.
In this, the bonding electrons will shift towards an atom which has more valence electron thereby acquiring the partial negative charges and the other atom will acquire a partial positive charge. For example, HCl. In this the Chlorine atom is having more valence electron than hydrogen atom, and hence Chlorine atom has a partial negative charge and Hydrogen atom has a partial positive charge.
In polar Covalent bonds, the electrons that are in bonded shifts towards an atom that has more valance electrons.
The following information should be considered:
We know that the atom takes the electron it acquires a negative charge while on the other hand if it gives an electron it acquires a positive charge in the ionic bond. But Covalent bonds are those in which atoms share the electron instead of completely giving off the electron. In the case when the atoms are same in case of covalent bond that is 2 hydrogen atoms so this type of bonding is called pure covalent bonds. But if the atoms linked in covalent bonds are distinct so it is called polar covalent bonds. In this, the bonding electrons will shift towards an atom which has more valence electron thereby acquiring the partial negative charges and the other atom will acquire a partial positive charge.Learn more: https://brainly.com/question/13013054?referrer=searchResults
Part A
CHACHACHCH,CO K+
CH,CH
Spell out the full name of the compound.
Answer:
potassium 3-ethylpentanoate
or
potassium 3-ethylpentanoic acid
Explanation:
This is an organic compound.
This is a salt of carboxylic acid
This compound have 5 carbon main chain
There is an ethyl group is attached on carbon 3
K (Potassium) substituted the H (hydrogen) of pentanoic acid and form salt of it.
This compound shown in ionic form as salt solution written in ionic form.
So,
the name will be
Potassium 3-ethylpentanoate
it is also named as potassium 3-ethylpentanoic acid
Note: you can write any one of them both are right
the structure and name is given in attachment
What is the molar mass of Na2SO3
173 g/mol
118 g/mol
141 g/mol
126 g/mol
Answer:
126g/mol
Explanation:
Molar mass is the mass of all the atoms in a molecule or compound in grams per mole (g/mol or gmol-1). To calculate the molar mass of a molecule, we first obtain the atomic weights of the individual elements in a periodic table. We then count the number of atoms and multiply it by the individual atomic masses.
•Atomic weight of Sodium Na = 23g/mol
•Atomic weight of Sulphur S= 32g/mol
•Atomic weight of Oxygen O = 16g/mol
•Find the sum of the atomic weights / molar masses of all the elements.
We have 2 atoms of Sodium Na and three atoms of Oxygen O. This implies that we will have to multiply the number of their atoms present by their atomic masses/molar masses.
Molar mass of Na2SO3= (number of atoms × atomic mass of Na) + (number of atoms × atomic mass of S) + ( number of atoms × atomic mass of O)
Molar mass of Na2SO3= (2×23g/mol) + (1×32g/mol) + (3×16g/mol)
Molar mass of Na2SO3= 46g/mol + 32g/mol + 48g/mol
Molar mass of Na2SO3 = 126g/mol
Therefore the molar mass of Na2SO3 is 126g/mol
If you guys don’t mind can you explain to me why u think it’s either A, b, c, d plz and thank you
Answer: answer is D
Explanation:
Describe all of the van der Waals forces that exist between molecules of water.
Explanation:
The van der Waals' forces are the forces that exist between the millions of separate water molecules, and not between the hydrogen and oxygen atoms in the case of water. Dipole-Dipole forces are one of van der Waals' three forces. ... For example, HCl comprised of the atom Hydrogen and Chlorine is polar.
NaOH (aq) + H2SO4 (aq) > H2O + NaSO4 (aq)
Answer:
[tex]2 NaOH (aq) + H_2SO_4 (aq)\rightarrow 2 H_2O (l) + Na_2SO_4 (aq)[/tex]
Explanation:
Let's correct and balance the given equation:
[tex]NaOH (aq)[/tex] is sodium hydroxide, charge of sodium is +1, charge of hydroxide is -1, so it's fine;[tex]H_2SO_4 (aq)[/tex] is sulfuric acid, charge of hydrogen cation is +1, charge of sulfate is -2, sulfate is balanced by the two protons;[tex]H_2O (l)[/tex] is firstly a molecule, it's water, in its liquid state, the oxidation state of +1 for the two hydrogens is balanced by the oxidation state of -2 for oxygen;sodium sulfate should be [tex]Na_2SO_4 (aq)[/tex], since sulfate has a charge of -2, this would require two sodium cations to balance it.The equation becomes:
[tex]NaOH (aq) + H_2SO_4 (aq)\rightarrow H_2O (l) + Na_2SO_4 (aq)[/tex]
We require 2 NaOH in order to balance the two sodium cations on the right, this would yield a total of 4 hyrogens on the left, so we also need two water molecules to balance it fully:
[tex]2 NaOH (aq) + H_2SO_4 (aq)\rightarrow 2 H_2O (l) + Na_2SO_4 (aq)[/tex]
Look at the four positions of Earth with respect to the sun. Florida is in the Northern hemisphere. At what position of Earth will Florida experience the first day of spring? (2 points) Question 41 options: 1) Position 1 2) Position 2 3) Position 3 4) Position 4
Florida experiences the first day of spring when Earth is in Position 3 with respect to the Sun. On or about March 21, known as the vernal equinox, neither hemisphere is favored, and the Sun crosses the celestial equator, marking the first day of spring.
Explanation:Florida, which is located in the Northern Hemisphere, experiences the first day of spring when Earth is in Position 3 with respect to the Sun. On or about March 21, known as the vernal equinox, the Sun is on the celestial equator. This means that every place on Earth receives roughly 12 hours of sunshine and 12 hours of night. During this time, neither hemisphere is favored, and the Sun crosses the celestial equator, marking the first day of spring.
it takes 60 days for 1024 grams of element XY to decay to 32 grams. what is the half life of element XY
Answer:
The half life of element XY is 12 days
Explanation:
Given:
Time taken for 1024 grams to decay into 32 grams = 60 days
To Find:
The half life of element XY = ?
Solution:
The Half life is calculated by
[tex]N = N_0 (\frac{1}{2})^{\frac{t}{t_{\frac{1}{2}}}[/tex]
[tex]t_{\frac{1}{2}}[/tex] =[tex]\frac{t}{log_{\frac{1}{2}}( \frac{N(t)}{N_0})}}[/tex]
Substituting the values,
[tex]t_{\frac{1}{2}}[/tex] =[tex]\frac{60}{log_{\frac{1}{2}}( \frac{32}{1024})}}[/tex]
[tex]t_{\frac{1}{2}}[/tex] =[tex]\frac{60}{log_{\frac{1}{2}}(0.03125)}}[/tex]
[tex]t_{\frac{1}{2}}[/tex] =[tex]\frac{60}{5}[/tex]
[tex]t_{\frac{1}{2}}[/tex] = 12
Consider the following intermediate reactions.
CH4(g)+2O2->CO2(g)+2H2O(g) ΔH1=-802 kJ
2H2O(g)->2H2O(I) ΔH2=-88 kJ
The overall chemical reaction is as follows.
CH4(g)+2O2(g)->CO2(g)+2H2O(I) ΔH2=-890 kJ
What is the correct enthalpy diagram using the Hess law for this system?
Answer:
The answer is A on edge
Explanation:
The mass of a neutron is 1.67 x 10^-24 g. Approximately what number of neutrons would equal a mass of one gram?
The number of neutrons that would equal a mass of one gram is approximately 6 x 10^23, which is also known as Avogadro's number.
Explanation:To find the number of neutrons that would equal a mass of one gram, you would need to divide the desired mass (1 gram) by the mass of a single neutron, which is 1.67 x 10^-24 g. So, the calculation would be 1 g / 1.67 x 10^-24 g = approximately 6 x 10^23 neutrons. This number is also known as Avogadro's number, a familiar concept in chemistry and physics.
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1. If you have a 1-g sample of Po-218, how many grams would you
have after 6 minutes? After 18 minutes?
Answer:
a) 0.25 g b) 0.01542 g
Explanation:
Half life of Po-218 = 3.04 minutes
initial mass = 1 g
after 3.04 minutes it will remain 0.5 g
after another 3.04 minutes it will remain 0.25 g
After 6 minutes it will remain approx 0.25 g
B) after another 3.04 minutes it will remain 0.125 g
after another 3.04 minutes it will remain 0.0625 g
after another 3.04 minutes it will remain 0.03125 g
after another 3.04 minutes it will remain 0.015625 g
After 18 minutes it will remain approx 0.01542 g
what is the molarity and molality of a solution prepared by mixing 23g of CaCl2 with 217g of water(assuming density of water is 1g/mol)
Answer:
Molarity = 0.9 M
Molality = 0.95 m
Explanation:
Data given:
mass of CaCl₂ = 23 g
mass of water = 217g
Density of water = 1g/mol
molality of solution = ?
molarity of solution = ?
Solution:
Molarity and Molality are terms used for concenteration of solution
Formula Used for Molarity
Molarity = moles of solute / liter of solution . . . . . (1)
So first we find number of moles of 23 g CaCl₂.
Formula used to find moles
no. of moles = mass in g / molar mass
molar mass CaCl₂ = 40 + 2(35.5)
molar mass CaCl₂ = 40 + 71 = 111 g/ mole
So,
Put values in mole formula
no. of moles = 23 g / 111 g/mol
no. of moles = 0.21 mol
Now,
As for molarity we have to convert grams of water to liter
for this purpose we will use density formula
d= m/v
for volume rearrange the above equation
v = m/d . . . . . . . (2)
put vlue in above equation 2
v = 217 g / 1 (g/mL)
v = 217 mL
Now,
Total amount of solution = 23 + 217 = 240 mL
Now, Convert the mL to Liter
1000 = 1 L
240 mL = 240 /1000 = 0.24 L
So no we have the following required values to find molarity
no. of moles of CaCl₂ = 0.21 mol
liter of solution = 0.24 L
Put values in equation 1
Molarity = 0.21 mol / 0.24 L
Molarity = 0.9 M
_______________
To find Molality (m)
Formula used to find Molality
Molality = moles of solute / kg of solvent . . . . . . . (3)
So, no we have to convert grams of water to Kg
1000 g = 1 kg
217 g = 217 / 1000 = 0.22 Kg
Now,
Put values in equation
Molality = 0.21 mol / 0.22 kg
Molality = 0.95 m
So, the Molality = 0.95 m
H2CO3(aq) + H200 H30 (aq) + HCO3 (aq).
What is the correct equilibrium expression?
© B.
0 C.
Ô D.
"Ka" = (["H"_3"O"A+]["HCO" 3^(-2)/(["H"_2"CO"_3])
"Ka" = (["H"_3"O"A+]["H"_2"CO"_3])/(["HEO"_3^(-1)
"Ka" = (T"H"_2"CO"_3]["H"_2"O"] ["H"_3"O"A+]["HCO"_3^(-)
"Ka" = (["H"_3"O"A+]["HCO"_3^(-1)/(["H"_2"CO"_3]["H"_2"O"]
Answer:
[tex]K_a=\frac{[H_3O^+][HCO_3^-]}{[H_2CO_3]}[/tex]
Explanation:
Several rules should be followed to write any equilibrium expression properly. In the context of this problem, we're dealing with an aqueous equilibrium:
an equilibrium constant is, first of all, a fraction;in the numerator of the fraction, we have a product of the concentrations of our products (right-hand side of the equation);in the denominator of the fraction, we have a product of the concentrations of our reactants (left-hand side o the equation);each concentration should be raised to the power of the coefficient in the balanced chemical equation;only aqueous species and gases are included in the equilibrium constant, solids and liquids are omitted.Following the guidelines, we will omit liquid water and we will include all the other species in the constant. Each coefficient in the balanced equation is '1', so no powers required. Multiply the concentrations of the two products and divide by the concentration of carbonic acid:
[tex]K_a=\frac{[H_3O^+][HCO_3^-]}{[H_2CO_3]}[/tex]
47. Describe the shapes and relative energies of the s, p, d, and f atomic orbitals.
Answer:
S orbital:spherical
P orbital:dumbbell
D orbital:double dumbbell
F orbital:complex
Explanation:
50cm3 of 1 mol/dm3 HCl at 30°C was mixed with 50cm3 of 1mol/dm3 NaOH at 30°C in a styrofoam calorimeter. The temperature of the calorimeter rose by 4.5°C. Calculate the heat of reaction per mol of H20 formed.( heat capacity of the calorimeter is 50J/°C
Answer:
-21 kJ·mol⁻¹
Explanation:
Data:
H₃O⁺ + OH⁻ ⟶ 2H₂O
V/mL: 50 50
c/mol·dm⁻³: 1.0 1.0
ΔT = 4.5 °C
C = 4.184 J·°C⁻¹g⁻¹
C_cal = 50 J·°C⁻¹
Calculations:
(a) Moles of acid
[tex]\text{Moles of acid} = \text{0.050 dm}^{3} \times \dfrac{\text{1.0 mol}}{\text{1 dm}^{3}} = \text{0.050 mol}\\\\\text{Moles of base} = \text{0.050 dm}^{3} \times \dfrac{\text{1.0 mol}}{\text{1 dm}^{3}} = \text{0.050 mol}[/tex]
So, we have 0.050 mol of reaction
(b) Volume of solution
V = 50 dm³ + 50 dm³ = 100 dm³
(c) Mass of solution
[tex]\text{Mass of solution} = \text{100 dm}^{3} \times \dfrac{\text{1.00 g}}{\text{1 dm}^{3}} = \text{100 g}[/tex]
(d) Calorimetry
There are three energy flows in this reaction.
q₁ = heat from reaction
q₂ = heat to warm the water
q₃ = heat to warm the calorimeter
q₁ + q₂ + q₃ = 0
nΔH + mCΔT + C_calΔT = 0
0.050ΔH + 100×4.184×4.5 + 50×4.5 = 0
0.050ΔH + 1883 + 225 = 0
0.050ΔH + 2108 = 0
0.050ΔH = -2108
ΔH = -2108/0.0500
= -42 000 J/mol
= -42 kJ/mol
This is the heat of reaction for the formation of 2 mol of water
The heat of reaction for the formation of mol of water is -21 kJ·mol⁻¹.