Answer:
d. Prevents a drastic change in pH when an acid or base enters a solution.
Explanation:
The purpose of a buffer is to resist pH change and keep the solution relatively stable.
A 1 liter solution contains 0.370 M hypochlorous acid and 0.493 M sodium hypochlorite. Addition of 0.092 moles of barium hydroxide will: (Assume that the volume does not change upon the addition of barium hydroxide.)
In the original solution you have the mixture of a weak acid (Hypochlorous acid) and its conjugate base (Sodium hypochlorite). That is a buffer.
The barium hydroxide will react with hypochlorous acid. If this reaction cause the complete reaction of hypochlorous acid, the buffer break its capacity and the pH change in several units. In this case:
The addition of barium hydroxide will raise the pH slightly because the buffer still working.
The initial moles of those species are:
Hypochlorous acid:
[tex]1L * \frac{0.370mol}{1L} = 0.370 moles[/tex]
Sodium hypochlorite:
[tex]1L * \frac{0.493mol}{1L} = 0.493 moles[/tex]
Now, a strong acid as barium hydroxide (Ba(OH)₂) reacts with a weak acid as hypochlorous acid (HClO) as follows:
Ba(OH)₂ + 2HClO → Ba(ClO)₂ + 2H₂O
For a complete reaction of 0.092 moles of barium hydroxide are required:
[tex]0.092 moles Ba(OH)_2*\frac{2mol HClO}{1molBa(OH)_2} = 0.184 moles HClO[/tex]
As there are 0.370 moles, the moles of HClO after the reaction are:
0.370 moles - 0.184 moles = 0.186 moles of HClO will remain
As you still have hypochlorite and hypochlorous acid you still have a buffer.
Thus, the pH will raise slightly because the amount of acid is decreasing and slightly because the buffer can keep the pH.
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e. Which of the following is a mixture? i. Water ii. Hydrogen iii. Air iv. Iron
water is known as the mixture
Answer:
iv. Iron
water is not a mixture
hydrogen is the simplest element
air is pure
When 1 mole of CO(g) reacts with H2O(l) to form CO2(g) and H2(g) according to the following equation, 2.80 kJ of energy are absorbed. CO(g) + H2O(l)CO2(g) + H2(g) Is this reaction endothermic or exothermic? _________ What is the value of q? kJ
why does D2O
have a higher boiling point than H2O
Answer:
deuterium is heavier isotope of hydrogen need
high weight of atom will lead to higher boiling point
Which of the following is a reduction half-reaction?
Solution : An oxidation reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between tow species an oxidaion reductin reaction is any chemical reaction in which the oxidation number of a molecule atom or ion changes by gaining or losing an electron
Arrange the following in order of increasing melting point: NaCl, H2O, CH4, C6H4(OH)2.
a. NaCl < H2O < CH4 < C6H4(OH)2
b. CH4 < H2O < NaCl < C6H4(OH)2
c. CH4 < H2O < C6H4(OH)2 < NaCl
d. CH4 < C6H4(OH)2 < H2O < NaCl
e. CH4 < NaCl < C6H4(OH)2 < H2O
Explanation:
one thing to know is that higher surface area = higher boiling point.
NaCl has the smallest surface area, so it's the first one.
H2O has less surface area than methane, so it's second.
Methane has more surface area than H20, so it's third.
The big molecule has the most surface area, so it's last
Temperature measures the average kinetic energy of particles of the substances. Melting point is directly proportional to surface area. Therefore, the correct option is option C.
What is temperature?Temperature is used to measure degree or intensity of heat of a particular substance. Temperature is measured by an instrument called thermometer.
Temperature can be measured in degree Celsius °c, Kelvin k or in Fahrenheit. Temperature is a physical quantity. Heat always flow from higher temperature source to lower temperature source.
We can convert these units of temperature into one another. The relationship between degree Celsius and Fahrenheit can be expressed as:
°C={5(°F-32)}÷9
Melting point is directly proportional to surface area. NaCl has the smallest surface area. Water has less surface area than methane. Methane has more surface area than H[tex]_2[/tex]O.
Therefore, the correct option is option C.
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Given the equation: 2C6H10(l) 17 O2(g) ---> 12 CO2(g) 10 H2O(g) MM( g/mol): 82 32 44 18 If 115 g of C6H10 reacts with 199 g of O2 and 49 g of H2O are formed, what is the percent yield of the reaction
Answer:
74%
Explanation:
Step 1: Write the balanced equation
2 C₆H₁₀(l) + 17 O₂(g) ⇒ 12 CO₂(g) + 10 H₂O(g)
Step 2: Determine the limiting reactant
The theoretical mass ratio (TMR) of C₆H₁₀ to O₂ is 164:544 = 0.301:1.
The experimental mass ratio (EMR) of C₆H₁₀ to O₂ is 115:199 = 0.578:1.
Since EMR > TMR, the limiting reactant is O₂.
Step 3: Calculate the theoretical yield of H₂O
The theoretical mass ratio of O₂ to H₂O 544:180.
199 g O₂ × 180 g H₂O/544 g O₂ = 65.8 g H₂O
Step 4: Calculate the percent yield of H₂O
%yield = (experimental yield/theoretical yield) × 100%
%yield = (49 g/65.8 g) × 100% = 74%
Answer:
Percentage yield of H₂O = 74.24%
Explanation:
The balanced equation for the reaction is given below:
2C₆H₁₀ + 17O₂ —> 12CO₂ + 10H₂O
Next, we shall determine the masses of C₆H₁₀ and O₂ that reacted and the mass of H₂O produced from the balanced equation. This is can be obtained as follow:
Molar mass of C₆H₁₀ = 82 g/mol
Mass of C₆H₁₀ from the balanced equation = 2 × 82 = 164 g
Molar mass of O₂ = 32 g/mol
Mass of O₂ from the balanced equation = 17 × 32 = 544 g
Molar mass of H₂O = 18 g/mol
Mass of H₂O from the balanced equation = 10 × 18 = 180 g
SUMMARY:
From the balanced equation above,
164 g of C₆H₁₀ reacted with 544 g of O₂ to produce 180 g of H₂O.
Next, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
164 g of C₆H₁₀ reacted with 544 g of O₂.
Therefore, 115 g of C₆H₁₀ will react to produce = (115 × 544)/164 = 381 g of O₂.
From the calculations made above, we can see that a higher mass (i.e 381 g) of O₂ than what was given (i.e 199 g) is needed to react with 115 g of C₆H₁₀.
Therefore, O₂ is the limiting reactant and C₆H₁₀ is the excess reactant.
Next, we shall determine the theoretical yield of H₂O. This can be obtained by using the limiting reactant as shown below:
From the balanced equation above,
544 g of O₂ reacted to produce 180 g of H₂O.
Therefore, 199 g of O₂ will react to produce = (199 × 180)/544 = 66 g of H₂O.
Thus, the theoretical yield of H₂O is 66 g.
Finally, we shall determine the percentage yield. This can be obtained as follow:
Actual yield of H₂O = 49 g
Theoretical yield of H₂O = 66 g
Percentage yield of H₂O =?
Percentage yield = Actual yield /Theoretical yield × 100
Percentage yield of H₂O = 49/66 × 100
Percentage yield of H₂O = 74.24%
what is the complete ionic equation between the reaction of sodium carbonate and calcium hydroxide to form a precipitate
Answer:
CaCl2(aq) + Na2CO3(aq) → CaCO3(s) + 2NaCl(aq)
Reference:
H.W. Hanna and A. Dittmar; Laboratory Manual for General Chemistry, 4th ed.; Morton Publishing Company, Denver, Colorado
Select all that are true for both a voltaic cell and an electrolytic cell. Group of answer choices There must be a complete circuit to allow electrons to flow. The redox reaction is spontaneous. Oxidation happens at the anode. Reduction happens at the cathode. The redox reaction is non-spontaneous. g
Answer:
There must be a complete circuit to allow electrons to flow. Oxidation happens at the anode. Reduction happens at the cathode.
Explanation:
Select all that are true for both a voltaic cell and an electrolytic cell.
There must be a complete circuit to allow electrons to flow. YES. This is true for both cells.
The redox reaction is spontaneous. NO. This is only true for the voltaic cell.
Oxidation happens at the anode. YES. This is true for both cells.
Reduction happens at the cathode. YES. This is true for both cells.
The redox reaction is non-spontaneous. NO. This is only true for the electrolytic cell.
The statements that have been true for both voltaic and electrolytic cells are:
Option A: There must be a complete circuit to allow electrons to flow.
Option C: Oxidation happens at the anode.
Option D: Reduction happens at the cathode.
The electrolytic cells are the one that converts electrical energy into chemical energy. Voltaic cells convert chemical energy into electrical energy.
From the given options, the best-suited option for both electrolytic and voltaic cells are:
For any of the cells to perform the current flow, the circuit must be complete. Option A stating that there must be a complete circuit to allow electrons to flow is correct.The redox reaction has been a spontaneous reaction and results in the chemical conversion to form energy. Since the chemical energy has been converted into electrical energy, statement B has been true for only Voltic cells. Thus option B is incorrect.Oxidation is the reaction to the loss of electrons. In both cells, oxidation happens at the anode. Thus, option C is correct.Since oxidation takes place at anode, cathode acts as the reduction end in both the cells. Thus option D is correct.The redox reaction has been non-spontaneous only in the electrolytic cell. Thus option E is incorrect.The statements that have been true for both voltaic and electrolytic cells are, Option A, C, and D.
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Determine the rate of reaction based on the data below:
75-
rate of reaction = y
hydrogen produced (cm)
х
y
25
50
75
100
125
time (seconds)
Answer:
75
Explanation:
is the answer for your question
0. When measuring tert-butyl alcohol for this experiment, a student first weighs an empty graduated cylinder, then pours 15 mL of the alcohol into the graduated cylinder and weighs the cylinder again. He records the amount of alcohol used as the difference in these two masses. What is wrong with this method
Answer:
Both have solutions in the graduated cylinder.
Explanation:
Recording the amount of alcohol used as the difference between two masses is the wrong method used for measuring tert-butyl alcohol for the experiment. For measuring tert-butyl alcohol for this experiment, the student has to measure the two masses when both the graduated cylinders has solution of tert-butyl alcohol not when one of it is empty (having no tert-butyl alcohol ).
The wrong aspect is that the liquid didn't need to be weighed. Instead the volume should have been recorded with the aid of the graduated cylinder.
What is a Graduated cylinder?This is a cylinder with marked readings and is used to measure the volume of liquids in the laboratory.
The graduated cylinder will accurately measure the amount of alcohol used due to it being volatile and the mass fluctuating during the measurement.
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Deduce the formula of calcium Phosphide.
Answer:
[tex]{ \sf{Ca _{3} P_{2} }}[/tex]
Which processes occur during the second stage of technological design? Check all that apply.
designing a solution
studying relevant information
rebuilding and retesting
reporting a solution
defining criteria of success
identifying a problem
building a prototype
How many nitrate ions are present in the following aqueous solution?
5.08 L of a solution containing 2.68 x 1021 formula units of lithium nitrate per liter.
When you have the number, determine its log (base 10) and enter that value with 3 decimal places
Answer:
22.1
Explanation:
Step 1: Calculate the number of formula units of lithium nitrate
A 5.08 L solution contains 2.68 × 10²¹ formula units per liter.
5.08 L × 2.68 × 10²¹ formula units/1 L = 1.36 × 10²² formula units
Step 2: Calculate the number of nitrate ions
Lithium nitrate dissociates completely in water according to the following equation.
LiNO₃(aq) ⇒ Li⁺(aq) + NO₃⁻(aq)
The molar ratio of LiNO₃ to NO₃⁻ is 1:1. The number of nitrate ions is 1/1 × 1.36 × 10²² = 1.36 × 10²².
Then,
log (1.36 × 10²²) = 22.1
The number of nitrate ions are present in the following aqueous solution is 13.6x10²¹, and log(base 10) value of this is 22.2.
What are strong electrolytes?
Those salts which are completely dissociate into their ions in the solution form will known as strong electrolyte.
Lithium nitrate is a strong electrolyte and it shows complete dissociation as:
LiNO₃ → Li⁺ + NO₃⁻
Given that,
1 liter of solution containing = 2.68 x 10²¹ formula unit
5.08 L of solution containing = 5.08 x 2.68 x 10²¹ = 13.6x10²¹ formula unit
So, number of nitrate ion in given solution = 13.6x10²¹ formula unit
Log(13.6x10²¹) = 22.1
Hence, required values are 13.6x10²¹ and 22.1.
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Why benzene is called aromatic compound according to Huckel’s rule?
Answer:
It obeys rule
Explanation:
Benzene is an aromatic hydrocarbon because it obeys Hückel's rule.
Answer:
Benzene is an aromatic compound because it is planar, cyclic, conjugated and has (4n +2) π electrons, where n= 1.
Explanation:
Hückel's rule states that a molecule is aromatic if it is planar, cyclic, conjugated and has (4n +2) π electrons.
Breaking it down into 4 requirements, we have:
planarcyclicconjugated(4n +2) π electronsLet's look at each of the 4 parts!
What is planar?
Planar refers to the molecule being flat. When an atom is sp² hybridized, it is in a trigonal planar geometry. Let's look at the benzene molecule. Each carbon is attached to 3 other atoms, namely 2 carbons and 1 hydrogen. This means that each carbon is sp² hybridized, making the molecule planar.
Cyclic
This refers to the molecule having a closed ring shape. Benzene fulfils this criteria.
Conjugation
This refers to a system of connected p orbitals, which allows π electrons to delocalize. Each carbon atom in benzene has one 2p orbital, making benzene a conjugated molecule. For molecules that are not cations or anions, conjugated molecules are those that have alternating single and double bonds.
(4n +2) π electrons
n is an integer (e.g. 0, 1, 2, 3) thus for the molecule to be aromatic, it can have 2, 6 or 10 π electrons (non exhaustive). This separates an aromatic compound from an antiaromatic compound, which has 4n π electrons instead.
Benzene has 6 π electrons, so n has a value of 1 in this case.
Thus, benzene is an aromatic compound because it is planar, cyclic, conjugated and has (4n +2) π electrons.
_______
Counting the number of π electrons
Let's look at π bonds!
A double bond is made up of 1 σ bond and 1 π bond, and each π bond is made up of 2 π electrons. We do not count the number of single bonds since single bonds are made up of 1 σ bond only.
There are 3 double bonds in the Kekulé structure of benzene. Thus, the number of π electrons in benzene is 3(2)= 6.
Attached diagrams
Kekulé structure of benzenesp² hybridized carbon6 p orbitals in benzene ringWhich chemical can remove color of red/Pink phenol and make it clear like water transparent?
How many grams of Al were reacted with excess HCl if 3.86 L of hydrogen gas were collected at STP in the following reaction?
2 Al (s) + 6 HCl (aq) → 2 AlCl₃ (aq) + 3 H₂ (g)
The amount, in grams, of Al that reacted with excess HCl if 3.86 L of hydrogen gas were collected at STP in the reaction would be 3.099 grams.
Stoichiometric problemFrom the equation of the reaction, the mole ratio of Al that reacts with that of hydrogen gas that forms is 2:3.
At STP, 1 mole of any gas is equivalent to 22.4 Liters of the gas.
But only 3.86 L of hydrogen was formed in the reaction.
The equivalent mole of 3.86 L hydrogen at STP would be:
3.86 x 1/22.4 = 0.1723 moles
From the mole ratio, the equivalent mole of Al that will produce 0.1723 moles of hydrogen gas would be:
0.1723 x 2/3 = 0.1149 moles
Recall that: mass = mole x molar mass
Mass of 0.1149 moles Al = 0.1149 x 26.98
= 3.099 grams
Thus, the amount of Al that reacted with excess HCl is 3.099 grams.
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explain chlorination of methane
Answer:
Methane and chlorine
If a mixture of methane and chlorine is exposed to a flame, it explodes - producing carbon and hydrogen chloride. This is not a very useful reaction! The reaction we are going to explore is a more gentle one between methane and chlorine in the presence of ultraviolet light - typically sunlight. This is a good example of a photochemical reaction - a reaction brought about by light.
CH4+Cl2+energy→CH3Cl+HCl(3.4.2)
The organic product is chloromethane. One of the hydrogen atoms in the methane has been replaced by a chlorine atom, so this is a substitution reaction. However, the reaction doesn't stop there, and all the hydrogens in the methane can in turn be replaced by chlorine atoms.
Substitution reactions happen in which hydrogen atoms in the methane are replaced one at a time by chlorine atoms. You end up with a mixture of chloromethane, dichloromethane, trichloromethane and tetrachloromethane.
I hope this help you!:)
Explanation:
Aspirin that has been stored for a long time may give a vinegar like odour and give a purple colour with FeCl3. What reaction would cause this to happen
?.
Answer:
See explanation
Explanation:
The IUPAC name of aspirin is 2-Acetoxybenzoic acid. It is composed of an acetoxy moiety and a benzoic acid moiety.
The compound can be hydrolysed under prolonged storage conditions to yield acetic acid which causes the vinegar like odour.
Also, one of the products of this hydrolysis bears a phenol group which reacts with FeCl3 to give a purple color.
how many moles of oxygen atoms are present in 0.4 moles of oxygen gas
Answer:
Each molecule of O2 is made up of 2 oxygen atoms. So 1 mole of O2 molecules is made up of 2 moles of oxygen atoms. Therefore 1 mole of oxygen gas contains 2 moles of oxygen atoms. And 0.4 moles of oxygen gas contains 0.8 moles of oxygen atoms.
There are 0.8 moles of oxygen atoms in 0.4 moles of oxygen gas.
Oxygen gas (O₂) consists of two oxygen atoms bonded together. Therefore, to determine the number of moles of oxygen atoms present in a given amount of oxygen gas, we can simply multiply the number of moles of oxygen gas by the number of oxygen atoms per molecule, which is 2.
Given that we have 0.4 moles of oxygen gas, we can calculate the number of moles of oxygen atoms as follows:
Number of moles of oxygen atoms = Number of moles of oxygen gas × Number of oxygen atoms per molecule
= 0.4 moles × 2
= 0.8 moles
Therefore, there are 0.8 moles of oxygen atoms present in 0.4 moles of oxygen gas.
This calculation is based on the stoichiometry of oxygen gas, which indicates that each molecule of O₂ contains two oxygen atoms. By considering the mole ratio between oxygen gas and oxygen atoms, we can determine the number of moles of oxygen atoms in a given quantity of oxygen gas.
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Which method of separation would be most appropriate for separating a mixture of water and alcohol?
A. evaporation
B. chromatography
C. distillation
D. filtration
Answer:C. distillation
Explanation:
Compounds having different boiling points when mixed can be separated by Fractional distillation.
Now when there is a mixture of water and alcohol, Upon heat, we would see that the alcohol will boil at a lower temperature than water for eg, ethanol will boil at 78.5 degrees Celsius, vaporizes and distills into the fractionating columns leaving the water which we know boils at 100 degrees Celsius.
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Please guys please answer this
Answer:
1. Because the rules will keep you safe it prevents you from getting hurt.
2.i) don't taste chemical
ii) Always wear protective gears
iii) be careful with tool
iv) wear protective gloves
Explanation:
help everyone get out quickly
Calculate [H3O+] for pH 1.86. Steps please.
Answer:
[H₃O⁺] = [H⁺] = 10^-pH = 10⁻¹°⁸⁶ = 0.0138M in [H⁺]
Explanation:
By definition pH = -log[H⁺] => [H⁺] = 10^-pH = 10⁻¹°⁸⁶ = 0.0138M in [H⁺]
Using your calculator ... I am using a TI-30XA scientific calculator.
=> start by entering the number 1.86 => then press the (+/-) function => this will insert a negative symbol => -1.86,=> next find button with "2nd" printed on face (on some calculators the button is in yellow); press this button to change to 'secondary mode',=> find the symbol (10ˣ) ... the button below this symbol is usually the 'log' button, then press it => the answer of interest will show in the display window. => ...Depending on the calculator, the answer may show as 0.0138, or 1.38x10⁻², or 1.38E-2 (=1.38 x 10⁻²). It is the user's job to insert dimensional units into answer of interest => 0.0138M, or 1.38 x 10⁻²M, or 1.38E-2M.
1.38E-2 which is 1.38 x 10⁻².
Assume you have 4 solids (A, B, C and D) of similar mass. Which of these requires the greatest energy input to melt?
polar covalent
covalent network
ionic compound
nonpolar covalent
The solid that require the greatest energy input to melt by mass is the option;
Covalent network
Reason for the above answer is as follows;
The elementary particles of a solid are held together by bonds that require
an input of energy to unlock, and once broken, the particles are then able
to change location within their containing vessels with less restrictions
Types of bonds
Polar covalent molecular solids have the following characteristics;a) Soluble in water b) Low melting point, b) Conduct electricity
Solids that are made up of a covalent network have the following characteristicsa) High melting point temperature b) Non conductive of electricity c) Not soluble in water
Solids of ionic compounds have the following characteristics;a) High melting point temperature b) The liquid state and solution
conducts electricity c) Soluble in water
Solids that have nonpolar covalent bonds have;a) Low melting point b) Normally in the gaseous or liquid state b) Not water soluble
Therefore, the covalent network, and the solids ionic compounds require the most energy to melt, however, the strength of the ionic bond in an ionic compound is a factor the charges present and the sizes of the atom, while
the covalent network solid, are combined to form essentially as a single
molecule and therefore require the greatest heat energy input break the bonds of the molecule down in order to melt
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Predict the missing component in the nuclear equation.
238 92U → 234 90Th + X
A. 4 2He
B. 0 -1e
C. 0 0v
Answer:
A
Explanation:
helium (alpha particle)
What information does the first quantum number of an electron give?
A. The sublevel that the electron is in
B. The specific orbital the electron is in
C. The energy level the electron is in
D. The spin that the specific electron has
Answer:
с
Explanation:
the first quantum number of an electron gives the information about the energy level the electron is in
The information first quantum number of an electron give is the energy level the electron is in.
What are quantum numbers?Quantum numbers is a set of symbols which gives idea about the position of electron present inside an atom.
First quantum number is denoted by symbol 'n' which gives idea about the number of shell or energy level in which electron is present.The sublevel that the electron is in is the second quantum number denoted by symbol 'l'.The specific orbital in which electron is present is denoted by symbol 'm' and it is the third quantum number.The spin that the specific electron has is the forth quantum number and denoted by symbol 's'.Hence first quantum number of electron gives ideal about the energy level.
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Which substance has the highest boiling point?
Select the correct answer below:
A) ethyl ether
B) ethyl alcohol
C) water
D) these all have the same boiling point
Answer:
D) these all have the same boiling point
calcium is added to water,the liberated gas is
Answer:
In both cases, the gas evolved is H2. When calcium reacts with water the heat evolved is not suffcient for hydrogen to catch fire. On the other hand, sodium metal reacts with water violently and in this case a lot of heat is evolved which is sufficient for hydrogen to catch fire.
Explanation:
may this answer is helpful for you
Hydrogen
The reaction is given by
[tex]\boxed{\sf {Ca\atop Calcium}+{H_2O\atop Water}\longrightarrow {Ca(OH)_2\atop Calcium\:Hydroxide}+{H_2\atop Hydrogen}}[/tex]
Balanced equation:-
[tex]\boxed{\sf {Ca\atop Calcium}+{2H_2O\atop Water}\longrightarrow {Ca(OH)_2\atop Calcium\:Hydroxide}+{H_2\atop Hydrogen}}[/tex]
A skydiver slows down from 65 m/s to 5 m/s by opening the parachute. If this
takes 0.75 seconds, what is the skydiver's acceleration?
A. 45 m/s2 up
B. 80 m/s2 up
C. 45 m/s2 down
D. 80 m/s2 down
Answer:
D. -80m/s^2
Explanation:
V = u + at
5 = 65 + a (0.75)
0.75a = -60
a = -60/0.75
a = -80m/s^2
Therefore, is decelerating at 80m/s^2
Answer:
[tex]\boxed {\boxed {\sf D. \ 80 \ m/s^2 \ down}}[/tex]
Explanation:
We are asked to find the acceleration of a skydiver. Acceleration is the change in velocity over the change in time, so the formula for calculating acceleration is:
[tex]a= \frac{v_f-v_i}{t}[/tex]
The skydiver was initially traveling 65 meters per second, then he slowed down to a final velocity of 5 meters per second. He slowed down in 0.75 seconds.
[tex]\bullet \ v_f = 5 \ m/s \\\bullet \ v_i= 65 \ m/s \\\bullet \ t= 0.75 \ s[/tex]
Substitute the values into the formula.
[tex]a= \frac{ 5 \ m/s - 65 \ m/s}{0.75 \ s}[/tex]
Solve the numerator.
[tex]a= \frac{-60 \ m/s}{0.75 \ s}[/tex]
Divide.
[tex]a= -80 \ m/s^2[/tex]
The acceleration of the skydiver is -80 meters per second squared or 80 meters per second squared down. The skydiver is slowing down or decelerating, so the acceleration is negative or down.
Cho biết độ tan của NH4Cl trong nước ở 20oC và 70oC lần lượt là 37,2 g/100 gam nước và 60,2 gam/100 g nước. Hòa tan 166,8 gam NH4Cl vào 400 gam nước ở 70oC thu được dung dịch X. Sau đó, hạ nhiệt độ dung dịch X xuống 20oC. Tính khối lượng (gam) NH4Cl kết tinh lại trong X?
Answer: Hợp chất CTHH 0 °C 10 °C 20 °C 30 °C 40 °C 50 °C 70 °C
Actini(III) hydroxide Ac(OH)3 0,0022
Amonia NH3 1176 900 702 565 428 333 188
Amoni azua NH4N3 16 25,3 37,1
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