Answer:
True.
Explanation:
There are three ways to make a buffer.
a. Generating a solution of a weak acid and its conjugate base.
b. Adding to a solution of a weak acid a certain quantity of
strong base, so that the acid remains in excess.
c. adding a limited amount to a conjugate base solution
of strong acid so that the base remains in excess.
We are in c, in this situation.
How do you calculate, pH? We apply Henderson Hasselbach.
pH = pka + log (mmoles base - mmoles acid)/ mmoles acid
pH = pKa + log ((20 ml . 1 M - 1 ml . 10M) / 10 mmoles
pH = 4.76 + log 1 → 4.76 ⇒ pH = pKa
Cuando realizamos la "Estructura de
Puntos de Lewis" ¿Qué es lo que se
utiliza para su representación? *
Answer:
Electrones de valencia.
Explanation:
¡Hola!
En este caso, dado en química se conocen las estructuras de Lewis como representaciones gráficas de como los elementos están enlazados entre sí, debemos tener en cuenta que estos enlaces se forman entre los electrones de valenciam, los cuales son utilizados para su representación. Se sabe que los electrones de valencia son representados con puntos alrededor del elemento a través de puntos que se unen entre sí y son el número de electrons en la capa más externa de los elementos en cuestión; por ejemplo, cloro tiene 7 electrones de valencia, azufre tiene 6, hidrogeno 1, carbono 4 y así sucesivamente.
¡Saludos!
Geckos and some other animals can climb smooth surfaces. Which of these explanations of this
observation do you think is most reasonable?
The gecko's feet are rough, which increases the friction with the surface.
The gecko's feet have tiny suction cups on them that stick to the surface
The gecko's feet secrete a sticky substance that helps them adhere to the surface
The gecko's feet contain molecules that are attracted to the molecules on the surface.
Answer:
The gecko's feet have tiny suction cups on them that stick to the surface.
Answer:
c) pillars
Explanation:
What minimum energy is required to excite a vibration in HF?
Express your answer in joules to three significant figures.
En=(n+12)hν is the equation
Answer:
The energy of a vibrating molecule is quantized much like the energy of an electron in the hydrogen atom. The energy levels of a vibrating molecule are given by the equation: En=(n+21)hv where n is a quantum number with possible values of 1, 2, ... and v is the frequency of vibration.
Explanation:
hope it helps.
have a wonderful day!
How does wavelength affect the pitch of a sound?
a. the shorter the wavelength, the lower the pitch
b. the longer the wavelength, the lower the pitch
c. the taller the wavelength, the lower the pitch
d. none of these
Answer:
D
Explanation:
because the higher the wavelength the shorter the pitch and the shorter the wavelength the higher the pitch
A 0.175 M solution of an enantiomerically pure chiral compound D has an observed rotation of +0.27° in a 1-dm sample
container. The molar mass of the compound is 133.0g/mol.
What is the specific rotation of D?
Answer:
The specific rotation of D is 11.60° mL/g dm
Explanation:
Given that:
The path length (l) = 1 dm
Observed rotation (∝) = + 0.27°
Molarity = 0.175 M
Molar mass = 133.0 g/mol
Concentration in (g/mL) = 0.175 mol/L × 133.0 g/mol
Concentration in (g/mL) = 23.275 g/L
Since 1 L = 1000 mL
Concentration in (g/mL) = 0.023275 g/mL
The specific rotation [∝] = ∝/(1×c)
= 0.27°/( 1 dm × 0.023275 g/mL )
= 11.60° mL/g dm
Thus, the specific rotation of D is 11.60° mL/g dm
Which of the following examples from everyday life are made possible or explained possible or explained by modern chemistry
Answer: Where is the folowing?
Explanation:
In going from room temperature 25° to 35 the rate of a reaction doubles calculate the activation energy for the reaction
Answer:
52.9 KJmol-1
Explanation:
From;
log(k2/k1) = Ea/2.303 * R (1/T1 - 1/T2)
The temperatures must be converted to Kelvin;
T1 = 25° C + 273 = 298 K
T2= 35°C + 273 = 308 K
R= gas constant = 8.314 JK-1mol-1
Substituting values;
log 2 = Ea/2.303 * 8.314 (1/298 - 1/308)
Ea = 52.9 KJmol-1
A compound composed of 3.3% H, 19.3% C, and 77.4% O3.3% H, 19.3% C, and 77.4% O has a molar mass of approximately 60 g/mol.. What is the molecular formula of the compound?
Answer:
Molecular formula of the compound = H₂CO₃
Explanation:
First, the empirical formula of the compound is determined
Percentage by mass of each element is given as shown below:
H = 3.3% ; C = 19.9%; O = 77.4%
Mole ratio of the elements= percentage mass/ molar mass
H = 3.3/ 1 = 3.3
C = 19.3/12 = 1.6
O = 77.4/16 = 4.8
whole number ratio is obtained by dividing through with the smallest ratio
H = 3.3/1.6; C = 1.6/1.6; O = 4.8/1.6
H : C : O = 2 : 1 : 3
Empirical formula = H₂CO₃
Molecular formula/mass = n(empirical formula/mass)
60 = n(2*1 + 12*1 + 16*3)
60 = n(62)
n = 60/62 = 0.96
n is approximately = 1
Therefore, molecular formula of the compound = (H₂CO₃) * 1
Molecular formula of the compound = H₂CO₃
The molecular formula of a compound composed of 3.3% H, 19.3% C, and 77.4% O and a molar mass of approximately 60 g/mol is CH2O3.
HOW TO CALCULATE MOLECULAR FORMULA:
The molecular formula of an unknown compound can be calculated from the empirical formula. The empirical formula can be calculated as follows:C = 19.3% = 19.3gH = 3.3% = 3.3gO = 77.4% = 77.4gFirst, we calculate the number of moles in each element by dividing by their respective atomic mass. C = 19.3g ÷ 12g/mol = 1.61molH = 3.3g ÷ 1g/mol = 3.3molO = 77.4g ÷ 16g/mol = 4.84molNext, we divide by the smallest mole value. C = 1.61mol ÷ 1.61 = 1 H = 3.3mol ÷ 1.61 = 2.05O = 4.84mol ÷ 1.61 = 3.01Approximately, the empirical ratio of CHO is 1:2:3. Hence, the empirical formula is CH2O3. {CH2O3}n = 60g/mol{12 + 2 + 48}n = 6062n = 60n = 60 ÷ 62n = 0.968n = 1Therefore, the molecular formula of a compound composed of 3.3% H, 19.3% C, and 77.4% O and a molar mass of approximately 60 g/mol is CH2O3.Learn more at: https://brainly.com/question/21280037?referrer=searchResults
If you are given the wavelength and speed of a wave, the formula you use to calculate the frequency is
Answer:
Frequency x Wavelength = Speed of wave
Explanation:
So, if you take the Speed and divide it by wavelength then you get the frequency.
What element in period 4 has the lowest ionization energy? noble gas, alkali metal, halogen or alkaline earth metal?
Answer:
alkali metal
Explanation:
The alkali metals in period 4 will have the lowest ionization energy of the elements in the period.
Across a period ionization energy increases progressively from left to right due to decreasing atomic radii caused by the increasing nuclear charge which is not compensated for by successive electronic shells.
Ionization energy is the energy needed to remove the most loosely bound electrons of an atom in the gas phase in the ground state. The measure of the readiness of an atom to lose an electron is the ionization energy.Down a group, it decreases.
The periodic table is the arrangement of the elements based on the atomic numbers. The elements of the alkali period have the lowest ionization energy.
What is ionization energy?Ionization energy or the potential is the amount of the potential needed by the molecule or the atom to remove the electron from their shells. The alkali metal elements have the lowest ionization energy.
The ionization potential of the elements increases from the left towards the right of the period due to the decrease in the atomic radii and decreases from top to bottom in a group.
In the period from left to right the atomic radius of the atoms decreases due to the increase in the nuclear charge of the atoms.
Therefore, option B. alkali metal has the lowest ionization energy.
Learn more about ionization energy here:
https://brainly.com/question/837763
Which element has a greater electronegativity?
fluorine (9) or radium (88)
Answer:
Fluorine
Explanation:
Electronegativity increases as you go from left to right across the periodic table and decreases as you go from top to bottom of the periodic table.
Fluorine is in period 3, group 17
Radium is in period 7, group 2
Radium is in period 7 and we know that electronegativity decreases as you move from top to bottom.
Explanation: As you move from top to bottom, you are in higher energy level, which means that your distance from the nucleus is further away.
Answer:
Fluorine
General Formulas and Concepts:
Chemistry
Reading a Periodic TablePeriodic TrendsElectronegativity - the tendency for an element to attract an electron to itselfZ-effective and Coulomb's Law, Forces of AttractionExplanation:
The Periodic Trend for Electronegativity is up and to the right of the Periodic Table.
Fluorine is Element 9 and has 9 protons. Radium is Element 88 and has 88 protons. Therefore, Radium has a bigger Zeff than Flourine.
However, since Radium is in Period 7 while Fluorine is in Period 2, Radium has more core e⁻ than Fluorine does. This will create a much larger shielding effect, causing Radium's outermost e⁻ to have less FOA between them. Fluorine, since it has less core e⁻, the FOA between the nucleus and outershell e⁻ will be much stronger.
Therefore, Fluorine would attract an electron more than Radium, thus bringing us to the conclusion that Fluorine has a higher electronegativity.
How many moles of H20 are required to react completely with 7.30 moles of NO2?
3NO2(g) + H20(1)
NO(g) + 2HNO3(aq)
1.86 mol
2.19 mol
2.43 mol
6.12 mol
7.30 mol
Answer:
2.43 moles of water are required.
Explanation:
Given data:
Moles of H₂O required = ?
Moles of NO₂ present = 7.30 mol
Chemical equation:
3NO₂+ H₂O → NO + 2HNO₃
Now we will compare the moles of NO₂ and H₂O.
NO₂ : H₂O
3 : 1
7.30 : 1/3×7.30 = 2.43 mol
If a friend is making lemonade from an instant mix, which set of conditions would lead to a faster rate of dissolving the mix in the pitcher of water? Cold water and powdered lemonade Cold water and lemonade tablets Warm water and powdered lemonade Warm water and lemonade tablets
Answer: Warm Water and powdered lemonade.
Explanation: Water is faster at dissolving something and powder takes a smaller effort to dissolve.
Answer:
C
Explanation:
The velocity of a car changes from 10 m/s east to 30 m/s east in 4 seconds.
What is the acceleration of the car?
A. 5 m/s2 east
B. 10 m/s2 west
c. 10 m/s2 east
D. 5 m/s2 west
Answer:
5m/s²
Explanation:
Given parameters:
Initial velocity = 10m/s due east
Final velocity = 30m/s due east
Time = 4s
Unknown:
Acceleration of the car = ?
Solution:
Acceleration is the rate of change of velocity with time.
Mathematically;
Acceleration = [tex]\frac{v - u}{t}[/tex]
v is the final velocity
u is the initial velocity
t is the time taken
Insert the parameters and solve;
Acceleration = [tex]\frac{30 - 10}{4}[/tex] = 5m/s²
How many atoms of Chlorine would there be in 6.8 mol of Cl?
Answer:
241.08039999999588
Explanation:
3. Which of the elements listed below would you expect to form ions with a positive one charge?
Chlorine
Lithium
Sodium
Magnesium
Answer:
Lithium and Sodium
Explanation:
Silver has a density of 10.5 g/cm³, and gold has a density of 19.3 g/cm³. Which would have a greater mass, 5 cm³ of silver or 5 cm³ of gold?
Gold have a greater mass
Further explanationDensity is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
The unit of density can be expressed in g/cm³ or kg/m³
Density formula:
[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]
ρ = density
m = mass
v = volume
mass of Silver :[tex]\tt mass=\rho\times V\\\\mass=10.5\times 5=52.5~g[/tex]
mass of Gold :[tex]\tt mass=\rho\times V\\\\mass=19.3\times 5=96.5~g[/tex]
A balloon is filled to a volume of 1.50 L with 3.00 moles of gas at 25 °C. With pressure and temperature held constant, what will be the volume (in L) of the balloon if 0.80 moles of gas are added?
We know, when temperature and pressure is constant :
[tex]\dfrac{V_1}{n_1}=\dfrac{V_2}{n_2}[/tex] ....1)
[tex]n_1 = 3\ moles,\ V_1 = 1.50\ L[/tex]
[tex]n_2 = 3 + 0.80 = 3.80 \ moles[/tex]
Let, final volume is [tex]V_2[/tex].
Putting all values in equation 1), we get :
[tex]\dfrac{V_1}{n_1}=\dfrac{V_2}{n_2}\\\\\dfrac{1.50}{3}=\dfrac{V_2}{3.80}\\\\V_2 = \dfrac{1.50\times 3.80}{3}\\\\V_2 = 1.9\ L[/tex]
Therefore, volume (in L) of the balloon if 0.80 moles of gas are added is 1.9 L.
Hence, this is the required solution.
Mitosis occurs during which phase?
Answer:
Prophase
Explanation:
Prophase is the first stage in mitosis, occurring after the conclusion of the G2 portion of interphase. During prophase, the parent cell chromosomes — which were duplicated during S phase — condense and become thousands of times more compact than they were during interphase.
How many moles of water would be produced from 3 moles of oxygen in the following reaction? Don’t forget to include units in your answer.
PLZHELP I'LL AWARD BRAINLIEST
Answer:
6 mol H₂O
General Formulas and Concepts:
Chemistry
StoichiometryExplanation:
Step 1: Define
RxN: 2H₂ + O₂ → 2H₂O
Given: 3 moles O₂
Step 2: Stoichiometry
[tex]3 \ mol \ O_2(\frac{2 \ mol \ H_2O}{1 \ mol \ O_2} )[/tex] = 6 mol H₂O
Step 3: Check
We are given 1 sig fig.
Our final answer has 1 sig fig, so no need to round.
A chemist conducts an experiment in which 2.0 L of hydrogen gas is collected over water at 1 atm and 298 K. Remember the pressure due to the hydrogen gas is 0.97 atm. Using the combined gas law, calculate the volume in L of the dry hydrogen gas at 273 K and a pressure of 1 atm.
Answer:
[tex]V_2=1.80L[/tex]
Explanation:
Hello!
In this case, since in this problem we can see that the volume, pressure and temperature are changing, considering that the vapor pressure of water at 0 °C or also 273 K is 0.006 atm, the pressure of dry hydrogen would be 0.99 atm, thus, we can write:
[tex]\frac{P_1V_1}{T_1} =\frac{P_2V_2}{T_2}[/tex]
Now, as we need the final volume V2, by solving for it, we write:
[tex]V_2=\frac{P_1V_1T_2}{T_1P_2}[/tex]
In such a way, we plug in the given data to obtain:
[tex]V_2=\frac{0.97atm*2.0L*273K}{298K*0.99atm}\\\\V_2=1.80L[/tex]
Which means that the underwent a compression.
Best regards!
Taking into account the combined gas law, the volume of the dry hydrogen gas at 273 K and a pressure of 1 atm is 1.78 L.
Gay Lussac's LawGay-Lussac's law states that when there is a constant volume, as the temperature increases, the pressure of the gas increases. And when the temperature is decreased, the pressure of the gas decreases.
Mathematically, this law indicates that the quotient between pressure and temperature is constant:
[tex]\frac{P}{T}=k[/tex]
Boyle's LawBoyle's law says that the volume occupied by a certain gaseous mass at constant temperature is inversely proportional to pressure.
Boyle's law is expressed mathematically as:
P× V = k
Charles's lawCharles's law states that for a given sum of gas at constant pressure, as the temperature increases, the volume of the gas increases and as the temperature decreases, the volume of the gas decreases. That is, temperature and volume are directly proportional.
In summary, Charles's law is a law that says that when the amount of gas and pressure are kept constant, the ratio that exists between the volume and the temperature will always have the same value:
[tex]\frac{V}{T}=k[/tex]
Combined gas lawCombined law equation is the combination of three gas laws called Boyle's, Charlie's and Gay-Lusac's law:
[tex]\frac{PxV}{T}=k[/tex]
Studying two different states, an initial state 1 and a final state 2, it is satisfied:
[tex]\frac{P1xV1}{T1}=\frac{P2xV2}{T2}[/tex]
This caseIn this case you know:
P1= 0.97 atmV1= 2 LT1= 298 KP2= 1 atmV2= ?T2= 273 atmReplacing in the combined gas law:
[tex]\frac{0.97 atmx2 L}{298 K}=\frac{1 atmxV2}{273 K}[/tex]
Solving:
[tex]\frac{0.97 atmx2 L}{298 K}\frac{273 K}{1 atm} =V2[/tex]
1.78 L= V2
In summary, the volume of the dry hydrogen gas at 273 K and a pressure of 1 atm is 1.78 L.
Learn more about the combined gas law:
https://brainly.com/question/4147359?referrer=searchResults5. What is the speed (Velocity) of a cyclist who covers 10 km (convert to meters
first!) in 14 minutes and 30 seconds? Remember time must be in seconds first!
[tex]\mathfrak{\huge{\pink{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the Concept of the Kinematics.
Here, we know that, Velocity = Distance / Time,
So here, Distance = 10km = 10×1000 = 10000 metres.
, Time = 14 min 30 sec = 870 seconds,
so now, we get velocity as,
=> V = 10000 ÷ 870 => 11.49 m/s .
Hence, Velocity is 11.49 m/s.
only number 3 please
Explanation:
1. total electrons = 22
thus element = titanium2. total electrons = 31
thus element = Galium3. total electrons = 37
thus element = Rubidiumhope it helps:)
Answer:
1.Argon
2. Scandium
3. Cobalt
What is accretion?????
Answer:
the process of growth or increase, typically by the gradual accumulation of additional layers or matter.
Explanation:
Answer:
The process of growth or increase, typically by the gradual accumulation of additional layers or matter.
Explanation:
What happens when two cars converge
2. What type of answers will an investigator use to determine if a fire is arson?
Your answer:
Physical and Chemical
O Gas and Liquid
O None of the above
O All of the above
Answer:
What is this asking for?
Explanation:
I’ll put the answer in the comments
and have
more energy moving from left to right on the electromagnetic
Electromagnetic waves are
radiation diagram
shorter/less
o longer/more
shorter/more
longer/less
Answer:
longer/less
Explanation:
In moving from left to right on the electromagnetic diagram, the wavelength becomes longer and the energy lessens.
The electromagnetic diagram presents a spectrum of radiation.
The left most wave is the most energetic and the right most radiation is the least energetic. Also, as energy decreases from left to right, the frequency of the wave also decreases. But the wavelength increases or becomes longer.10. What is the IUPAC name of this compound? CH3 -CH2-C =C-CH3
Answer:
2-pentene or pent-2-ene
Which equation correctly describes the dissociation of sodium sulfate into ions in an aqueous media?
a. Na2SO4(aq) → 2Na+(aq) + SO42-(aq)
b. Na2SO4(aq) → 2Na+(aq) + S6+ (aq) + 4O2-(aq)
c. Na2SO4(aq) → Na2+(aq) + SO42-(aq)
d. Na2SO4(aq) → Na2S(aq) + 2 O2(g)
Na₂SO₄ (aq) → 2Na⁺ (aq) + SO4²⁻ (aq) correctly describes the dissociation of sodium sulfate into ions in an aqueous media
What is the dissociation reaction?Dissociation reactions are those reactions in which a molecule dissociates into their constitute ions.
In the question, dissociation of sodium sulfate takes place as follow:
Na₂SO₄ (aq) → 2Na⁺ (aq) + SO4²⁻ (aq)
Above reaction shows the dissociation of Na₂SO₄ where in the right side sodium ion is present in the +1 oxidation state and sulfate ion is present in the -2 oxidation state.
Hence, option (a) is correctly describes the dissociation.
To learn more about dissociation reaction, visit the below link:
https://brainly.com/question/18652437
If you use a hammer to weather a piece of chalk is it physical or chemical weathering and how do you know?