Answer:
II. 0.10 M HF + 0.10 M NaF.
Explanation:
A buffer system may be formed in one of two ways:
A weak acid and its conjugate base.A weak base and its conjugate acid.Which of the following mixtures could be considered a buffer?
I. 0.10 M HCl + 0.10 M NaCl. No, because HCl is a strong acid.
II. 0.10 M HF + 0.10 M NaF. Yes, since HF is a weak acid and F⁻ (coming from NaF) is its conjugate base.
III. 0.10 M HBr + 0.10 M NaBr. No, because HBr is a strong acid.
Question 10 of 23
Which characteristic makes a digital signal more useful than an analog signal
for storing information?
A. A digital signal includes a spectrum of colors.
B. A digital signal is more difficult to copy.
C. A digital signal cannot be heard by humans.
O D. A digital signal moves between a discrete number of values.
Answer: O D. A digital signal moves between a discrete number of values.
Explanation:
The digital signals are considered more reliable over the analog signals as they encode the information in a coded form. The bits or samples of the data are transmitted and converted into digital and numerical value. The stream of encoded data is in the form of continuous data at regular time intervals. It provides information in waveform and the data is in compact form. The data is in the form of binary bits 0 and 1 so greater the number of bits greater will be the greater will be the resolution of the information.
Atoms in the same PERIOD have the same...
A. Number of energy levels
B. Size
C. Temperature
D. Reactivity
Answer:
A. Number of energy levels
A strong acid, such as hydrochloric acid cannot be poured down a sink because it will react and dissolve the metal in the pipes. Yet a strong base, commonly found in drain cleaner, can be poured down a sink. A strong acid can be neutralized with a strong base, creating a salty water solution. What will happen when 10.0 g of hydrochloric acid were mixed with 10.5 grams of calcium hydroxide?
Answer:
15.2 grams of calcium chloride are produced and HCl is the limiting reactant.
Explanation:
Hello there!
In this case, according to the described scenario, it is possible to realize that the reaction between hydrochloric acid and calcium hydroxide is:
[tex]2HCl+Ca(OH)_2\rightarrow CaCl_2+2H_2O[/tex]
Whereas there is a 2:1 mole ratio of the acid to the base. In such a way, with the given masses, we can compute how much calcium chloride product is produced due to the chemical reaction via stoichiometry:
[tex]m_{CaCl_2}^{by HCl}=10.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molCaCl_2}{2molHCl} *\frac{110.98gCaCl_2}{1molCaCl_2} =15.2gCaCl_2\\\\m_{CaCl_2}^{by Ca(OH)_2}=10.5gHCl*\frac{1molCa(OH)_2}{74.09gCa(OH)_2}*\frac{1molCaCl_2}{1molCa(OH)_2} *\frac{110.98gCaCl_2}{1molCaCl_2} =15.7gCaCl_2[/tex]
Whereas we infer that the correct amount is 15.2 g since HCl is the limiting reactant as it produces the fewest grams of the desired product. Consequently, the calcium hydroxide is the excess reactant here.
Regards!
Which of the following combinations of quantum numbers is permissible?Question 23 options: n = 1, l = 2, ml = 0, ms = n = 4, l = 3, ml = 1, ms = n = 3, l = 3, ml = 1, ms = n = 2, l = 1, ml = –1, ms = 0 n = 4, l = 3, ml = 4, ms =
Answer: n= 4, , l= 3, [tex]m_l[/tex] = 1, permissible
Explanation:
Principle Quantum Numbers : It describes the size of the orbital and the energy level. It is represented by n. Where, n = 1,2,3,4....
Azimuthal Quantum Number : It describes the shape of the orbital. It is represented as 'l'. The value of l ranges from 0 to (n-1).For l = 0,1,2,3... the orbitals are s, p, d, f...
Magnetic Quantum Number : It describes the orientation of the orbitals. It is represented as [tex]m_l[/tex]. The value of this quantum number ranges from [tex](-l\text{ to }+l).[/tex]
Spin Quantum number : It describes the direction of electron spin. This is represented as [tex]m_s[/tex]. The value of this is [tex]+\frac{1}{2}[/tex] for upward spin and [tex]-\frac{1}{2}[/tex] for downward spin.
a) n=1 , l= 2, [tex]m_l[/tex] = 0, not permissible as l can not greater than n.
b) n= 4, , l= 3, [tex]m_l[/tex] = 1, permissible
c) n= 3, l= 3, [tex]m_l[/tex] = 1, not permissible as l can not equal than n.
d) n= 4 , l= 3, [tex]m_l[/tex] = 4, not permissible as [tex]m_l[/tex] can not greater than l.
An organic compound which has the empirical formula CHO has an approximate
molar mass of 145 g/mol. What is its probable molecular formula?
Answer:
Molecular formula => C₅H₅O₅
Explanation:
From the question given above, the following data were obtained:
Empirical formula = CHO
molar mass of compound = 145 g/mol
Molecular formula =?
The molecular formula of the compound can be obtained as follow:
Molecular formula = Empirical formula × n
Molecular formula = [CHO]ₙ
[CHO]ₙ = 145
[12 + 1 + 16]n = 145
29n = 145
Divide both side by 29
n = 145 / 29
n = 5
Molecular formula = [CHO]ₙ
Molecular formula = [CHO]₅
Molecular formula => C₅H₅O₅
4.00 g of O2 gas are in a sealed, 2.00 L gas canister at 22.0 °C what is the pressure inside this container (in atm)?
Answer:
1.51448 atms
Explanation:
A change in velocity can occur without a change in speed *
A: True
B: False?
Answer: True
Explanation: For example, changing direction can change velocity
how to calculate relative abundance of copper isotopes
Answer: Atomic mass (Cu) = (x)(63.0 amu) + (1 – x)(65.0 amu) = 63.5 amu 63.0x + 65 – 65.0x = 63.5 –2x = –1.5 x = 0.75 The percent abundance of each isotope is 75.0 % (Cu-63) and 25.0 % (Cu-65).
Explanation: As you know, the average atomic mass of an element is determined by taking the weighted average of the atomic masses of its naturally occurring isotopes.
Simply put, an element's naturally occurring isotopes will contribute to the average atomic mass of the element proportionally to their abundance.
Using current genetic engineering techniques can provide potential benefits for parents, including
A.
eliminating all genetic diseases from their child.
B.
conceiving a child who is a bone marrow match to a living child.
C.
cloning a parent to produce a child identical to the parent.
D.
producing only children with blonde hair.
Answer:
B. Conceiving a child who is a bone marrow match to a living child.
Explanation:
I don't know it just is.
A sample of chlorine gas has a volume of 0.30 L at 273 K and 1 atm pressure. What temperature (in ∘C) would be required to increase the volume to 1.0 L ?
Answer:
[tex]T_2=637\°C[/tex]
Explanation:
Hello there!
In this case, considering this problem as pressure constant, since the change is exhibited in temperature and volume only, it is possible for us to use the Charles' law as shown below:
[tex]\frac{V_2}{T_2}=\frac{V_1}{T_1}[/tex]
Thus, by solving for the final temperature, we obtain:
[tex]T_2=\frac{T_1V_2}{V_1}\\\\T_2=\frac{273K*1L}{0.30L}\\\\T_2=910K-273\\\\T_2=637\°C[/tex]
Best regards!
The elemental composition of propane gas (C3H8) is 81.68% C and 18.32% H by mass. What is the maximum amount of C3H8 in grams that can be formed from 160.0 g C and 160.0 g H
Molar mass of C3H8 = C 3 (12.01 g/mol) = 36.03 (g/mol)
H 8 (1.008 g/mol) = 8.064 (g/mol)
44.09 (g/mol)
74.6 g propane x 1 mole propane x 6.022 x 10
23
molecules
44.09 g propane 1 mole propane
= 1.02 x 10
24 molecules propane
A student in the lab accidentally poured 45 mL of water into a graduated cylinder containing 15 mL of 3.0 M HCL. What is the concentration of the new solution?
Answer:
The correct approach is "1 M".
Explanation:
The given values are:
Volume of HCL,
V₁ = 45 ml
In prepared solution,
V₂ = 15 ml
Concentration,
C₁ = ?
C₂ = 3.0 M
As we know,
⇒ [tex]V_1C_1=V_2C_2[/tex]
or,
⇒ [tex]C_1=\frac{V_2C_2}{V_1}[/tex]
On substituting the values, we get
⇒ [tex]=\frac{15\times 3}{45}[/tex]
⇒ [tex]=\frac{45}{45}[/tex]
⇒ [tex]=1 \ M[/tex]
How many grams are in 3.5 moles of H2O?
Answer:
Hi
Explanation:
We assume you are converting between moles H2O and gram. You can view more details on each measurement unit: molecular weight of H2O or grams This compound is also known as Water or Dihydrogen Monoxide. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles H2O, or 18.01528 grams.
1 mole is equal to 6.023 × 10 ²³ molecules. 63 grams are in 3.5 moles of H2O.
What do you mean by mole ?The term mole is defined as the amount of substance of a system which contains as many elementary entities.
One mole of any substance is equal to 6.023 × 10²³ units of that substance such as atoms, molecules, or ions. The number 6.023 × 10²³ is called as Avogadro's number or Avogadro's constant.
The mole concept can be used to convert between mass and number of particles.
We expect you are converting between moles H2O and gram. The molecular weight of H2O or gram's This compound is also known as Water or Dihydrogen Monoxide. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles H2O, or 18.01528 grams.
Thus, 63 grams are in 3.5 moles of H2O.
To learn more about the mole, follow the link;
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A mole equals 6.02 x 10^23 . Answer these questions below.
1. How many ants are in 1.25 moles of ants?
2. How many moles of pencils are in 4.92 * 10^26 pencils?
3. How many molecules are in 0.26 moles of molecules?
4. How many moles of molecules are in 3.46 * 10^19 molecules?
5. 5.3 * 10^20 atoms are equal to how many moles of atoms?
6. 0.11 moles of atoms are equal to how many atoms?
Answer:
1. 1.25 mol ants x 6.02*10^23 ants/1 mol ants = 7.53*10^23 ants
2. 4.92*10^26 pencils x 1 mol pencils/6.02*10^23 pencils = 817 mol pencils
3. 0.26 mol molecules x 6.02*10^23 molecules/1 mol molecules = 1.6*10^23 molecules
4. 3.46*10^19 molecules x 1 mol molecules/6.02*10^23 molecules = 5.75*10^-5 mol molecules
5. 5.3*10^20 atoms x 1 mol atoms/6.02*10^23 atoms = 8.8 mol atoms
6. 0.11 mol atoms x 6.02*10^23 atoms/1 mol atoms = 6.6*10^22 atoms
I would suggest looking into "dimensional analysis" for help with this type of material. Dimensional analysis will stick with you all throughout chemistry, so picking it up will be extremely beneficial.
What is one way humans can preserve biodiversity
Answer:
Reducing the amount of water you use, by having a 5-minute shower or not running the water when washing up the dishes, can help protect vital wetlands. Plant scientists are also working to help conserve by developing crop varieties that use less water.
Explanation:
Answer:
1. Most of the endangered organisms may represent a source of income.
2. The conservation or preservation may conflict with morals.
3. The role of the species or organisms might not be understood.
Explanation:
Biodiversity simply means the amount or number of living organisms that exist in the world.
The practice of protecting these existing living organisms for specific known purposes is regarded as the preservation or conservation of biodiversity.
This process or practice of preserving biodiversity is important to meet most of the human needs, such as generating income, source of food and fuel among others.
By examining data from distant stars, astronomers can determine
if a star is moving away from or toward Earth. Which of the
following pieces of data would be most helpful in determining
the motion of a star?
A The star gives off blue-white light.
B
The star gives off mainly radio waves and X-rays.
C
The light spectrum given off by the star is shifted toward the
red end.
.
D
The surface temperature of the star is approximately 10,000°
Celsius.
Answer:
The answer is A ahahahha
Explanation:
Because it just is
125.0 mL of 2.00 M NaCl solution is diluted to a concentration of 1.50 M. How many mL of water was added to the original volume? (Hint: must find V2 first) 1
166.7 ml
30.9 mL
41.7 ml
292 mL
(no links and please show work)
Answer:
Option A
Explanation:
As we know
C1V1 = C2V2
C1 = concentration of solution before dilution
V1 = Volume of solution before dilution
C2 = concentration of solution after dilution
V2 = Volume of solution after dilution
Substituting the given values in above equation, we get -
125 mL * 2.00 M = X mL * 1.50 M
X mL = 125 mL * 2.00 M / 1.50 M
X = 167 mL
Hence, option A is correct
A solution contains 1.817 mg of CoSO4 (155.0 grams/mole) per mL. Calculate the volume (in mL) of 0.009795 M Zn2 needed to titrate the excess complexing reagent after the addition of 70.00 mL of 0.009005 M EDTA to a 20.00 mL aliquot of the Co2 solution.
Answer:
85.952 ml [tex]Zn^2^+[/tex] needed to titrate the excess complexing reagent .
Explanation:
Lets calculate
After addition of 80 ml of EDTA the solution becomes = 20 + 70 = 90 ml
As the number of moles of [tex]CoSO_4[/tex] =[tex]\frac{Given mass }{molar mass}[/tex]
=[tex]\frac{1.817}{155}[/tex]
=0.01172
Molarity = [tex]\frac{no. of moles}{volume of solution}[/tex]
=[tex]\frac{0.01172}{20}[/tex]
=0.000586 moles
Excess of EDTA = concentration of EDTA - concentration of CoSO4
= 0.009005 - 0.000586
= 0.008419 M
As M1V1 ( Excess of EDTA ) = M2V2 [tex](Zn^2^+)[/tex]
[tex]0.008419\times100ml=0.009795\times V2[/tex]
[tex]V2=\frac{0.008419\times100}{0.009795}[/tex]
V2 =85.952 ml
Therefore , 85.952 ml [tex]Zn^2^+[/tex] needed to titrate the excess complexing reagent .
Where are electrons found in an atom?
Answer:
outside the nucleus
Explanation:
For any molecule at the surface the resulting surrounding forces equal zero
True
False
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It took 14.50 mL of 0.455M NaOH to fully neutralize 12.0mL of HCl. What is the concentration of the HCl?
HCl + NaOH \rightarrow→ NaCl + H2O
Answer:
0.550 M HCl
Explanation:
M1V1 = M2V2
M1 = 0.455 M NaOH
V1 = 14.50 mL NaOH
M2 = ?
V2 = 12.0 mL HCl
Solve for M2 --> M2 = M1V1/V2
M2 = (0.455 M)(14.50 mL) / (12.0 mL) = 0.550 M HCl
Answer:
The appropriate answer is "0.549 M".
Explanation:
The given values are:
N₁ = 14.50 mL
V₁ = 0.455 M
N₂ = 12 mL
Let
V₂ = C = ?
As we know,
⇒ [tex]N_1\times V_1=N_2\times V_2[/tex]
On substituting the values, we get
⇒ [tex]14.50\times 0.455 = 12\times C[/tex]
⇒ [tex]6.5975=12\times C[/tex]
⇒ [tex]C=\frac{6.5975}{12}[/tex]
⇒ [tex]=0.549 \ M[/tex]
Which layer of the Earth includes the crust? a atmosphere b hydrosphere c asthenosphere d lithosphere
Answer:
D
Explanation:
Hope that helps :)
are two double bonds in
uble dash.
:0=C=O
NO2-
Answer:
Yes
Explanation:
There are in double dash :) ( = )
Answer:
yes
Explanation:
Because the double dash shows a double bond it simply means that two electrons from each atom are being shared
calorimetry and specific heat lab report can someone please write this for me
If anyone still needed help on this, someone wrote out the student table on brainly.com, look up Lab: Calorimetry and Specific Heat.
The page should say something along the lines of please Please i need it Lab: Calorimetry and Specific Heat
This one should help you a lot more. Good luck.
Answer:
If anyone still needed help on this, someone wrote out the student table on brainly.com, look up Lab: Calorimetry and Specific Heat.
The page should say something along the lines of please Please i need it Lab: Calorimetry and Specific Heat
This one should help you a lot more. Good luck.
Explanation:
Explain what you think controls a material’s porosity
The primary porosity of a sediment or rock consists of the spaces between the grains that make up that material. The more tightly packed the grains are, the lower the porosity.
How many moles of hydrogen
are in 3.06 x 10^-3 g of glycine C2H5NO2
Answer:
2.04x10⁻⁴ mol
Explanation:
First we convert 3.06x10⁻³ grams of glycine into moles of glycine, using its molar mass:
3.06x10⁻³ g ÷ 75 g/mol = 4.08x10⁻⁵ mol C₂H₅NO₂In order to calculate the number of hydrogen moles, we multiply the number of glycine moles by 5, as there are 5 hydrogen moles per glycine mol:
4.08x10⁻⁵ mol C₂H₅NO₂ * 5 = 2.04x10⁻⁴ mol HTwo elevators carry five passengers to the fifth floor. However, the elevators do not do the same work. Choose the best factor for
determining the amount of work the elevators did.
A.the speed of the elevator
B.the weight of the passengers
C.the number of buttons pressed
Will mark brainlist pls help!
Answer:
B the weight of the passengers
Data Collection
Mass of the original sample of mixture (g) 1.558
Mass of recovered naphthalene (g) 0.483
Mass of recovered 3-nitroaniline (g) 0.499
Mass of recovered benzoic acid (g) 0.467
Calculations:
a. % by mass of naphthalene in original sample.
b. % by mass of 3-nitroaniline in original sample.
c. % by mass of benzoic acid in original sample.
d. total percent recovered.
Answer:
For a): The mass percent of naphthalene in the original sample is 31.00 %.
For b): The mass percent of 3-nitroaniline in the original sample is 32.03 %.
For c): The mass percent of benzoic acid in the original sample is 29.97 %.
For d): The total percent recovered is 93.00 %.
Explanation:
Percentage by mass is defined as the ratio of the mass of a substance to the mass of the solution multiplied by 100. The formula used for this is:
[tex]\text{Percent by mass}=\frac{\text{Mass of substance}}{\text{Mass of a solution}} \times 100[/tex] ......(1)
a):
Mass of naphthalene = 0.483 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\%\text{ mass of naphthalene}=\frac{0.483 g}{1.558}\times 100\\\\\%\text{ mass of naphthalene}=31.00 \%[/tex]
b):
Mass of 3-nitroaniline = 0.499 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\%\text{ mass of 3-nitroaniline}=\frac{0.499 g}{1.558}\times 100\\\\\%\text{ mass of 3-nitroaniline}=32.03 \%[/tex]
c):
Mass of benzoic acid = 0.467 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\%\text{ mass of benzoic acid}=\frac{0.467 g}{1.558}\times 100\\\\\%\text{ mass of benozic acid}=29.97 \%[/tex]
d):
Total mass recovered = [0.483 + 0.499 + 0.467] = 1.449 g
Mass of the sample = 1.558 g
Plugging values in equation 1:
[tex]\text{Total percent recovered}=\frac{1.449 g}{1.558}\times 100\\\\\text{Total percent recovered}=93.00\%[/tex]
List four reasons why the temperature of a flame is lower than the adiabatic flame temperature."
Answer:
substances is never entirely a one way
Explanation:
no possibility of obtaining complete combustion at hig
temperature.
always loss of heat from the temperature
its temperature is lower than the constant volume process because some of the energy is utilized to change the volume of the system
Four reasons why the temperature of flame is lower than adiabatic flame temperature is that there is no possibility of obtaining complete combustion at high temperature due to high thermal energy.There is always loss of heat from temperature,its temperature is lower than constant volume process because some of energy is utilized to change the volume of the system.
What is thermal energy?Thermal energy is defined as a type of energy which is contained within a system which is responsible for temperature rise.Heat is a type of thermal energy.It is concerned with the first law of thermodynamics.
Thermal energy arises from friction and drag.It includes the internal energy or enthalpy of a body of matter and radiation.It is related to internal energy and heat .It arises when a substance whose molecules or atoms are vibrating faster.
These vibrating molecules and atoms collide and as a result of which heat is generated in a substance , more the collision of particles , higher is the thermal energy.
Learn more about thermal energy,here:
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What are the 5 properties of muscles