Determine whether or not each combination of substances can be used to create a buffer. 0.1 M HCl, 0.1 M KCl Choose... 0.1 M HNO2, 0.05 M NaOH Choose... 0.05 M HNO2, 0.05 M NaNO2 Choose... 1 M Na2HPO4, 1 M NaH2PO4 Choose... 0.4 M KOH, 0.2 M NaOH Choose...
Answer:
Explanation:
A buffer solution is a mixture of two substances consisting of a weak acid and it's conjugate base. A buffer solution resists a change in pH.
From the description above, we can denote that a buffer must consist of a weak acid and it's conjugate base/salt.
The first option has a strong acid (HCl) and hence the solution cannot form a buffer.
The second option has a strong base (NaOH) which is not a conjugate base of HNO₂. Thus the solution cannot form a buffer.
The third option has HNO₂ which is a weak acid and NaNO₂ which is it's salt, hence it can form a buffer.
The fourth option has NaH₂PO₄ which will act as an acid while Na₂HPO₄ will act as it's salt to produce a phosphate buffer.
The fifth option has two strong bases hence cannot form a buffer
The combination which serves as a buffer solution is 0.05 M HNO2, 0.05 M NaNO2.
A buffer solution is a solution that is made up of a weak acid and its conjugate base. It is also a solution of a weak base and its conjugate acid. We need to look at the options listed and find out the option that is composed of a weak acid and its conjugate base or a weak base and its conjugate acid.
The combination which serves as a buffer solution is 0.05 M HNO2, 0.05 M NaNO2. HNO2 is a weak acid and NO2- is its conjugate base hence they compose a buffer solution.
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the gravitational energy of a golf ball at differnt heights is shown in the table below which graph best represent the relationship between the ball's gravitational energy and its height above the ground. I need helplease
Answer:
A because it's uniform
Answer:
a
Explanation:
The length is 3 inches, the width It’s 4 inches, the height is 5 inches. What is the volume
Answer:
answer is 60 inches ^3.
multiply!
Shelly wants to find the speed that her dog can run. What should Shelly do?
A. measure the distance the dog runs
B. measure the time the dog runs
C. measure the size of the dog and the distance it runs
D. measure the time it takes for the dog to run a certain distance
Answer:A
Explanation:
Mass = 25g, Volume = 5mL. What is the density? *
Answer:
5ml
Explanation:
m/v
25/5=5
means 25÷5=5
Give two examples in which the host is harmed.
Answer:
lice, mosquito
Explanation:
both are examples of parasitism
edit: wait nvm i thought this was bio
Which of the following is a form of mechanical energy?
Group of answer choices
Thermal energy
Kinetic energy
Chemical energy
Nuclear energy
Answer:
thermal energy
Explanation:
due to the heat
Answer:
Answer:kinetic energy
Explanation:
Mechanical energy can be either kinetic energy (energy of motion) or potential energy (stored energy of position).
You have 0.14 moles of sodium chloride (NaCl). How many grams do you have? ( 1 mole of NaCl = 58 grams NaCl) *
0.14 grams NaCl
3.2 grams NaCl
5.9 grams NaCl
8.12 grams NaCl
Answer:
Option D is correct = 8.12 grams of NaCl
Explanation:
Given data:
Moles of sodium chloride = 0.14 mol
Mass of sodium chloride = ?
Solution:
Formula:
Number of moles = mass of NaCl / Molar mass of NaCl
Molar mass of NaCl = 58 g/mol
Now we will put the values in formula.
0.14 mol = Mass of NaCl / 58 g/mol
Mass of NaCl = 0.14 mol × 58 g/mol
Mass of NaCl = 8.12 g of NaCl
Thus, 0.14 moles of NaCl contain 8.12 g of NaCl.
10. Some animals only have cell.
Answer:
no animals have cells
Explanation:
cells are a theory made up by old scientists
Water brought to the surface from deeper water is warm and nutrient-poor. *
Answer:
You made a statement not a question
Explanation:
A. Calculations for the Determination of Ammonium Chloride The data from the data entry portion of the report has been copied into this section of the report for your convenience. Use the data to make the necessary calculations.
(1) Mass of evaporating dish on #1: 38.646
(2) Mass of evaporating dish and original sample (a): 39 591
(3) Mass of evaporating dish after subliming Nha (g) 39.4750
B. Calculations for the Determination of Sodium Chloride 14 Mass of evaporating dish #2: IS Mass of watch glass (a):
(1) Mass of evaporating dish #2 38700 g
(2) Mass of watch glass. 28 299 g
(3) Mass of evaporating dish #2, watch glass and NaCl(a): 67,355
C. Calculations for the Determination of Sand
Mass of evaporating dish #1: 38.645
Mass of evaporating dish and SiO2 (g) 39.405
D. Summary
Mass of original sample (0)
Experimental mass recovered (NH4Cl + NaCl + S107)
Differences in these weights (g) (use the absolute value of the difference)
recovery of matter
Select a reasonable explanation to account for the differences. There may be more than one possible reason that makes sense, just select one of them.
A. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher.
B. It is possible not all of the water was evaporated from the sand, causing the recovered mass to be lower.
C. While drying the NaCl, the liquid bolled and some splattered out of the evaporating dish, causing the recovered mass to be lower.
D. While drying the Naci, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be higher.
E. There was no difference in recovered and original mass, so there is no difference to account for.
Answer:
A
Explanation:
Considering question A
Mass of original sample is [tex]m_o = 0.945 \ g [/tex]
Mass of NH4Cl is [tex]m_n = 0.116 \ g [/tex]
Percent of NH4Cl is [tex]k = 12.275 \% [/tex]
B
Mass of NaCl [tex]m_k = 0.359 \ g [/tex]
C
Mass of SiO2 [tex]m_e = 0.46[/tex]
D
Mass of original sample [tex]m_o = 0.945 \ g [/tex]
Differences in these weights (g) (use the absolute value of the difference)
recovery of matter [tex]G = 0.01 \ g [/tex]
The correct option is C
From the question we are told that
The mass of evaporating dish on #1 is [tex]m_1 = 38.646 \ g[/tex]
The mass of evaporating dish and original sample [tex]m_2 = 39 591 \ g[/tex]
The mass of evaporating dish after subliming [tex]NH_4Cl [/tex] is [tex]m_3 = 39.4750 \ g[/tex]
Generally the mass of the original sample is mathematically represented as
[tex]m_o = m_2 - m_1[/tex]
=> [tex]m_o = 39 591 - 38.646 [/tex]
=> [tex]m_o = 0.945 \ g [/tex]
Generally the mass of [tex]NH_4Cl[/tex] is mathematically represented as
[tex]m_n = m_2 - m_3[/tex]
=> [tex]m_n = 39 591 - 39.4750[/tex]
=> [tex]m_n = 0.116 \ g [/tex]
The Percent [tex]NaH_4 Cl (g)[/tex]
[tex]k = \frac{ m_n}{m_o} *100[/tex]
=> [tex]k = \frac{0.116 }{0.945} *100[/tex]
=> [tex]k = 12.275 \% [/tex]
Considering question B
The mass of evaporating dish #2 is [tex]m_g = 38700\ g[/tex]
The mass of watch glass is [tex]m_a = 28 299 \ g[/tex]
The mass of evaporating dish #2, watch glass and NaCl [tex]m_b = 67,355 \ g[/tex]
Generally the mass of NaCl is
[tex]m_k = m_b -[m_g + m_a][/tex]
=> [tex]m_k = 67,355 -[38700 + 28 299][/tex]
=> [tex]m_k = 0.359 \ g [/tex]
Considering question C
The mass of evaporating dish is [tex] m_p= 38.645[/tex]
The mass of evaporating dish and SiO2 [tex]m_s = 39.105 \ g[/tex]
Generally the mass of SiO2 is mathematically represented as
[tex]m_e = 39.105 - 38.645[/tex]
=> [tex]m_e = 0.46[/tex]
Considering D
The mass of the original sample is [tex]m_o = 0.945 \ g[/tex]
Generally the experimental mass recovered (NH_4Cl,NaCl, SiO2 ) is mathematically evaluated as
[tex]M =0.116 + 0.46 + 0.359[/tex]
[tex]M = 0.935 \ g [/tex]
Generally the differences in these weights (g) of recovery of matter is mathematically represented as.
[tex]G =0.945- 0.935 [/tex]
=> [tex]G = 0.01 \ g [/tex]
While drying the NaCl, the liquid boiled and some splattered out of the evaporating dish, causing the recovered mass to be lower.
Which explains one reason evaporation can be used to separate a mixture? The desired component has a higher boiling point than the other components. The desired component has a different density from the other components. The mixture is a solution that contains a substance that will crystallize out. The desired component has the smallest particles in the mixture.
Answer: The component has a higher boiling point
Explanation:
Answer:
A. The desired component has a higher boiling point than the other components.
Explanation:
This is on the unit test
Question 2
1.5 moles of copper (Cu) consists of how many atoms of copper?
A mixture of 80.0 g of Cr2O3 and 8.00 g of C is used to produce elemental Cr by the reaction below:
Cr2O3 + 3 C ----> 2 Cr + 3 CO
a) What is the theoretical yield of Cr that can be obtained from the reaction mixture?
b) The actual yield is 21.7 g Cr. What is the percent yield for the reaction?
Answer:
A is 90g. B is 34.7g
Explanation:
The amount of matter in an object
A Mass
B weight
C non contact force
D friction
E net force
Answer:
A)Mass
Explanation:
Mass measure the amount of matter
If I add 2 grams of sugar to 50 grams of water what should the mass of my
mixture be?
Answer:
[tex]m_{mixture}=52g[/tex]
Explanation:
Hello.
In this case, since your mixture is composed by sugar and water, its mass turns out:
[tex]m_{mixture}=m_{sugar}+m_{water}[/tex]
Whereas the mass of sugar is 2 g and the mass of water is 50 g, therefore, the result is:
[tex]m_{mixture}=2g+50g\\\\m_{mixture}=52g[/tex]
Best regards.
Can someone help me pls
Answer:
50 years
12.5 g
2.5 g
Explanation:
The half-life is the time it takes for the sample to become half of the original. At 0 years, none of the sample has decayed. At 50 years, half of the sample has decayed. This means that the half-life is 50 years.
If you look at the diagram, at 150 years, you will have 1/8 of the original amount. If you start with 100 g, you will have 12.5 g after 150 years.
100/8 = 12.5
Looking at the diagram, you can see that at 100 years, you will have 1/4 of the original amount. If you start with 10 g, you will have 2.5 g after 100 years.
10/4 = 2.5
What charge does Co have in Cobalt (III) Chloride?
Answer:
+3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). . In this compound, the cobalt atoms have a formal charge of +3.
Explanation:
Answer:
+3
Explanation:
(the roman numerals tells all)
can a mixture be formed into a compound?
A mixture cannot be formed in to a compound as formation of mixtures is accompanied by physical changes and formation of compounds is accompanied by chemical changes.
What is a compound?
Compound is defined as a chemical substance made up of identical molecules containing atoms from more than one type of chemical element.
Molecule consisting atoms of only one element is not called compound.It is transformed into new substances during chemical reactions. There are four major types of compounds depending on chemical bonding present in them.They are:
1)Molecular compounds where in atoms are joined by covalent bonds.
2) ionic compounds where atoms are joined by ionic bond.
3)Inter-metallic compounds where atoms are held by metallic bonds
4) co-ordination complexes where atoms are held by co-ordinate bonds.
They have a unique chemical structure held together by chemical bonds. Compounds have different properties as those of elements because when a compound is formed the properties of the substance are totally altered.
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A 5 kg ball is traveling at the same speed as a 10 kg ball. Compared to with 5 kg ball, the 10 kg ball has (2 points)
Answer: twice the momentum
Explanation:
All waves on the electromagnetic spectrum travel...
A
at different speed depending on their energy
B
at the speed of light (3x108 m/s)
C at different speeds depending on their wavelength & frequency
at their own pace, because they can't be bothered
Answer:B
at the speed of light (3x108 m/s)
Explanation: because it use quizlet
Why can some atoms , such as helium , neon , and argon consist of a collection of individual atoms that move about independently of one another and all other atoms consists of two or more atoms joined by strong forces called chemical bonds ?
Answer:
Noble gases already have a completed Octet structure hence they are stable.
Explanation:
One basic reason for chemical reaction is that individual atoms seek to attain the stable Octet, that means, to have eight electrons on their outermost shell.
The noble gases are stable since they have already achieved this stable octet structure.
Having already filled electron shells, noble gases hardly participate in chemical bonding but often exist in the gas phase as isolated atoms.
The noble gases have been present as an individual atom due to the complete outer valence shell.
In an atom, the presence of valence electrons has been the representation of the reactivity of the atom.
The atoms tend to complete the outermost octet and become stable. In order to be stabilized, the elements form chemical bonds with the same element and have been present in the diatomic form.
However, with noble gases such as Neon, Helium the outer valence shell has been complete, they have been present as individual atoms with less reactivity.
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((Reuploaded)) Do all structural formulas for each amino acid have an amino group?
Answer:
All of the proteins on the face of the earth are made up of the same 20 amino acids. Linked together in long chains called polypeptides, amino acids are the building blocks for the vast assortment of proteins found in all living cells. All amino acids have the same basic structure
WILL GIVE BRAINLYEST The following element has how many protons?
silicon
14
SI 28.086
Question 9 options:
14
56
7
28
Answer:
14.
Explanation:
Answer:
14 hope this helps
Explanation:
Atomic Mass-Atomic Number my guy
The following question was posed on an exam:
An unknown non-metal element (Q) forms two gaseous fluorides of unknown molecular formula. A 3.2g sample of Q reacts with fluorine to form 10.8 g of the unknown fluoride A. A 6.4 g sample of Q reacts with fluorine to form 29.2 g of unknown fluoride B. Using these data only, demonstrate by calculation and explanation that these unknown compounds obey the Low of Multiple Proportions.
A student responded with the following answer: The Law of Multiple Proportions states that when two elements form two or more compounds, the ratios of the masses of the elements between the two compounds are in o simple whole number ratio. So, looking of the data above, we see that the ratio of the moss of element Q in compound A to the mass of element Q in compound B is, which is a simple whole number ratio. This demonstrates that these compounds obey the low of Multiple Proportions. Assess the accuracy of the students answer. In your assessment, you must determine what information is correct or Incorrect, provide the correct information where needed, explain whether the reasoning is logical or not, and provide logical reasoning where needed.
Answer:
The answer given by the student is not totally correct.
Explanation:
Law of multiple proportions states that an element Q will react with different volume of Fluorine to produce two non-similar compounds. Hence, the ratio of the masses(Fluorine only) needs to be an absolute reduced value.
Given that:
3.2 g of a sample of Q reacts with Fluorine to form 10.8 g of the unknown fluoride A.
This means the mass of Fluorine present in the compound = 10.8 g - 3.2 g = 7.6 g
Thus, 3.2 g of a sample of Q reacts with 7.6 g of Fluorine.
Also, 6.4 g sample of Q reacts with Fluorine to form 29.2 g of unknown fluoride B.
If we divide the samples by (2), we have 3.2 g sample of Q reacting with Fluorine to form 14.6 g of unknown fluoride B.
This means the mass of Fluorine present in the compound = 14.6 g - 3.2 g = 11.4 g
Thus, 3.2 g Q reacted here with 11.4 g fluorine.
Hence, 11.4/7.6 = 1.5 = 3/2
This above therefore satisfies the law of multiple proportions.
This is not aligned with what the student did, what the student did was to relate the amount of Q used to make A and B. Suppose, we start with twice amount of Q, the ratio would have been smaller(i.e. the ratio of Q).
So, this doesn't relate to the law of multiple proportions.
The law of multiple proportions is specifically concerned with the mass of the element rather than Q that can react with Q. Therefore, there is more reason to relate the two samples of equal masses of Q that react with different masses of Fluorine. The ratios of Fluorine will then be small whole numbers.
Typical frequencies for several types of electromagnetic radiation are given below. Calculate the energy of each type of radiation.
a. A gamma ray: ν = 1.64 ✕ 10^20 s^−1
b. A microwave: ν = 4.95 ✕ 10^10 s^−1
c. An AM radio wave: ν = 2.00 ✕ 10^6 s^−1
Explanation:
The energy of electromagnetic radiation is given by :
[tex]E=h\nu[/tex]
Where, h is the Planck's constant
(a) A gamma ray, [tex]\nu = 1.64\times 10^{20}\ Hz[/tex]
Energy,
[tex]E=6.63\times 10^{-34}\times 1.64\times 10^{20}\\E=1.08\times 10^{-13}\ J[/tex]
(b) A microwave, [tex]\nu = 4.95\times 10^{10}\ Hz[/tex]
Energy,
[tex]E=6.63\times 10^{-34}\times 4.95\times 10^{10}\\E=3.28\times 10^{-23}\ J[/tex]
(c) A AM radio wave, [tex]\nu = 2\times 10^{6}\ Hz[/tex]
Energy,
[tex]E=6.63\times 10^{-34}\times 2\times 10^{6}\\E=1.32\times 10^{-27}\ J[/tex]
Therefore, this is the required solution.
how many moles of chlorine gas is contained in 4.81x10^24 molecules
Answer:
7.99 mol
Explanation:
Step 1: Given data
Molecules of chlorine gas: 4.81 × 10²⁴ molecules
Step 2: Calculate how many moles of chlorine gas corresponds to 4.81 × 10²⁴ molecules of chlorine gas
In order to convert molecules to moles, we will use Avogadro's number: there are 6.02 × 10²³ molecules of chlorine gas in 1 mole of molecules of chlorine gas.
4.81 × 10²⁴ molecules × (1 mol/6.02 × 10²³ molecules) = 7.99 mol
I tooktwo plants that like 3% NaCl environments and I put one in a 3M NaCl solution and a 0.6M NaCl solution. Describe what will happen to each plant. Hint: convert the molarity into percentag
Answer:
In the 3M NaCl solution, is plant will wilt and die due to loss of water from its cell as the solution is far too hypertonic.
In the 0.6M NaCl solution, this plant will thrive as the solution is a fairly 3% NaCl environment.
Explanation:
Molar mass of of NaCl = 58.5 g/mol, Density of water = 1 g/mL; 1 Litre = 1000 mL
3M or 3 mol/dm³ NaCl solution contains 3 moles of NaCl in 1 litre of solution.
3 moles of NaCl has a mass of 3 * 58.5 g = 175.5 g
Percentage solution = (175.7 g / 1000 g ) * 100 = 17.55% NaCl
0.6M or 0.6 mol/dm³ NaCl solution contains 0.6 moles of NaCl in 1 litre of solution.
0.6 moles of NaCl has a mass of 0.6 * 58.5 g = 35.1 g
Percentage solution = (35.1 g / 1000 g ) * 100 = 3.51% NaCl
In the 3M NaCl solution, is plant will wilt and die due to loss of water from its cell as the solution is far too hypertonic.
In the 0.6M NaCl solution, this plant will thrive as the solution is a fairly 3% NaCl environment.
This is how manganese appears in the periodic table.
What is the arrow is pointing to?
period symbol of manganese
isotope symbol of manganese
group symbol of manganese
atomic symbol of manganese
Answer: The atomic symbol of manganese or Aka D
Explanation: I did the test
Answer:
The atomic symbol of manganese or Aka D
Explanation:
Copper has a density of 8,96 g/cm2 The amount of 75,0 g of copper is added to 0,0500 litres of water in a graduated cylinder. The volume reading to which the water level in 118
cylinder will rise in mililitres is (a).
Answer:
Volume reading rise to 58.37 mL
Explanation:
Given data:
Density of copper = 8.96 g/cm³
Amount of copper = 75.0 g
Volume of water in cylinder = 0.0500 L
Volume rise = ?
Solution:
First of all we will calculate the volume of copper. The volume rise up is equal to the volume of copper.
Formula:
d = m/v
8.96 g/cm³ = 75.0 g/ v
v = 75.0 g / 8.96 g/cm³
v = 8.37 cm³
cm³ = mL
Volume of water = 0.0500 L × 1000 mL / 1L
Volume of water = 50 mL
Volume reading rise to = 50 mL + 8.37 mL
Volume reading rise to 58.37 mL.