Answer:
205mL of 0.140M KF solution
Explanation:
pH = 2.70 solution.
It is possible to obtain the pH of the buffer of HF-KF using the H-H equation:
pH = pKa + log [KF] / [HF]
Where pH is desire pH = 2.70
pKa is pKa of HF = 3.17
[KF] could be taken as moles of KF
And [HF] moles of HF: 400.0mL = 0.4L * (0.212mol/L) = 0.0848 moles of HF
Replacing:
2.70 = 3.17 + log [KF] / [0.0848 moles HF]
-0.47 = log [KF] / [0.0848 moles HF]
0.3388 = [KF] / [0.0848 moles HF]
[KF] = 0.02873 moles of KF must be added.
In mL using concentration of KF (0.140M):
0.02873 moles KF * (1L / 0.140 mol) = 0.205L =
205mL of 0.140M KF solutionTrue or False: All temperatures used in the comparisons or calculations of gases must use the Kelvin temperature scale.
Answer:
True
Explanation:
I used my notes from class today. I could be wrong.
Which best describs the energy transformation in a battery powered flash light ?
a
Chemical, to electrical, to thermal, to radiant
b
nuclear, to electrical, to thermal, to radiant
c
Mechanical, to electrical, to Thermal, to radiant
d
Chemical, to electrical, to mechanical, to radiant
Answer:
I think it's C
Explanation:
Sorry if its wrong
Answer:
C
Explanation:
What is the pH value of distilled water?
Answer:
7
Explanation:
state Graham's law diffusion of gas mathematical expression ?
Answer:
Graham's law states that the rate of diffusion or of effusion of a gas is inversely proportional to the square root of its molecular weight
Explanation:
A 500.0-mL buffer solution is 0.100 M in HNO2 and 0.150 M in KNO2. Determine if each addition would exceed the capacity of the buffer to neutralize it.
a. 250 mg NaOH
b. 350 mg KOH
c. 125 g HBr
d. 1.35g Hl
Answer:
no one additions exceed the capacity of the buffer
Explanation:
given
Volume buffer = 500.0 mL = 0.5 L
mol HNO₂ = 0.5 L × 0.100 mol/L = 0.05 mol HNO₂
mol NO₂⁻ = 0.5 L × 0.150 mol/L = 0.075 mol NO₂⁻
solution
we know when any base more than 0.05 (HNO2) than exceed buffer capacity
and when any base more than 0.075 (KNO2) than exceed buffer capacity
when we add 250 mg NaOH (0.250 g)
than molar mass NaOH =40 g/mol
and mol NaOH = 0.250 g ÷ 40g/mol
mol NaOH = 0.00625 mol
0.00625 mol NaOH will be neutralized by 0.00625 mol HNO₂
so it would not exceed the capacity of the buffer.
and
when we add 350 mg KOH (0.350 g)
than molar mass KOH =56.10 g
and mol KOH = 0.350 g ÷ 56.10 g/mol
mol KOH = 0.0062 mol
here also capacity of the buffer will not be exceeded
and
now we add 1.25 g HBr
than molar mass HBr = 80.91 g/mol
and mol HBr = 1.25 g ÷ 80.91 g/mol
mol HBr = 0.015 mol
0.015 mol Hbr will neutralize 0.015 mol NO₂⁻
so the capacity will not be exceeded.
and
we add 1.35 g HI
molar mass HI = 127.91 g/mol
so mol HI = 1.35 g ÷ 127.91 g/mol
mol HI = 0.011 mol
capacity of the buffer will not be exceed
Scientists discover remains of wooden structures near a Celtic runes site. What kind of testing will indicate when the stones were moved into place by the Celts?
Carbon dating
Radioactive dating
Answer:
Carbon
Explanation:
Bc i got this question on my test
Answer:
A. Carbon dating
Explanation:
I took the test proof
You have two containers. The first container contains 22.99 grams of solid
sodium (Na). The second container contains 15.999 grams of Oxygen (O).
Which container has more moles of the indicated substance? *
Answer:
The sodium has more moles.
n(Na)=2.09 mole
n(O)=0.999 mole
How many formula units make up 20.6 g of magnesium chloride (MgCl2)?
Answer:The formula of magnesium chloride is MgCl2 . The molar mass of MgCl2 is (24.30 + 2 × 35.45) g/mol=95.20 g/mol .
Explanation:
Which problem that the most scientists believe is partly caused by carbon dioxide?
Answer:
Climate change
Explanation:
Climate change is primarily a problem of too much carbon dioxide (CO2) in the atmosphere. This carbon overload is caused mainly when we burn fossil fuels like coal, oil and gas or cut down and burn forests
SO3 is a covalent compound with no lone pairs on the central S atom. What's the structure of a molecule of SO3? Is an SO3 molecule polar or non-polar?
Question 14 options:
A)
Trigonal planar, non-polar
B)
Trigonal pyramidal, polar
C)
Trigonal planar, polar
D)
Trigonal pyramidal, non-polar
Answer:
A
Explanation:
it has non polar molecule, because it has the equal sharing of electrons, so equal repulsion from all sides. atoms are equally represented.
Answer:
Trigonal planar, non-polar
Explanation:
Nose color is an inherited trait in dogs. Two puppies from the same set of parents have different color noses. One puppy has a pink nose and one puppy has a black nose. How can puppies from the same set of parents have different color noses?
A.
The pink-nosed puppy and the black nosed puppy must not actually be related.
B.
The pink-nosed puppy and the black nosed puppy inherited different combinations of the genes for nose color from their parents.
C.
The pink-nosed puppy has a different number of chromosomes than the black nosed puppy.
D.
The pink nosed puppy and the black nosed puppy have different chromosomes for the two nose colors.
Answer:
I thin its B im not sure though
Explanation:
The puppies from the same set of parents have different color noses because the pink-nosed puppy and the black nosed puppy inherited different combinations of the genes for nose color from their parents. Thus, the correct option is B.
What is a gene?A gene is the unit of inheritance which is made up of DNA (deoxyribonucleic acid). Every person receives two copies or alleles of each gene which is inherited from each of the two parent.
Genes are made up of DNA, so each of the chromosome contains many different genes. Genes carry the information which determines the traits or characteristics that are passed on to their offspring or inherited from the parents.
The puppies from the same set of parents have different colored noses because pink-nosed puppy and the black nosed puppy inherited different combinations of the genes for nose color from their parents.
Therefore, the correct option is B.
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3. What is the pairing arrangement of the nitrogenous bases? _____________ pairs with __________ and ____________ pairs with ___________.
Answer:
Adenine pairs with thymine and guanine pairs with cytosine
WILL GIVE 50 POINTS AND BRAINLIEST
Plate Tectonics Lab Report
Instructions: In the Plate Tectonics lab you will investigate the interactions between continental and oceanic plates at convergent, divergent, and transform boundaries around the globe. Record your observations in the lab report below. You will submit your completed report.
Name and Title:
Include your name, instructor's name, date, and name of lab.
Objective(s):
In your own words, what was the purpose of this lab?
Hypothesis:
In this section, please include the if/then statements you developed during your lab activity for each location on the map. These statements reflect your predicted outcomes for the experiment.
Location One: Select two events that you predict will be observed. If I explore two continental plates at a convergent boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Two: Select three events that you predict will be observed. If I explore two continental plates at a divergent boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Three: Select three events that you predict will be observed. If I explore two continental plates at a transform boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Four: Select two events that you predict will be observed. If I explore two oceanic plates at a convergent boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Five: Select three events that you predict will be observed. If I explore two oceanic plates at a divergent boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Location Six: Select two events that you predict will be observed. If I explore two oceanic plates at a transform boundary, then I will observe:
earthquakes
faults
ocean formation
mountains
volcanoes
island chains
seafloor spreading
Procedure:
The procedures are listed in your virtual lab. You do not need to repeat them here. Please be sure to identify the test variable (independent variable), outcome variable (dependent variable).
Reminder: Test variable = the item you are changing or manipulating; Outcome variable = the item you are measuring
Test variable (independent variable):
Outcome variable (dependent variable):
Data:
Record the data from each location below.
Location Name Boundary Type
(C=Convergent, D=Divergent, or T=Transform) Year Observed
(5, 10, or 20 million years) Geologic Events Observed
(earthquakes, faults, ocean formation, mountains, volcanoes, island chains, seafloor spreading)
Location One
Himalayas 5 Event 1-
20 Event 2-
Location Two
East Africa 5 Event 1-
10 Event 2-
20 Event 3-
Location Three
San Andreas fault zone 5 Event 1-
10 Event 2-
20 Event 3-
Location Four
Aleutian Islands 5 Event 1-
20 Event 2-
Location Five
Mid-Atlantic Ridge 5 Event 1-
10 Event 2-
20 Event 3-
Location Six
Alpine Fault 5 Event 1-
20 Event 2-
Conclusion:
Your conclusion will include a summary of the lab results and an interpretation of the results. Please write in complete sentences.
What types of geological events or changes occur at divergent plate boundaries?
What types of geological events or changes occur at convergent plate boundaries?
What types of geological events or changes occur at transform plate boundaries?
Explain how these geological processes and interactions have changed Earth's surface through the years. Be sure to use evidence to support your answer.
Answer:
here are what i have so far, im doing this right now
Explanation:
Plate Tectonics Lab Report
Instructions: In the Plate Tectonic lab you will investigate the interactions between continental and oceanic plates at convergent, divergent, and transform boundaries around the globe. Record your observations in the lab report below. Y
Objective(s):
To look at interactions between continental and oceanic plates, etc.
Hypothesis:
In this section, please include the if/then statements you developed during your lab activity for each location on the map. These statements reflect your predicted outcomes for the experiment.
Location One: Select three events that you predict will be observed. If I explore two continental plates at a convergent boundary, then I will observe:
• earthquakes
• mountains
• volcanoes
Location Two: Select three events that you predict will be observed. If explore two continental plates at a divergent boundary, then I will observe:
• ocean formation
• volcanoes
• seafloor spreading
you will submit your completed report
ps; you might want to change up the objective.
A geological event is a brief, spatially diverse, dynamic and ongoing occurrence in the history of the Earth.
What is geological event?A geological event is a brief, spatially diverse, dynamic (diachronous), and ongoing occurrence in the history of the Earth that aids in the modification of the Earth system and the production of geological strata. The concept of event stratigraphy initially came up as a way to identify, analyse, and correlate how significant physical and biological events have affected the overall stratigraphical record.
Israel's Dead Sea basin Holocene sediments contain seismic activity. This can be considered a record of a geological event, an earthquake, that altered the strata. Geological events can occur over timescales of order of magnitude, from just a few seconds through millions of years, as well as on a variety of spatial scales, from the local to the globe.
1. Volcanoes and minor earthquakes
2. Volcanoes, earthquakes and fold mountains.
3. Earthquakes and fold mountains.
4. Magma from volcanoes is filled with nutrients that makes land fertile.
Therefore, a geological event is a brief, spatially diverse, dynamic and ongoing occurrence in the history of the Earth.
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how many moles of nitroge are there in 50.0 g of nitrogen?
1.785714286 moles
The number of moles (n) for nitrogen is: [ n=50.0÷28.0 ] = 1.785714286 moles.
What are the two processes of ocean to cloud?
Answer: The excess amount changes from a gas into a liquid or solid (ice). The process of water changing from a gas to a liquid is called "condensation," and when gas changes directly into a solid, it is called "deposition." These two processes are how clouds form.
Calculate the percent composition by mass of each element in Al(OH)3.Al(OH)3. Use at least three significant figures.
Answer:
Explanation:
Al(OH)₃
Total molecular weight = 27 + 3 x ( 16+1)
= 78
Al = 27
% of Al = 27 x 100 / 78 = 34.61%
O = 48
% of O = 48 x 100 / 78 = 61.55 %
H = 3
% of H = 3 x 100 / 78
= 3.84%
Al = 34.61%.
O = 61.55%.
H = 3.84%.
Which statement accurate describes plate tectonics?
Answer:
the lithosphere is broken into sections called plates.
Answer:
The lithosphere is broken into sections called plates.
Explanation:
edge2020
How many grams of CO2 are produced from 10 grams of C2H6
Answer:
Explanation:
no of moles of C2H6=10/30=0.33
complete combustion of 2 moles of ethane produce 4 moles of CO2 therefore 0.33 moles of C2H6 produced 0.66 moles of CO2
now moles =given mass/molar mass
mass= moles*molar mass
mass of CO2=0.67*44=29.48 g
How do you determine whether an acid should be broken up into ions in the
complete ionic equation?
Answer:
When chemicals in solution react, the proper way of writing the chemical formulas of the dissolved ionic compounds is in terms of the dissociated ions, not the complete ionic formula. A complete ionic equation is a chemical equation in which the dissolved ionic compounds are written as separated ions.
5. How many moles of aluminum sulfate would contain 3.54 x 1025 sulfur atoms?
Answer:
19.6 moles of aluminum sulfate
Explanation:
Given parameters:
Number of sulfur atoms = 3.54 x 10²⁵ atoms
Unknown:
Number of moles of aluminum sulfate = ?
Solution:
Aluminum sulfate is expressed as;
Al₂(SO₄)₃
1 mole of Aluminum sulfate contains 3 moles of sulfur.
6.02 x 10²³ atoms are found in 1 mole of any substance;
3.54 x 10²⁵ sulfur atoms will be found in [tex]\frac{3.54 x 10^{25} }{6.02 x 10^{23} }[/tex] = 58.8moles of sulfur
1 mole of Aluminum sulfate contains 3 moles of sulfur.
or ;
3 moles of sulfur is contained in 1 mole of aluminum sulfate
58.8moles of sulfur will contain [tex]\frac{58.8}{3}[/tex] moles of aluminum sulfate
= 19.6 moles of aluminum sulfate
Is steel wool and vinegar an exothermic reaction? Explain.
Answer:
Vinegar contains acetic acid which removes this coating. When the protective coating is removed, oxygen in the atmosphere can reach the iron in the steel wool and a chemical reaction called oxidation occurs. ... This reaction is also an exothermic reaction. It creates heat energy
Explanation:
hope this helps u
Vinegar incorporates acetic acid which gets rid of this coating. When the defensive coating is removed, oxygen in the environment can reach the iron in the metal wool and a chemical reaction called oxidation occurs. This reaction is additionally an exothermic reaction. It creates warmth energy.
Hope it helped! Have a nice day! <3
Sulfur has an electronegativity of 2.58, while Cesium has a value of 0.79. Based on this information, they would have what kind of chemical bond?
Answer:
Ionic
Explanation:
Because sulphur is a non-metal and cesium is part of the group 1 Alkali Metals, this creates an ionic bond
Ionic bonds are created from one metal and one non-metal element.
This still is declared as Ionic despite the balance of this is Cs2S
Write the overall molecular equation for the reaction of hydroiodic acid ( HI ) and potassium hydroxide. Include physical states. Enter the formula for water as H2O .
Answer:
HI(aq) + KOH(aq) --> KI(aq) + H2O(l)
Explanation:
HI is an acid and KOH is a base, this means that the reaction would be a neutralization reaction.
The equation is given as;
HI + KOH --> KI + H2O
Adding the physical states we have;
HI(aq) + KOH(aq) --> KI(aq) + H2O(l)
As you move from N to Bi, the metallic properties of the element
A. increases.
C. remains the same.
B. decreases.
D. does not follow a trend.
Answer:
b. decreases
Explanation:
i just took a test on it
As you move from N to Bi, the metallic properties of the element decrease. The correct option is B.
What are nitrogen and bismuth?Nitrogen is a chemical element, whose chemical element is N. Nitrogen is a gas and its atomic number is 7. It is a non-metal and is present in group 15 of the periodic table.
Bismuth is a chemical element, whose chemical element is Bi. It is a post-transition metal, and it is also present in group 15 of the periodic table near arsenic and antimony. Its atomic number is 83.
Now, nitrogen and bismuth are present in the same line and group. Nitrogen is the first element of the group and going down, there is bismuth present in the group last. So the metallic property decreases from going down the group.
Thus, the correct option is B. decreases.
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A gas expands from 285 mL to 789 mL at constant temperature. How much work is done by the gas (joules) if it expands against a constant pressure of 6.00 atm?
Answer:
-306j
Explanation:
For this question we define an equation:
W = -Pext(Vj-Vi)-----> eqn 1
P = 6atm
Vi = 285 ml
We convert it to litre
= 285/1000 mL
= 0.285 L
Vj = 789 mL
When converted to litre
= 789/1000 mL
= 0.789 L
These values are all going to be put values in the eqn 2 above
W = -Pext(Vj-Vi)
W = -6.0x (0.789L - 0.285L)
W = -3.024
W = -3.024 x 101.33 J
This gives us the answer
W = -306 J
Thank you!
Answer: -306 J
3.0 x 108 m/s is the
Answer:
Speed of light
Explanation:
The value 3.0 x 10⁸m/s is taken as the speed of light.
It is a constant.
It implies that light travels a distance of 3 x 10⁸ in just one second. This value is for the speed of light in a vacuum when there are not particles obstructing its movement. The speed of electromagnetic radiations in free space is also taken as the speed of light.How did the instrument in the picture help to disprove part of Dalton's atomic model?
A)
It showed all matter is made of atoms and that atoms are indivisible and
indestructible.
B)
It showed that all atoms of a particular element are not identical.
C)
It showed that compounds are formed by a combination of two or more
different kinds of atoms.
D)
It showed that a chemical reaction is a rearrangement of atoms.
No
Answer:
It’s b;)
Explanation:
Answer:
B is correct
Explanation:
A very new item just arrived in the market. It is very good for construction, and other things. Now, this item has chemicals, and in every drop, there are 400 grams of NaCI. If there are 10 drops in this item, how many grams of NaCI are in one bottle?
Answer: 4,000 grams of NaCI
Explanation:
We know that there are 400g of NaCI in one drop.
This bottle has 10 drops of this item.
So, we have to multiply the amount of NaCI in a drop by the amount of drops.
400 x 10 = 4,000.
The answer to the question is 4,000. Hope this helps!
what are the reactants in a cheese sandwich
Answer:
cheese and bread
Explanation:
2 bread 1 cheese = cheese sandwich
When forming ions, nitrogen will gain or lose how many electrons, forming a cations or anions with a what charge?
Answer:
Nonmetals form negative ions (anions). A nitrogen atom must gain three electrons to have the same number of electrons as an atom of the following noble gas, neon. Thus, a nitrogen atom will form an anion with three more electrons than protons and a charge of 3−.
Explanation:
have advanced