Can someone please help me quick !!!
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:
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
Ammonia, NH3 is a common base with Kb of 1.8 X 10-5. For a solution of 0.150 M NH3:
Write the equation for the ionization of ammonia in water.
List all species present in the solution AND determine the concentrations of each.
Determine the pH of this solution.
The concentrations : 0.15 M
pH=11.21
Further explanationThe ionization of ammonia in water :
NH₃+H₂O⇒NH₄OH
NH₃+H₂O⇒NH₄⁺ + OH⁻
The concentrations of all species present in the solution = 0.15 M
Kb=1.8 x 10⁻⁵
M=0.15
[tex]\tt [OH^-]=\sqrt{Kb.M}\\\\(OH^-]=\sqrt{1.8\times 10^{-5}\times 0.15}\\\\(OH^-]=\sqrt{2.7\times 10^{-6}}=1.64\times 10^{-3}[/tex]
[tex]\tt pOH=-log[OH^-]\\\\pOH=3-log~1.64=2.79\\\\pH=14-2.79=11.21[/tex]
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:
PLS HURRY
What methods are you using to test this (or each) hypothesis?
Answer:
Fair test.
PLS GIVE BRAINLIEST
Consider the balanced equation.
CuSO4 + Zn Right arrow. ZnSO4 + Cu
If 200.0 g of copper(II) sulfate react with an excess of zinc metal, what is the theoretical yield of copper?
1.253 g
50.72 g
79.63 g
194.3 g
Answer:
79.63
Explanation:
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
PLS HELP!!!
What does it mean when there is a physical change?
A new substance has been formed.
Matter has changed on the molecular level.
Matter has changed from one substance into another.
Matter has changed size, shape or form.
Answer:
Physical Change. Physical changes are changes in which no bonds are broken or formed. This means that the same types of compounds or elements that were there at the beginning of the change are there at the end of the change.
how many elements are present No and NO
compare the size of I, I+ and I-
umm explanation pls so i answee
Which of the following elements can only form single covalent bonds when forming molecular compounds?
a) Nitrogen
b) Hydrogen
c) Carbon
d) Oxygen
Hydrogen can only form single covalent bonds when forming molecular compounds. Therefore, option B is correct.
What is covalent bond?A covalent bond is a type of chemical bond formed between two or more atoms in which electrons are shared between them. Covalent bonds usually occur between nonmetal atoms and are formed by the sharing of valence electrons.
Hydrogen can only form a single covalent bond because it has only one valence electron and needs one more electron to complete its valence shell, making it stable.
Nitrogen can form triple covalent bonds, carbon can form multiple covalent bonds, and oxygen can form double covalent bonds in molecular compounds.
Thus, option B is correct.
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what is the source of the force that moves the tectonic plates along this plate boundary
Answer:
Mantle convection
Explanation:
The source of the force that moves tectonic plates along plate boundaries is as a result of the mantle convection.
Heat energy produced in the mantle especially from radioactive decay is a very important source of internal heat that drives plate motion. Denser and cold materials close to the over-riding lithosphere above sinks deep into the mantle. Hotter and lighter materials rises to the surface. This sets up a convection cell by which the plates above are driven.In a classroom, which comparison would a teacher most likely use for describing a mole?
a cup of water and a liter of oil
a dozen eggs and a dozen jellybeans
a jar of jellybeans and a gram of salt crystals
20 marbles in a bag and 10 large ice cubes
Answer:
B
Explanation:
a mole is "a chemist's dozen" lol
Automobile air bags use the decomposition of sodium azide as their sources of gas for rapid inflation, represented in the reaction below. What mass (in grams) of NaN4is required to provide 40.0 L of N2 at 25°C and 763 torr?
Answer:
The answer is 95 degree celcius
What happens to the gravitational potential energy of an object if you bring it higher with respect to the ground? *
Answer:
Increases
Explanation:
The gravitational potential energy of an object increases as you bring it higher with respect to the ground.
Gravitational potential energy depends on the mass, height and gravity between two bodies;
Gravitational potential energy = mgh
m is the mass
g is the height
h is the height
We can clearly see that the higher the elevation, the more the value of the gravitational potential energy.A. The chemical formula for iron (III) sulfate is Fe2(SO4)3. How many atoms of each element are present?
2 iron, 3 sulfur, 12 oxygen
3 iron, 3 sulfur, 12 oxygen
2 iron, 1 sulfur, 4 oxygen
6 iron, 3 sulfur, 12 oxygen
B.How many moles of hydrogen are in 1.8 mole(s) of quinine?
Express your answer using two significant figures.
C. How many moles of carbon are in 5.4 moles of quinine?
Express your answer using two significant figures.
D. How many moles of nitrogen are in 2.0×10−2 mole of quinine?
Express your answer using two significant figures.
Answer:
A. 2 Fe, 3 S and 12 O
B. 43 moles of H
C. 1.0×10² moles of C
Explanation:
A. Formula for iron (III) sulfate is Fe₂(SO₄)₃
This salt has 2 atoms of iron and 3 sulfates, so in total we have:
2 Fe, 3 S and 12 O
Pay attention to the subscripts
B. Formula for quinine is: C₂₀H₂₄N₂O₂
If we continue with the example before we can say that 1 mol of Iron (III) sulfate contains 2 moles of Fe, 3 moles of S and 12 moles of O
Then, 1 mol of quinine contains 24 moles of H
So 1.8 moles of quinine, may contain (1.8 . 24) /1 = 43 moles of H
C. 1 mol of quinine contains 20 moles of C
5.4 moles of quinine may contain (5.4 . 20) /1 = 1.0×10²
(As the answer must be in 2 significant figures and the real answer is 108, I had to use scientific notation)
How many milliliters of 2.00 M H2SO4 will react with 28.0 g of NaOH?
Taking into account the reaction stoichiometry and the definition of molarity, 175 mL of 2 M H₂SO₄ will react with 28.0 g of NaOH.
Reaction stoichiometryIn first place, the balanced reaction is:
H₂SO₄ + 2 NaOH → Na₂SO₄ + 2 H₂O
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
H₂SO₄: 1 moleNaOH: 2 moles Na₂SO₄: 1 moleH₂O: 2 molesThe molar mass of the compounds is:
H₂SO₄: 98 g/moleNaOH: 40 g/moleNa₂SO₄: 142 g/moleH₂O: 18 g/moleThen, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:
H₂SO₄: 1 mole× 98 g/mole= 98 gramsNaOH: 2 moles× 40 g/mole= 80 gramsNa₂SO₄: 1 mole× 142 g/mole= 142 gramsH₂O: 2 moles× 18 g/mole= 36 gramsDefinition of molarityMolar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:
[tex]Molarity= \frac{number of moles}{volume}[/tex]
Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].
Moles of H₂SO₄ requiredThe following rule of three can be applied: If by reaction stoichiometry 80 grams of NaOH react with 1 mole of H₂SO₄, 28 grams of NaOH react with how many moles of H₂SO₄?
[tex]moles of H_{2}S O_{4} =\frac{28 grams of NaOHx1 mole ofH_{2}S O_{4} }{80 grams of NaOH}[/tex]
moles of H₂SO₄= 0.35 moles
Volume of H₂SO₄ requiredIn this case, you know:
Molarity= 2 M= 2 [tex]\frac{moles}{liter}[/tex]amount of moles= 0.35 molesReplacing in the definition of molarity:
[tex]2 \frac{moles}{liter}= \frac{0.35 moles}{volume}[/tex]
Solving:
2 [tex]\frac{moles}{liter}[/tex] × volume= 0.35 moles
volume= 0.35 moles ÷ 2 [tex]\frac{moles}{liter}[/tex]
volume= 0.175 liters= 175 mL (being 1 L= 1000 mL)
Finally, 175 mL of 2 M H₂SO₄ will react with 28.0 g of NaOH.
Learn more about
the reaction stoichiometry:
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molarity:
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Graphite is sometimes used to reduce the friction between
two surfaces that are rubbing together.
Explain how it does this.
Graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. Therefore, this happen because of weak covalent bond.
What is graphite?Graphite is among the most prevalent carbon allotropes. It is also the stable allotrope for carbon, and as such, it is employed in electrochemistry to define the heat of synthesis of carbon compounds. With a hardness of 2.09-2.23 g/cm3, graphite is an excellent conductor of electricity and heat.
Graphite is a large covalent structure in which each carbon atom is covalently linked to three other carbon atoms. Graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. This happen because of weak covalent bond.
Therefore, graphite is sometimes used to reduce the friction between two surfaces that are rubbing together. This happen because of weak covalent bond.
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what are the reactants in a cheese sandwich
Answer:
cheese and bread
Explanation:
2 bread 1 cheese = cheese sandwich
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
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)
Why is Mg++ smaller than Mg atom?
Answer:
The magnesium ion is much smaller than the magnesium atom because magnesium atom contains more electrons as compared to magnesium ion. Explanation: ... Whereas when an atom tends to lose an electron then it acquires a positive charge and size of the atom tends to increase.
Answer:
Because it looses it two electrons to form a stable octet Ionic form..........
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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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
Based on your lab report, provide the chemical reaction that occurs in Benedict's test for the following molecule.
Explanation:
I DONT UNDERSTAND WHAT U WANT TO SAY
True 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.
9. What are the advantages of using an indicator to inform pH measurements? What are the advantages of using a pH meter?
Answer:
The advantages of using an indicator to inform pH measurements:
It gives a mathematically result of the pH, in addition, it gives the precise pH of solvent, and it also gives an idea of the straight of the solution also.
Now, the advantage of using a pH meter:
It is a rapid method to characterize between acids, bases. However, this method does not show how strong acid or base actually are, plus it tends to gives a range of acidity or basicity not quite accurate as a result.
Which determines the reactivity of an alkali metal?
a. it's boiling and melting points
b. the shininess of its surface
c. the number of protons it has
d. it's ability to lose electrons
Answer:
d. It's ability to lose electrons