Answer:
The correct answer is 146 g/mol
Explanation:
Freezing point depression is a colligative property related to the number of particles of solute dissolved in a solvent. It is given by:
ΔTf = Kf x m
Where ΔTf is the freezing point depression (in ºC), Kf is a constant for the solvent and m is the molality of solution. From the problem, we know the following data:
ΔTf = 1.02ºC
Kf = 5.12ºC/m
From this, we can calculate the molality:
m = ΔTf/Kf = 1.02ºC/(5.12ºC/m)= 0.199 m
The molality of a solution is defined as the moles of solute per kg of solvent. Thus, we can multiply the molality by the mass of solvent in kg (250 g= 0.25 kg) to obtain the moles of solute:
0.199 mol/kg benzene x 0.25 kg = 0.0498 moles solute
There are 0.0498 moles of solute dissolved in the solution. To calculate the molar mass of the solute, we divide the mass (7.27 g) into the moles:
molar mass = mass/mol = 7.27 g/(0.0498 mol) = 145.9 g/mol ≅ 146 g/mol
Therefore, the molar mass of the compound is 146 g/mol
8. Why is the magnetic force considered to be a noncontact force?
Answer:
Magnetic forces are non contact forces; they pull or push on objects without touching them. Magnets are only attracted to a few 'magnetic' metals and not all matter. Magnets are attracted to and repel other magnets.
Hope this helps!!!
Explanation:
give reason deliquescent substance truns into liquid when exposed to atmosphere air
Calculate the number of moles in 2.60 grams of SnO2 ? Please show your work to receive credit.
Answer:
There are 0.017252 moles in SnO2
Explanation:
n= m/M
n=2.6/(118.710 + 2(16))
n= 2.6/150.71
n= 0.017252
Remeber to round based on the significant digits in the question.
How might ocean waves affect a beach over thousands of years? Explain your answer.
Answer:
Explanation:
Well a oceans waves could erode the beach it it is a rocky one, it can wash the sand out and can cause rocks to fall.
During photosynthesis, plants and some other organisms use energy from the sun to convert (change): carbon dioxide (CO2) and water (H2O) into ____________ (O2) and __________ (C6H12O6)
Answer:
CO2 + H2O → O2 + C6H12O6
CO2 = carbon dioxide
H2O = water
O2 = oxygen
C6H12O6 = glukose
If you worked at a job for $9.00/hour, what type of correlation is the number of hours worked and your take-home pay?
Answer:
There are no options to this question, however, it can be answered. The answer is:
POSITIVE CORRELATION
Explanation:
Correlation refers to the relationship between two variables. It shows how related two variables are to one another. Hence, when two variables are correlated, there exists a relationship between them. Correlation can either be positive or negative depending on how related they are.
A positive correlation is that correlation in which the two variables are influenced to go in the same direction. That is, when one variable increases, the other variable increases as well and vice versa. This is the case in this question regarding the correlation between number of hours worked and take-home pay.
As the number of hours worked increases, the take-home pay also increases and vice versa. Hence, it is a type of POSITIVE CORRELATION
Which statement BEST explains why the Moon is visible from the Earth?
1) The Moon reflects light from the Sun.
2) The Moon is always lit up by the Sun for us to see.
3) The Moon reflects light from the Earth.
4) The Moon produces its own light through radiation.
Answer: The answer is the ''The moon is always lit up by the sun for us to see.''
Explanation: The moon is directly illuminated by the sun.
Ok
A plant part that contains a tiny new plant, or embryo
seed
spore
root
flower
When does carbon dioxide absorb the most heat energy?
during freezing
during deposition
during sublimation
during condensation
Answer:
during sublimation
Explanation:
just took the test
What was one main point of Dalton’s atomic theory?
A. That atoms were made up of positive and negative charges
B. That atoms changed as they formed compounds
C. That atoms has a nucleus at the center
D. That atoms made up the smallest form of matter
The main point of Dalton’s atomic theory is that the atoms are made up the smallest form of matter. Hence Option (D) is Correct
What is Dalton's Atomic Theory ?
The 5 main points of Dalton's Atomic theory was ;
Elements are composed of extremely small particles called atoms that are indivisible and indestructibleAll atoms of a given element are identical; they have the same size, mass, and chemical propertiesAtoms of 1 element are different from the atoms of all other elementsCompounds are composed of atoms of more than 1 element. The relative number of atoms of each element in a given compound is always the same.Chemical reactions only involve the rearrangement of atoms. Atoms are not created or destroyed during chemical reactions.Therefore, The main point of Dalton’s atomic theory is that the atoms are made up the smallest form of matter. Hence Option (D) is Correct
Learn more about Atom here ;
https://brainly.com/question/657632
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Answer:
D is correct
Explanation:
Identify the oxidizing and reducing agent in the following reaction, and determine which element is oxidized and which is reduced. Fe2+(aq) + ClO2(aq) → Fe3+(aq) + ClO2–(aq) ClO2 is the reducing agent and Fe2+ is the oxidizing agent . Fe is oxidized and Cl is reduced. g
Answer:
Explanation:
Fe⁺²(aq) + ClO₂(aq) → Fe⁺³(aq) + ClO₂⁻(aq)
Here oxidation number of Fe is increased from +2 to +3 , so Fe is oxidised .
The oxidation number of Cl is reduced from + 4 to +3 so Cl is reduced .
So ClO₂(aq) is oxidising agent and Fe⁺²(aq) is reducing agent .
.
Ag+1, NO3-1
+
Na+1, I-1
->
Answer:
0.3+Na
Explanation:
Which atom has exactly 15 protons?
Answer:
Phosphorus
Explanation:
How is matter divided?
An ion formed from an atom has a 1- charge. The number of electrons present in the ion is 36 and the number of neutrons is 46. Identify the element by typing the name. For example: Hydrogen or Sodium.
Answer:
Bromine can become an ion when it gains an electron. Br- is a negative ion. Its known as an anion. Bromine has 35 protons=35 electrons. one added electron gives it 36 electrons and it becomes an anion.
Explanation:
Bromine can have isotopes having 44 and 46 neutrons.
how many moles are in a 4.2 gram gold sample
a 108ml sampl of gas has a mass of 77.96mg at a pressure of 1140mmhg and temperature of 183°c .what is the molar mass of the gas ?
Answer:
146.85 g/mol
Explanation:
PV=nRT
n=mass/molar mass
covert from mmhg to atm = 0.184 atm
convert from ml to L= 0.108 L
convert from degree C to K= 456.15 K
convert from mg to g= 0.07796g
then rearrange the formula:
n=PV/RT
=(0.184)(0.108)/(0.08206)(456.15)
n= 5.308*10^(-4)
rearrange the n formula interms of molar mass:
Molar mass= mass/n
=0.07796/(5.308*10^-4)
molar mass= 146.85g/mol
Answer:
Molar mass = 20 g/mol
Explanation:
Given data:
Volume of gas = 108 mL
Mass of gas = 77.96 mg (77.96/1000 = 0.08 g)
Pressure of gas = 1140 mmHg
Temperature of gas = 183°C
Molar mass of gas = ?
Solution:
First of all we will calculate the number of moles of gas.
PV = nRT
R = general gas constant = 0.0821 atm.L/ mol.K
Now we will convert the units and then we will put the values in formula.
Volume of gas = 108 mL× 1 L/1000 mL= 0.108 L
Pressure of gas = 1140 mmHg× 1 atm / 760 mmHg = 1.5 atm
Temperature of gas = 183+273 = 456 K
PV = nRT
1.5 atm ×0.108 L = n × 0.0821 atm.L/ mol.K ×456 K
0.162 atm.L = n ×37.44 atm.L/ mol
n = 0.162 atm.L/37.44 atm.L/ mol
n = 0.004 mol
Molar mass of gas:
Number of moles = mass/molar mass
0.004 mol = 0.08 g / molar mass
Molar mass = 0.08 g /0.004 mol
Molar mass = 20 g/mol
Which is denser a liquid or solid why?
Answer:
Liquids are usually less dense than solids but more dense than air. Temperature can change a liquid's density. For example, increasing the temperature of water causes the molecules to spread farther apart. The farther apart the molecules are, the less dense the water is.
Answer:
Solids are usually much more dense than liquids and gases, but not always.
Explanation:
Mercury, a metallic element that is a liquid at room temperature, is denser than many solids. Aerogel, a very unusual human-made solid, is about 500 times less dense than wate
What kind of metal is Cu?
Transition metal
Alkaline earth metal
Alkali metal
Answer: Transition metal
Explanation: Copper is definitely a transition metal because the Cu2+ ion has an incomplete d level.
Time is always the same on the same line of latitude or longitude
Answer:
Longtitude
No explanation :)
You are given 3 liquid samples – A, B, C and told that one is water, one is ethanol, and one is ether (d=0.700 g/mL). Each sample is 10.0 mL. the masses are as follows: A = 10.0 g, B= 7.00 g, C = 8.00 g. Identify each of the substances using density problems.
Answer:
im just trying to get work done i will help u if i knew it
19. A beam of light can be seen as it passes through a(n).
a. Element
I
b. Compound
C. Solution
d. Heterogeneous Mixture
A beam of light can be seen as it passes through a
What is the particle behavior of an liquid?
Answer: The particles are moving fast but close together.
Answer:
its in the explanation.
Explanation:
1.In liquids, particles are quite close together and move with random motion throughout the container. Particles move rapidly in all directions but collide with each other more frequently than in gases due to shorter distances between particles.
2.It assumes the shape of the part of the container which it occupies particles can move/slide past one another.
Hope this helps. :)
Vocabulary Terms: Please copy down the definitions for words below from the Smart Screen.
Length is defined as
Height is defined as
Circumference is defined as
Perimeter is defined as
Diagonal is defined as
Diameter is defined as
Answer:
Explanation:
Length: Length is a measure of distance
Height:The measurement from base to top or (of a standing person) from head to foot.
Circumference:The enclosing boundary of a curved geometric figure, especially a circle
Perimeter: Length of the outline of a shape.
Diagonal:A line segment that goes from one corner to another, but is not an edge. So when we directly join any two corners (called "vertices") which are not already joined by an edge, we get a diagonal. Diagonals of Polygons.
Diameter: A straight line passing from side to side of any figure or body, through its center.
How is stress and strain related to elastic deformation?
Answer:
elastic materials like rubber have small k
Explanation:
is the change in length divided by the original length of the object.
What is the frequency of a wave having 4.90 x 10 -12 J of energy?
Answer:
The answer is
[tex] \huge 7.40 \times {10}^{21} Hz[/tex]
Explanation:
To find the frequency of the wave we use the formula
[tex]f = \frac{E}{h} \\ [/tex]
where
E is the energy
f is the frequency
h is the Planck's constant which is
6.626 × 10-³⁴ Js
From the question
E = 4.90 × 10-¹² J
So we have
[tex]f = \frac{4.90 \times {10}^{ - 12} }{6.626 \times {10}^{ - 34} } \\ [/tex]
We have the final answer as
[tex]7.40 \times {10}^{21} \: \: Hz[/tex]
Hope this helps you
Violet light has a wavelength of 4.50 x 10-12 m. What is the frequency?*
3 points
1.5 x10^20 1/s
0.0135 1/s
6.77x10^19 1/5
3x10^8 1/s
Green light has a frequency of 6.73 x 1014 1/s. What is the wavelength?*
3 points
2.24x10^6 m
4.46x10^-7 m
2.02 x 10^23 m.
4.95 x 10^-24 m
3 points
What is the energy (Joules) of violet light with a frequency = 3.43 x 10^14
1/s? *
4.54x10^-19 J
1.99x10^-25 J
1.93 x 10^-48 J
2.27 x 10^-19 J
Answer:
Frequency = 6.67x10¹⁹ s⁻¹
Wavelength = 4.46x10⁻⁷m
e = 2.27x10⁻¹⁹J
Explanation:
To convert frequency to wavelength and vice versa we use the equation:
Wavelength = Speed of light / Frequency
Speed ligth is 3x10⁸m/s
For a wavelength of 4.50x10⁻¹²m:
4.50x10⁻¹²m = 3x10⁸m/s / Frequency
Frequency = 3x10⁸m/s / 4.5x10⁻¹²m
Frequency = 6.67x10¹⁹ s⁻¹For a frequency of 6.73x10¹⁴s⁻¹:
Wavelength = 3x10⁸m/s / 6.73x10¹⁴s⁻¹
Wavelength = 4.46x10⁻⁷mAnd energy, e, from frequency, is obtained as follows:
e = h ₓ frequency
Where h is Planck's constant, 6.626x10⁻³⁴J*s
e = 6.626x10⁻³⁴J*s*3.43x10¹⁴s⁻¹
e = 2.27x10⁻¹⁹JPhosphoric acid, which is commonly used as rust inhibitor, food additive and etching agent for dental and orthopedic use, can be synthesized using a two-step thermal process. In the first step, phosphorus and oxygen react to form diphosphorus pentoxide:
P4(l)+ 5O2(g) → P2O5()
In the second step, diphosphorus pentoxide and water react to form phosphoric acid:
P2O5(g)+ 3H2O → 2H3PO4
Write the net chemical equation for the production of phosphoric acid from phosphorus, oxygen and water. Be sure your equation is balanced.
Answer:
P4(l) + 5O2(g) + 6H2O(l) → 4H3PO4(aq)
Explanation:
Step 1
P4(l)+ 5O2(g) → 2P2O5()
Step 2
2P2O5(g)+ 6H2O(l) → 4H3PO4(aq)
Overall balanced equation;
P4(l) + 5O2(g) + 6H2O(l) → 4H3PO4(aq)
Notice carefully that the correct coefficients were used to balance the equations and obtain the accurate overall reaction equation. All the steps involved were shown above. Reactants that occur on both sides cancel out and do not appear in the final equation.
Thermal Energy moves from a colder region to a warmer region. *
True
False
False.
There is more thermal energy (faster moving particles) in a warmer region, so they spread out over time, warming up the other regions and losing energy.
Please mark as Brainliest.
I need help with this
Answer:
2 nitrogen molecules are present
1 oxygen molecule is present
1 n2o molecules are present