1. 55 grams of salt are added to 100 L of water to make a saline solution.
What is the g/L concentration of the aqueous solution?
Show your work!
Answer:
0.55g/L
Explanation:
Given parameters;
Mass of salt = 55g
Volume of water = 100L
Unknown:
g/L concentration = ?
Solution:
To solve this problem, we must understand that concentration is the amount of solute per solution
g/L concentration = [tex]\frac{55}{100}[/tex] = 0.55g/L
Suppose that 3.33 g of acetone at 25.0 °C condenses on the surface of a 44.0-g block of aluminum that is initially at 25 °C. If the heat released during condensation goes only toward heating the metal, what is the final temperature (in °C) of the metal block?
Answer:
68.6 °C
Explanation:
From conservation of energy, the heat lost by acetone, Q = heat gained by aluminum, Q'
Q = Q'
Q = mL where Q = latent heat of vaporization of acetone, m = mass of acetone = 3.33 g and L = specific latent heat of vaporization of acetone = 518 J/g
Q' = m'c(θ₂ - θ₁) where m' = mass of aluminum = 44.0 g, c = specific heat capacity of aluminum = 0.9 J/g°C, θ₁ = initial temperature of aluminum = 25°C and θ₂ = final temperature of aluminum = unknown
So, mL = m'c(θ₂ - θ₁)
θ₂ - θ₁ = mL/m'c
θ₂ = mL/m'c + θ₁
substituting the values of the variables into the equation, we have
θ₂ = 3.33 g × 518 J/g/(44.0 g × 0.9 J/g°C) + 25 °C
θ₂ = 1724.94 J/(39.6 J/°C) + 25 °C
θ₂ = 43.56 °C + 25 °C
θ₂ = 68.56 °C
θ₂ ≅ 68.6 °C
So, the final temperature (in °C) of the metal block is 68.6 °C.
The final temperature of the metal block is 74.97°C
What is the specific heat?The specific heat of a substance is the required quantity of heat needed to raise the temperature of 1 gram of the substance by 1° C.
From the parameters given:
The mass of acetone = 3.33 gThe number of moles of acetone is:
[tex]\mathbf{= 3.33 g \times \dfrac{mol}{58.08 \ mol}}[/tex]
= 0.0573 mol
At standard conditions, the heat of vaporization of acetone is:
[tex]\mathbf{\Delta H = 32.0 \ kJ/mol \times 0.0578 \ mol } \\ \\ \mathbf{\Delta H = 1.8496 \ kJ } \\ \\ \mathbf{ \Delta H = 1.85 \times 10^3 \ J}[/tex]
Given that:
The mass of the metal (m) = 44.0 gThe initial temperature [tex]\mathbf{T_1}[/tex] = 25° CThe final temperature [tex]\mathbf{T_2 = ???}[/tex]The specific heat of the aluminum is = 0.903 J/g° C
The heat energy can be computed as:
q = msΔT
q = 41 g × 0.903 J/g° C × (x - 25°C)
Using the calorimetry principle, heat energy lost by metal = heat energy gained by acetone.
i.e.
[tex]\mathbf{q_{(acetone)} gain = q_{(metal)} lost }[/tex]
[tex]\mathbf{-1.85 \times 10^3 \ J = - 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]
[tex]\mathbf{1.85 \times 10^3 \ J = 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]
[tex]\mathbf{(x - 25 ^0 C) = \dfrac{1.85 \times 10^3 \ J }{ 41 g \times 0.903 \ J/g^0 C}}[/tex]
[tex]\mathbf{(x - 25 ^0 C) = 49.97^0 C}}[/tex]
[tex]\mathbf{x = 49.97^0 C+25 ^0 C}}[/tex]
x = 74.97 °C
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A certain atom has 50 protons and 69 neutrons. Which statement(s) below are true about this atom? Choose ALL that apply.
this atom is an atom of thulium (Tm)
m this atom has a mass of 69 amu
this atom is an isotope of tin-120
m this atom has an atomic number of 50
Answer:
D.) This atom has an atomic number of 50
Explanation:
A is wrong because we determine the type of atom by their number of protons, not the number of neutrons. This makes the atom Tin (Sn).
B is wrong because both protons and neutrons contribute to the weight of an atom, not just neutrons
C is wrong because the correct name for this isotope would be tin-119, which is calculated by adding the protons and neutrons
D is correct because isotopes of the same element always share the same atomic number
How many grams are in 3.00 x 10^24 molecules of Zn(C2H3O2)2?
Answer:
Mass = 917.4 g
Explanation:
Given data:
Number of molecules = 3.00 ×10²⁴ molecules
Mass in gram = ?
Solution:
1 mole contain 6.022 × 10²³ molecules
3.00 ×10²⁴ molecules × 1 mol / 6.022 × 10²³ molecules
0.5×10¹ mol
5 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 5 mol × 183.48 g/mol
Mass = 917.4 g
What causes the wind and weather on earth plz help
Chloe wants to lighten the color of her dark hair, which will require the use of both haircolor and hydrogen peroxide. Hydrogen peroxide (H2O2) is an example of a(n):
compound molecule.
elemental molecule.
immiscible liquid.
miscible liquid.
Answer:
H₂O₂
Explanation:
Hydrogen peroxide is a typical example of a compound molecule. A compound is made up of one or more atoms that are combined together in a definite grouping.
The properties of a compound is different from those of the elements that combines to from them.
A molecule is a covalent compound that has discrete or separate units. The formula of such compound represents a certain discrete entity. From this problem, we know that hydrogen peroxide is a covalent compound24. What type of cloud is in the picture?
cumulus
cirrus
altostratus
stratus
Explanation:
alto cumulus is the pic
What is the function of the vacuole?
to make proteins
for storage
to transport materials
to control all cell functions
Explanation:
In animal cells, vacuoles are small and help sequester waste products. In plant cells, vacuoles help maintain water balance. Therefore the answer should be B. For Storage
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i really need help with this question can you guys help me
A cube has a mass of 42 grams and a volume of 15 cubic centimeters. What is it’s density?
(Show your work or complete all problems for brainliest)
Answer:
2.8g/cm³
Explanation:
Given parameters:
Mass of cube = 42g
Volume of cube = 15cm³
Unknown:
Density of the cube = ?
Solution:
Density is defined as the mass per unit volume of a substance. It is mathematically expressed as:
Density = [tex]\frac{mass}{volume}[/tex]
So;
Density = [tex]\frac{42}{15}[/tex] = 2.8g/cm³
What is the product(s) in the reaction below?
Answer:
imma go with the answer B
The product in the reaction [tex]\rm Zn + 2HCl \rightarrow[/tex] is [tex]\rm ZnCl_2 + H_2[/tex]. The correct answer is option D.
A reaction is a process that involves the transformation of one or more substances into one or more different substances.
The reaction between zinc (Zn) and hydrochloric acid (HCl) is a classic example of a single displacement reaction. In this reaction, zinc reacts with hydrochloric acid to produce zinc chloride ([tex]\rm ZnCl_2[/tex]) and hydrogen gas ([tex]\rm H_2[/tex]).
The balanced chemical equation for this reaction is:
[tex]\rm Zn(s) + 2HCl(aq) \rightarrow ZnCl_2(aq) + H_2(g)[/tex]
Therefore, the product of the reaction between zinc and hydrochloric acid is zinc chloride ([tex]\rm ZnCl_2[/tex]) and hydrogen gas ([tex]\rm H_2[/tex]). Option D is the correct answer.
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mass = 325.2 volume = 62.5 cm what's the density ?
Answer:
159571 lb or cubic feet
Explanation:
PLS HELP THIS IS DUE TODAY!!
Answer:
I think it would be Yellow
what two types of evidence are used to classify organisms. Which animal shares the most traits with humans and do both lemurs and humans have the trait listed at Point D explain?
Explanation:
6.The main pieces of evidence that scientists use to classify organisms are essentially form and evolutionary relationships.
9. chimpanzee
10. The answer is no, lemurs are not bipedal, i.e, they don't use two legs for walking like human do and they don't have language like ours.
What is it that lives if it is fed, and dies if you give it a drink
Answer:
fire
Explanation:
Answer:
ants if you splash a ant with sum water that shít is dead
The magnifying power of a telescope is computed by dividing the focal length of its objective by _______.
Answer:
by focal length of the eyepiece.
Explanation:
hope it helps!!plz mark as brainleist.
How many moles are in 9.07 x 10^23 atoms of sodium chloride?
Answer:
1.5 moles of sodium chloride are present.
Explanation:
Given data:
Number of moles of sodium chloride = ?
Number of atoms of sodium chloride = 9.07×10²³
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
9.07×10²³ atoms × 1 mol / 6.022 × 10²³ atoms
1.5 moles of sodium chloride are present.
Could someone help me with this thank you!
Answer:
The answer is D
I searched it up to verify.
Answer: I think the possible answer is B or D
Explanation: There are few of the energies like: Gravitational, electrical, Chemical.....
A chemist is studying the properties of a gas under various conditions. He observes that when the gas is at room temperature and low pressure, it behaves as an ideal gas. When the gas is cooled to 10 kelvin and is placed under high pressure, however, it deviates significantly from an ideal gas. Explain these observations
Answer:
An ideal gas is a theoretical concept and a real gas behaves in an ideal manner under conditions which includes a high temperature and a low pressure such that the gas has high kinetic energy, and the intermolecular forces between the molecules are weak
The Ideal Gas Law is P·V = n·R·T
Where;
P = The pressure of the gas
V = The volume of the gas
n = The number of moles of the gas
R = The Universal Gas Constant
T = The temperature of the gas
For a gas cooled to 10 Kelvin and placed under high pressure, the interaction between individual gas molecules increases, and the kinetic energy of the gases is much lower and more comparable to the inter molecular forces between the gas molecules, which in turn produces observable changes from the initial ideal behavior of the gas such that the gas behavior deviates from the Ideal Gas Laws appreciably and are better modelled by the Van der Waals Equations which takes into account, the volume the gas particles occupy and the intermolecular forces between the molecules
The Van der Waals equation is presented as follows;
[tex]P = \dfrac{R \cdot T}{V - b} - \dfrac{a}{V^2}[/tex]
Where;
V = The molar volume
a = The gas constant a represents the attractive forces between the gas particles
b = Represent the volume occupied by the particles of the gas
Explanation:
Answer: A, B, & C
Explanation:
A. The ideal gas model assumes that gas particles experience no intermolecular attractions and these forces cause the gas to deviate from ideal behavior.
B. At very low temperatures, gas particles move slowly.
C. At very high pressures, gas particles are very close together.
Got it right on edge :)
A student performed an investigation to determine if the rate of photosynthesis in elodea is affected by a higher than normal concentration of carbon dioxide gas in the water in which the plant is growing. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant. In this investigation, what would be the best indicator of the rate of photosynthesis? a a change in the color of the plant b an increase in the length of the elodea plant over a period of 12 hours c the amount of light that is transmitted through the water d the amount of oxygen collected over a period of 12 hours
Answer:
D. the amount of oxygen collected over a period of 12 hours
Explanation:
Photosynthesis is a metabolic reaction performed by the cells of plant. In this reaction, light is used as an energy source to combine carbon dioxide (CO2) and water (H2O) to produce glucose and oxygen gas (O2) as products. In every chemical reaction including photosynthesis, an increase in concentration of reactants will increase the rate of the reaction, which is evident in the amount of products formed.
According to this question where a student is performing an investigation to determine the relationship between a higher than normal concentration of carbon dioxide gas and the rate of photosynthesis. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant.
Based on the above explanation, the best indicator of the rate of photosynthesis in this investigation will be THE AMOUNT OF OXYGEN COLLECTED OVER A PERIOD OF 12 HOURS.
How many moles are there in 2.4 x 10 24 atoms of He?
Group of answer choices
6.0 mol
2.4 x 10^24 mol
2.0 mol
4.0 mol
Answer:
4 mol
Explanation:
Given data:
Number of atoms of He = 2.4 × 10²⁴ atoms
Number of moles of He = ?
Solution:
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
2.4 × 10²⁴ atoms × 1mol / 6.022 × 10²³ atoms
0.398× 10¹ mol
3.98 mol ≅ 4 mol
what is the difference between polar and non-polar
Answer:
Polar molecules occur when there is an electronegativity difference between the bonded atoms. Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out.
Explanation:
Polar molecules occur when there is an electronegativity difference between the bonded atoms. Nonpolar molecules occur when electrons are shared equal between atoms of a diatomic molecule or when polar bonds in a larger molecule cancel each other out.
Please help me
There are many different renewable resources available in Florida. Which of the following can be described as a renewable resource?
Which reactions are the reverse of one another? condensation and addition addition and elimination elimination and condensation substitution and addition
Answer: addition and elimination
Explanation:
In addition you add and in elimination you remove (or subtract)
The reactions that are the reverse of one another are addition and elimination. Details about types of reactions are as follows.
What is a reaction?A reaction is the transformation in which one or more substances is converted into another by combination or decomposition.
Reactions can be of different types as follows:
AdditionEliminationSubstitutionCondensationHowever, addition and elimination reactions are reverse of one another because addition involves adding substances while elimination involves removing substances.
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pleae help me I'm so confused
What is the velocity of a person that runs 40 km in 100 hours?
Answer:
0.4 km/h velocity is also the direction their going, in this case the person, that I'll name billy bob joe, is going in so yeh
Explanation:
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how does a diaphragm help in viewing the specimen in a microscope
Answer:
Diaphragm controls the amount of light reaching the specimen. It is located above the condenser and below the stage. Most high quality microscopes include an Abbe condenser with an iris diaphragm. Combined, they control both the focus and quantity of light applied to the specimen.
If you were to descend through the ocean in a submersible, what changes in the ocean water could you observe?
Answer:
it would become darker. there would be a higher level of water pressure. and there would be less animals, or different alimals.
Explain why the answer is correct and why the others aren’t.
Pleaseeee
Answer:
Buffalo and Watertown.
Explanation:
This is correct as the Interior lowlands are located ib the US. These are correct as the others are in the US but aren't located anywhere near the Interior Lowlands.
can we seperate naphthalene from sugar by filtration to obtain pure sugar?
Answer:
As Naphthalene undergoes sublimation, we use sublimation process. On condensing naphthalene can be separated.
Between carbon and silicon, which element has the strongest attraction between its nucleus and its valence electrons? Explain?
Answer:
Between carbon and silicon, silicon element has the strongest attraction between its nucleus and its valence electrons.
because silicon's nucleus is bigger than carbon.silicon loses electrons easily than carbon.