Answer:
I need more context. Maybe add a picture.
Explanation:
Answer:
Crown B
Explanation:
because the density of gold is 19.3 and the density of the crown is 19.29.
liquid containing a mixture of neon and xenon was cooled down. One gas solidified at -249 °C and the other at –112 °C. Identify which noble gas solidified at -249 °C and which at -112 °C. Justify your answer.
Answer:
The noble gases (Group 18) are located in the far right of the periodic table and were previously referred to as the "inert gases" due to the fact that their filled valence shells (octets) make them extremely nonreactive. The noble gases were characterized relatively late compared to other element groups.
The History
The first person to discover the noble gases was Henry Cavendish in the late 180th century. Cavendish distinguished these elements by chemically removing all oxygen and nitrogen from a container of air. The nitrogen was oxidized to NO2 by electric discharges and absorbed by a sodium hydroxide solution. The remaining oxygen was then removed from the mixture with an absorber. The experiment revealed that 1/120 of the gas volume remained un-reacted in the receptacle. The second person to isolate, but not typify, them was William Francis (1855-1925). Francis noted the formation of gas while dissolving uranium minerals in acid.
Argon
In 1894, John William Strutt discovered that chemically-obtained pure nitrogen was less dense than the nitrogen isolated from air samples. From this breakthrough, he concluded that another, unknown gas was present in the air. With the aid of William Ramsay, Strutt managed to replicate and modify Cavendish's experiment to better understand the inert component of air in his original experiment. The researchers' procedure differed from the Cavendish procedure: they removed the oxygen by reacting it with copper, and removed the nitrogen in a reaction with magnesium. The remaining gas was properly characterized and the new element was named "argon," which originates from the Greek word for "inert."
Helium
Helium was first discovered in 1868, manifesting itself in the solar spectrum as a bright yellow line with a wavelength of 587.49 nanometers. This discovery was made by Pierre Jansen. Jansen initially assumed it was a sodium line. However, later studies by Sir William Ramsay (who isolated helium on Earth by treating a variety of rare elements with acids) confirmed that the bright yellow line from his experiment matched up with that in the spectrum of the sun. From this, British physicist William Crookes identified the element as helium.
Neon, Krypton, Xenon
These three noble gases were discovered by Morris W. Travers and Sir William Ramsay in 1898. Ramsay discovered neon by chilling a sample of the air to a liquid phase, warming the liquid, and capturing the gases as they boiled off. Krypton and xenon were also discovered through this process.
Radon
In 1900, while studying the decay chain of radium, Friedrich Earns Dorn discovered the last gas in Group 18: radon. In his experiments, Dorn noticed that radium compounds emanated radioactive gas. This gas was originally named niton after the Latin word for shining, "nitens". In 1923, the International Committee for Chemical Elements and International Union of Pure Applied Chemistry (IUPAC) decided to name the element radon. All isotopes of radon are radioactive. Radon-222 has the longest half-life at less than 4 days, and is an alpha-decay product of Radium-226 (part of the U-238 to Pb-206 radioactive decay chain).
The Electron Configurations for Noble Gases
Helium 1s2
Neon [He] 2s2 2p6
Argon [Ne] 3s2 3p6
Krypton [Ar] 3d10 4s2 4p6
Xenon [Kr] 4d10 5s2 5p6
Radon [Xe] 4f14 5d10 6s2 6p
Explanation:
Why aren’t two hydrogen atoms bonded together considered a compound? Explain.
Answer:
Hydrogen gas (H2) is a molecule, but not a compound because it is made of only one element. Water (H2O) can be called a molecule or a compound because it is made of hydrogen (H) and oxygen (O) atoms. There are two main types of chemical bonds that hold atoms together: covalent and ionic/electrovalent bonds.
4.5 tons → lbs
4.5 tons equals how many pounds
Answer:
9000 pounds
Explanation:
9000 pounds
Answer: 9000 lbs.
Explanation: 4.5 tons = 9000 pounds.
A 7.27-gram sample of a compound is dissolved in 250. grams of benzene. The freezing point of this solution is 1.02°C below that of pure benzene. What is the molar mass of this compound? (Note: Kf for benzene = 5.12°C/m.) Ignore significant figures for this problem. Group of answer choices 36.5 g/mol 146 g/mol 292 g/mol 5.79 g/mol 73.0 g/mol
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
How do weathering and deposition differ? (4 points)
оа
Weathering breaks down rocks; deposition leaves them in new places.
Ob
Weathering has to do with air; deposition has to do with plants.
Ос
Weathering occurs only in summer; deposition occurs year-round.
Od
Weathering can be chemical or physical; deposition is only chemical.
Answer:
Oa. Weathering breaks down rocks; deposition leaves them in new places.
Explanation:
Did test and got it right.
A sample of propane, C3H8, contains 13.8 moles of carbon atoms. How many total moles of atoms does the sample contain
Answer:
[tex]Total = 50.6\ moles[/tex]
Explanation:
Given
[tex]Propane = C_3H_8[/tex]
Represent Carbon with C and Hydrogen with H
[tex]C = 13.8[/tex]
Required
Determine the total moles
First, we need to represent propane as a ratio
[tex]C_3H_8[/tex] implies
[tex]C:H = 3:8[/tex]
So, we're to first solve for H when [tex]C = 13.8[/tex]
Substitute 13.8 for C
[tex]13.8 : H = 3 : 8[/tex]
Convert to fraction
[tex]\frac{13.8}{H} = \frac{3}{8}[/tex]
Cross Multiply
[tex]3 * H = 13.8 * 8[/tex]
[tex]3 H = 110.4[/tex]
Solve for H
[tex]H = 110.4/3[/tex]
[tex]H = 36.8[/tex]
So, when
[tex]C = 13.8[/tex]
[tex]H = 36.8[/tex]
[tex]Total = C + H[/tex]
[tex]Total = 13.8 + 36.8[/tex]
[tex]Total = 50.6\ moles[/tex]
The equilibrium constant _____________. For an ___________ reaction, heat is a reactant. An increase in temperature and heat favors the ____________ reaction and the value of K c _____________.
Answer:
The equilibrium constant change. For an endothermic reaction, heat is a reactant. An increase in temperature and heat favors the forward reaction and the value of Kc increases.
Explanation:
Hello.
In this case, regarding reactions in equilibrium in which heat is a reactant as those exemplified by:
[tex]Heat+Reactants \rightleftharpoons Products[/tex]
We infer that the heat of reaction is positive since the reactants have more energy in their ground state than the products making them endothermic. Moreover, since the Le' Chatelier's principle states that increasing the reaction temperature in endothermic reactions, the forward reaction (towards products) is favored because endothermic reactions absorb heat in the form temperature raise, the required statement is:
The equilibrium constant change. For an endothermic reaction, heat is a reactant. An increase in temperature and heat favors the forward reaction and the value of Kc increases.
Regards.
Answer:
The equilibrium constant increases. For an endothermic reaction heat is a reactant. An increase in temperature and heat favours the forward reaction and the value of KC increases.
Explanation:
How many grams of Cl are in 31.2g CF2Cl2
Answer:
Mass = 42.6 g
Explanation:
Given data:
Mass of CF₂Cl₂ = 31.2 g
Mass of Cl₂ = ?
Solution:
Number of moles of CF₂Cl₂ = mass/molar mass
Number of moles = 31.2 g/121 gmol
Number of moles = 0.3 mol
1 mole of CF₂Cl₂ contain 2 moles of Cl atom.
0.3 mol × 2 = 0.6 mol
Mass of Cl₂:
Mass = number of moles × molar mass
Mass = 0.6 mol × 71 g/mol
Mass = 42.6 g
How many milliliters of 10.7 M perchloric acid solution should be used to prepare 5.50 L of 0.200 M
Answer:
102.8 mL.
Explanation:
From the question given above, the following data were obtained:
Molarity of stock solution (M1) = 10.7 M
Molarity of diluted solution (M2) = 0.2 M
Volume of diluted solution (V2) = 5.5 L
Volume of stock solution needed (V1) =.?
The volume of the stock solution needed can be obtained by using the following formula:
M1V1 = M2V2
10.7 × V2 = 0.2 × 5.5
10.7 × V2 = 1.1
Divide both side by 10.7
V2 = 1.1 / 10.7
V2 = 0.1028 L
Finally, we shall convert 0.1028 L to millilitres (mL) in order to obtain the desired result. This can be obtained as follow:
1 L = 1000 mL
Therefore,
0.1028 L = 0.1028 L × 1000 mL / 1 L
0.1028 L = 102.8 mL
Therefore, 0.1028 L is equivalent to 102.8 mL.
Thus, 102.8 mL of the stock solution (i.e perchloric acid) is needed.
PLEASE HELP!!
There are 5.5 L of a gas present at -38.0 C. What is the temperature if the volume of the gas has changed to 1.30 L?
Answer:
The answer is 55.54 KExplanation:
In order to find out the final temperature we use the formula for Charles's law which is
[tex] \frac{V_1}{T_1} = \frac{V_2}{T_2} \\ [/tex]
where
V1 is the initial volume
T1 is the initial temperature in Kelvin
V2 is the final volume
T2 is the final temperature in Kelvin
Since we are finding the final temperature
[tex]T_2 = \frac{V_2T_1}{V_1} \\ [/tex]
rom the question
V1 = 5.5 L
T1 = -38°C = -38 + 273 = 235 K
V2 = 1.30 L
We have
[tex]T_2 = \frac{1.30 \times 235}{5.5} = \frac{305.5}{5.5} \\ = 55.545454...[/tex]
We have the final answer as
55.54 KHope this helps you
Which is an example of a current research focus in chemistry?
A. applying gene therapy to treat certain diseases
B. using hook-and-loop tape in the clothing industry
C. developing smoke detectors for common use
D. studying coal combustion as an energy source
Answer:
b is the correct answer
do not trust answer one
Explanation:
How many atoms are in caco4
Answer: 6
Explanation:
If an atom has a neutral charge, it must have
Answer:
Proton or electron. I think, not sure.
Explanation:
A proton and an electron have an equal amount but an opposite type of charge. Thus, if an atom contains equal numbers of protons and electrons, the atom is described as being electrically neutral.
eletrons I'm pretty sure
Similar properties recur periodically when elements are arranged according to increasing atomic number is the statement of the ______. g
Answer:
Modern periodic law
Explanation:
There are many ways of stating the modern periodic law. Generally, the modern periodic law states that the properties of elements are a periodic function of their atomic numbers. That means, similar properties recur periodically when elements are arranged according to increasing atomic number.
Two scientists were largely responsible for our present day understanding of the modern periodic law, they are, Mendeleev and Moseley. Their work laid the foundation for the periodic table in its current form.
how many moles of h2 can be made from the complete reaction of 3.5 moles of al?
Given: 2Al+6HCL 2Alcl3+3h2
Answer:
From the given equation, we can see that for every 2 moles of Al, we get 3 moles of H2
So, we can say the the number of moles of H2 is 3/2 times the number of moles of Al
We are given the number of moles of Al and we have to find the number of moles of H2
We have deduced the relationship:
Moles of Al * 3 / 2 = Moles of H2
Replacing the variables with given values
3.5 * 3 / 2 = Moles of H2
Moles of H2 = 5.25 moles
Our universe is made up of at least a
The equilibrium constant for A + 2B → 3C is 2.1 * 10^-6
Determine the equilibrium constant for 2A + 4B → 6C.
a- 4.2 * 10^-6
b- 4.4 * 10^-12
c- 2.3 *10^11
d- 1.8 *10^-11
e- None of these
Answer:
b- 4.4 * 10^-12.
Explanation:
Hello.
In this case, as the reaction:
A + 2B → 3C
Has an equilibrium expression of:
[tex]K_1=\frac{[C]^3}{[A][B]^2}=2.1x10^{-6}[/tex]
If we analyze the reaction:
2A + 4B → 6C
Which is twice the initial one, the equilibrium expression is:
[tex]K_2=\frac{[C]^6}{[A]^2[B]^4}[/tex]
It means that the equilibrium constant of the second reaction is equal to the equilibrium constant of the first reaction powered to second power:
[tex]K_2=K_1^2[/tex]
Thus, the equilibrium constant of the second reaction turns out:
[tex]K_2=(2.1 * 10^{-6})^2\\\\K_2=4.4x10^{-12}[/tex]
Therefore, the answer is b- 4.4 * 10^-12.
Best regards.
Forty milliliter of a liquid has a mass of 80 grams. What is the density of this substance?
Answer:
2.00g/ml
Explanation:
If water has a density of 1.00g/ml, and theres
40ml of it, it would weigh 40g
The substance is twice as dense as water, making its density 2.00g/ml
5. What gases was produced from decomposing hydrogen peroxide? What non-gaseous product formed from the reaction
Answer:
H2O
Explanation:
The equation for the decomposition of hydrogen peroxide is shown below;
2H2O2(l)-----> 2H2O(l) + O2(g)
Hence, the decomposition of H2O2 yields oxygen gas and water. Water is a non gaseous product of the reaction as clearly seen in the equation above.
Answer each of the following questions with increases, decreases, or does not change.
a) If the intermolecular forces in a liquid increase, the normal boiling point of the liquid increases .
b) If the intermolecular forces in a liquid increase, the vapor pressure of the liquid does not change .
c) If the surface area of a liquid increases, the vapor pressure increases .
d) If the temperature of a liquid decreases, the equilibrium vapor pressure increases .
Drag and drop your selection from the following list to complete the answer:
does not change decreases increases
Answer:
a) increases
b) decreases
c) does not change
d) increases
Explanation:
The vapour pressure of a liquid is dependent on;
I) the magnitude of intermolecular forces
II) the temperature of the liquid
Hence, when any of these increases, the vapour pressure increases likewise.
Similarly, the boiling point of a liquid depends on the magnitude of intermolecular forces present because as intermolecular forces increases, more energy is required to break intermolecular bonds.
Lastly, increase in surface area of a liquid does not really affect it's vapour pressure.
Using charge to describe an atom
Answer:
this atom has nine electrons
is a renewable resource used for the generation of electricity.
A. Natural gas
B. Coal
C. Petroleum
O D. Biomass
Answer:
its natural gas because i had something like this
Explanation:
The renewable energy sources, such as biomass, geothermal resources, water, wind, etc. are called the natural resources. These can be converted into clean and usable energy. The correct option is D.
What is Renewable energy?The energy which is derived from the natural sources which are replenished at a higher rate than they are consumed is defined as the Renewable energy. The renewable energy generating produce lower emissions than burning the fossil fuels.
The word biomass refers to the organic plant matter which is converted into fuel and used as an energy source. The biomass fuel is considered as an important renewable and sustainable source of energy. It is used for the production of electricity.
The organic materials like wood, agricultural wastes, etc. acts as the excellent sources to produce biomass fuel. It is possible to burn the biomass fuel directly and later converted into methane and ethanol biofuels.
Thus the correct option is D.
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All good experiments should be...
Solid calcium chlorate decomposes to form solid calcium chloride and oxygen gas.
Write the balanced chemical equation for the reaction described. Phases are optional.
equation:
Answer:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Explanation:
Chemical equation:
Ca(ClO₃)₂(s) → CaCl₂(s) + O₂(g)
Balance chemical equation:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Step 1:
Ca(ClO₃)₂(s) → CaCl₂(s) + O₂(g)
Left hand side Right hand side
Ca = 1 Ca = 1
Cl = 2 Cl = 2
O = 6 O = 2
Step 2:
Ca(ClO₃)₂(s) → CaCl₂(s) + 3O₂(g)
Left hand side Right hand side
Ca = 1 Ca = 1
Cl = 2 Cl = 2
O = 6 O = 6
Explain how a hurricane poses a threat to life and the biosphere. Use complete sentences.
Answer:
A hurricane can cause extreme damage to the biosphere and the geosphere. A hurricane can leave water standing therefore sinking itself into the geosphere. The biosphere can be permanently effected because it can kill, injure, and destroy the biosphere and what the biosphere creates (buildings, parks).
Explanation:
where in water is being converted into a gaseous form?
evaporation
condensation
transportation
precipitation
Answer:
It's called Evaporation.
Draw molecules that satisfy the following prompts:
1. All molecules must have a minimum of 12 Carbon atoms and exactly 3 heteroatoms (not carbon or hydrogen atoms).
2. You may not use the same molecule twice for any parts of this question.
4. You do not need to look up solubility information, but the answers must be reasonable (supported by the concepts that we have discussed). Also, the structures must be reasonable (improper structures, e.g. carbon with 5 bonds or oxygen with one bond and no charge, will not receive any credit).
a. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M HCl(aq) and dichloromethane.
b. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M NaOH(aq) and dichloromethane.
c. Draw two non-charged molecules that will be separated using neutral water and dichloromethane and in a separatory funnel.
Answer:
see images attached
Explanation:
Here we are trying to perform solvent extraction. In solvent extraction, there must be an aqueous phase and an organic phase.
One of the species to be separated is extracted in greater concentration in the aqueous phase while the other is extracted in greater concentration in the organic phase.
The phase into which each specie is extracted depends on the nature of the specie.
Two structures are shown in the images attached that will be separated by the methods shown in (a) (b) (c) in the question
Balance the equations by inserting coefficients as needed.
equation 1:
CaCO3 + HCl -> CaCl2 + CO2 + H2O
CaCO3+HCl⟶CaCl2+CO2+H2O
equation 2:
C6H12O2 + O2 -> CO2 + H2O
C6H12O2+O2⟶CO2+H2O
Answer:
1. CaCO3 + 2HCl → CaCl2 + H2O + CO2
2. C6H12O2 + 8O2 → 6CO2 + 6H2O
Explanation:
The balanced chemical equation is (i) CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+ 8O2⟶CO2+6H2O
What is balanced chemical equation?An equation with equal amounts of every atom of an element on both endpoints of the arrow was called a balanced equation.
Given chemical equation is:
(i) CaCO3+HCl⟶CaCl2+CO2+H2O
It can be seen that in left side of the chemical equation count of chlorine atom is one while right side of the chemical equation it is two. So, by multiplying 2 as a coefficient in the right side of the equation. Balanced chemical equation will be
CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+O2⟶CO2+H2O
It can be seen that, there are 12 hydrogen in the left side of the reaction while it is two hydrogen in the right side of the reaction. By multiplying 6 as a coefficient of hydrogen. Hence, the balanced chemical equation will be
C6H12O2+ 8O2⟶CO2+6H2O
The balanced chemical equation is
(i) CaCO3+2HCl⟶CaCl2+CO2+H2O
(ii) C6H12O2+ 8O2⟶CO2+6H2O
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Which of these is the best definition of biotechnology??
A) The study of chemical processes in living things
B) the use and application of living things and science
C) the application of engineering principles to solve medical problems
D) the study of forces
Use the periodic table to identify the chemical symbol or name for each element below.
zirconium:
zr
rhenium:
re
: As
: K
tin:
yttrium:
: Yb
Answer:
zirconium is Zr
rhenium is Re
As is arsenic
K is potassium
tin is Sn
yttrium is Y
ytterbium is Yb
Explanation:
With the help of the periodic table, the identification of the chemical symbol or name for each element is represented as follows:
Zirconium: Zr. Rhenium: Re. Arsenic: As.Potassium: K.Tin: Sn. Yttrium: Y. Ytterbium: Yb. What are the chemical elements?Chemical elements may be defined as any type of substance that cannot be further decomposed into simpler substances through the utilization of other ordinary chemical processes or external factors. These elements possess specific physical as well as chemical properties distinctly.
In the modern periodic table, each element is arranged on the basis of its increasing atomic number. Each element possesses its unique symbol, atomic mass, and physical properties like boiling points, melting points, density, etc.
Therefore, with the help of the periodic table, the identification of the chemical symbol or name for each element is well represented above.
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