102. What is the Pauli exclusion principle? What is Hund's rule?
Pauli Exclusion Principle is about quantum numbers of an atom. Hund rule is about how electrons are filled to the orbitals of an atom.
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Answer:
The molar mass of O is 16 g/mol and since we have 2 oxygen molecules we multiply 16 g/mol to get 32 g/mol. Therefore our best option would be option C, 32 g/mol.
WILL MARK BRAINLIST!! A chemist weighs a steel cylinder of compressed oxygen, O2, and finds that it has a mass of 1027.8 g. After some of the oxygen is used in an experiment, the cylinder has a mass of 1023.2 g. How many moles of oxygen gas are used in the experiment?
When answering this question include the following:
Explain how you found the mass of oxygen gas.
Explain how to find the molar mass of the compound.
Explain how many significant figures your answer needs to have.
The numerical answer
Answer:
0.14376 moles O₂
Explanation:
To find the amount of moles lost, (1) convert the grams O₂ before to moles (via molar mass from periodic table), then (2) convert the grams O₂ after to moles, then (3) subtract the moles O₂ after from the moles O₂ before.
Molar Mass (O₂) = 2(15.999) g/mol
Molar Mass (O₂) = 31.998 g/mol
Before Experiment:
1,027.8 grams O₂ 1 mole O₂
-------------------------- x ---------------------- = 32.121 moles O₂
31.998 grams
After Experiment:
1,023.2 grams O₂ 1 mole O₂
-------------------------- x ---------------------- = 31.977 moles O₂
31.998 grams
Moles Before - Moles After = Moles Lost
32.121 moles - 31.977 moles = 0.14376 moles O₂
The number of significant figures is determined by the significant figures of the values given. Both of the given values (1,027.8 and 1,023.2) have 5 sig figs. Therefore, the answer should also have 5 sig figs.
What mass loss would you expect from a reaction between 10.04g of calcium carbonate and 20cm3 of 1m hydrochloric acid
Based on the law of conservation of mass, there is no loss in mass in the reaction, however carbon dioxide gas is evolved.
What is the law of conservation of mass?The law of conservation of mass states that for a chemical change occurring, the sum of masses before and after the reaction is constant.
Based on the law of conservation of mass, the reaction between 10.04g of calcium carbonate and 20cm3 of 1m hydrochloric acid will have the same mass before and after the reaction. Any change in mass will be due to evolution of carbon dioxide gas.
Therefore, there is no loss in mass in the reaction, however carbon dioxide gas is evolved.
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Chemistry
Bellringer: Find the mass of 5.78 moles of carbon
dioxide.
Answer:
254.32
Explanation:
The formula to calculate mass is:
no. of moles ×molar mass. and the molar mass of carbon dioxide is 44
Which is true about distillation? (1 point)
It uses semipermeable membranes to filter out particles.
It removes mainly large particulate contaminants which settle to the bottom.
It is one of the easiest and cheapest filtration solutions to implement.
It may leave some chemicals such as herbicides and pesticides in the water.
Answer:
It may leave some chemicals such as herbicides and pesticides in the water
Explanation:
i just took the test
Distillation may leave some chemicals such as herbicides and pesticides in the water. Therefore, option D is correct.
What is distillation ?By using selective boiling and condensation, distillation, also known as traditional distillation, is the process of removing the constituents or compounds from a liquid mixture. The process of heating solid materials to create gaseous products is known as dry distillation.
A chemical is purified through distillation by being separated from a non-volatile or less-volatile substance. Because various compounds frequently have different boiling points, when a mixture is distilled, the components frequently separate from the mixture.
Among the many industrial uses of distillation are the production of alcoholic drinks, water purification, and oil refining. Distillation is a physical procedure that removes desired pure compounds from an initial source using heat and other techniques.
Thus, option D is correct.
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what volume of O2, collected at 22.0C and 0.958 atm would be produced by the decomposition of 8.15g KClo3?
2KClO3(s)-----2KCl(s)+3)2(g)
Answer:
a
Explanation:
Pure water consists of 11. 19% hydrogen by weight and 88. 81% oxygen by weight. what does the law of constant proportions tell you about a 100 g sample of pure water?
Answer:
The law of constant proportion states that the percentage of each compound will stay constant regardless of the source size.
In other words, since 11.19% + 88.81% = 100%, in a 100 gram sample, these percentages will stay the same. In this case, 100% is "equal" to 100 grams.
So, 11.19 grams hydrogen and 88.81 grams oxygen will be present in a 100 gram sample of pure water.
why would solution iv be considered the most concentrated base out of the four substances?
Acids and bases are the property of the solution based on the concentration of the ions. Solution IV is the most concentrated base as it has the highest concentration of hydroxide ions.
What are bases?Bases are substances or solution that has the potential of hydrogen above 7 on the pH meter scale. It has more hydroxide ions than hydronium or hydrogen ions.
The higher the hydroxide concentration lower will be the pOH and the more alkaline will be the solution. The hydroxide ions have more electrons and can donate some to other species.
Therefore, solution IV is a concentrated base because of high hydroxide ion concentrations.
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Organic compounds form the basis of?
A Carbon
B Life
C Water
Answer:
A Carbon
Explanation:
Why knowing the density of water important to humans or society?
Answer:
it allows us to determine what substances will float and what substances will sink when placed in a liquid.
Mix two liquids together and shake them up. You see that you have microscopic droplets of one liquid suspended in the other. You would call this:
Answer:
The awnser is cloudy suspension.
As the microscopic droplets of one liquid are suspended in the other, it is a heterogeneous mixtures.
What are heterogeneous mixtures?
Heterogenous mixtures is defined as a type of mixture where in the composition is not uniform throughout the mixture.It consists as two or more phases. The phases are chemically distinct from each other.
As there are two or more phases present in heterogenous mixtures they can be separated by solvent extraction where in one phase is miscible with the solvent and the other phase is immiscible.
Components of a heterogenous mixtures are distinctly visible . There are two types of heterogenous mixtures, the colloids and the suspensions.These two vary with each other with respect to particle size.These are the mixture which are easy to separate out.
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The diagram below shows two substances. What name is given to bond X?
Answer:
single covalent bond
Explanation:
The bond formed between two atoms each sharing one electron is called single covalent bond
The figure 1 is the structure of diamond. The type of bond in diamond is covalent sp³ bond. DIamond exists in hexagonal arrangement of carbon atoms.
What is allotrope?Allotropes are substances formed from a single elements with different number in various size and shape. Carbon exhibit catenation property which means it can forms chains with other carbon in any large number.
The allotropes of carbon are diamond, graphene and fullerene. Diamond is hexagonal arrangement of carbons atom bonded covalently in sp³ hybridisation.
In graphene as shown in the second figure, bonded carbons atoms are arranged as layers where carbon is in sp²hybridisation. In the case of fullerenes, there are both hexagonal and pentagonal rings adjacent to each and are formed by 60-70 carbons.
In all these allotropes, the bond type between two carbons atoms is covalent. Covalent bond is formed by sharing of electrons between the two atoms.
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What is the ph of a 0.00043 molar solution of lithium hydroxide (lioh)?
Answer:
pH = 10.63.
Explanation:
Recall that lithium hydroxide (LiOH) is a strong base and hence dissociates completely into Li⁺ and OH⁻ ions.
Therefore, the concentration of OH⁻ ions is equivalent to the concentration of the base.
Find pOH:
[tex]\displaystyle \begin{aligned} \text{pOH} & = -\log[\text{OH}^-] \\ \\ & = -\log(0.00043) \\ \\ & = 3.37 \end{aligned}[/tex]
Using the relationships between pH and pOH, hence determine pH:
[tex]\displaystyle \begin{aligned}\text{pH} + \text{pOH} & = \text{p}K_w = 14.00 \\ \\ \text{pH} & = 14.00 - 3.37 \\ \\ & = 10.63\end{aligned}[/tex]
In conclusion, the pH of the solution is about 10.63.
On Earth, carbon is essential to life. Where did Earth get its carbon?
Answer: Most of Earth's carbon was inherited directly from the interstellar medium, it is the material that exists in space between stars in a galaxy.
Explanation: All of the carbon and oxygen in all living things are made in the nuclear fusion reactors that we call stars. The early stars are massive and short-lived. They consume hydrogen, helium, and lithium and produce heavier elements.
Hope this helps!
Name these compounds according to IUPAC.
The name of the compound CH₃CHOOH is acetic acid.
What is IUPAC naming rules?The International Union of Pure and Applied Chemistry (IUPAC) names organic compounds according to chemistry rules.
To locate the longest carbon chain, there are various requirements to follow, such as finding the functional group.
Thus, the name of the compound CH₃CHOOH is acetic acid.
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An atom was observed with +3 charge, n = 38, and e = 28. What is the mass number of the atom?
A. 66
B. 69
C. 72
D. 63
Answer: 66
Explanation: To find the mass number you would have to add the number of protons and the number of neutrons.
Which of the following is Not a physical change?
A. Grating cheese
B. Melting cheese
C. Fermenting cheese
D. Mixing two cheeses in a bowl
Answer:
c: fermenting of cheese
Answer:
c
Explanation:
Does the amount of water affect the growth of a plant?
Answer:
Yes
Explanation:
It does because of the fact that plants need water to live and the grow. Water helps the plant grow, and certain plants would need less or more water based on their roots, leaves, and tempurature tolerancy.
Answer: Yes,
Roots need both water and oxygen, and when surrounded by water, they cannot take up oxygen. Plants may slow in growth after a flush of new growth or a heavy flowering. During these periods and while it is dormant, a plant will need less water.
Which of the following is true for a system at equilibrium?
Option 1- the rates of the forward and reverse reactions are equal, or option 2-The reactants have been completely used up?
Answer:
option 1
Explanation:
you can never have all your reactants used up coz it is not possible eg in space u only loose SOme of gravity
a solution contains 2 moles of hydrochloric acid.the volume of the solution is 250 cm3
what is its concentration in mol/dm³
Answer:
1dm = 10cm
1dm3 = 10cm x 10cm x 10cm = 1000cm3
1L = 1000cm3
so 1litre = 1dm3
4 moles in 2 dm3
= 2 moles in 1dm3 = 2moles in 1L = 2M
1L = 1000cm
0.3 moles in 200cm3 =
200cm3 = 0.2L
so 0.3 moles in 0.2 L = 1.5 moles in 1 L = 1.5M
(I have tried to simplify and show why 1dm3 = 1L)
I hope this helps you understand!
1 start with 25°C and a volume of 10.0L. If I increase the volume to 15.0L, what is my new temperature? (Equation that is helpful: K= 273 + "C)
Answer:
If in volume of 10.0L it is 25°C than it will be 37.5C volume in the new temperature if increased from 10.0L to 15.0L
Explanation:
10.0L=25°C
15.0L=?
10×2.5= 25
15×2.5=37.5
Kelvin(K)= C+273=T
=37.5+275=312.5
=C=312.5-275
=C=37.5
A student mixed two chemicals to allow them to
react. The temperature before the reaction was 25
°C. The temperature after the reaction was 50° C.
Which of the following is true?
A. there was no change in heat energy
B. it is an exothermic reaction
help plsssss
Answer:
B .it is an exothermic reaction
Explanation:
i need brainleyest
Fill in the blank with the correct response.
————— surveys are measurement tools that use a series of questions to obtain data from respondents.
Surveys are the data collection tool and research methods. The questionnaire survey tool is used to collect the data based on questions.
What are questionnaires?Questionnaires are the tool used for the research and the data collection for the analysis, investigation, and conclusion. It is one of the data collection tools that comprises questions and prompts.
Questionnaires are the part of surveys that gathers information on the topic of the research and is easy to analyze and cost-effective. It is a valuable tool that collects data from a large number of participants.
Therefore, the correct blank is the questionnaire.
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balanced symbol equation for the following:
magnesium hydroxide + nitric acid → magnesium nitrate + water
[tex]\text{Mg(OH)}_2 + 2\text{HNO}_3 \rightarrow \text{Mg(NO}_3)_2+ 2\text{H}_2 \text{O}[/tex]
What is the purpose of cross breeding or selective breeding
Which of the following is an example of a chemical property of matter that can be observed?
Weight
Temperature
Flammability
Breaking glass
True or false? Ionic compounds are usually a combination of a metal and a non-metal.
Answer:
here down below is the anwser
Explanation:
Whereas ionic compounds are usually formed when a metal and a nonmetal combine, covalent compounds are usually formed by a combination of nonmetals. Thus, the periodic table can help us recognize many of the compounds that are covalent.
Identify the balanced chemical equation that represents a decomposition reaction.
2Fe(OH) 3 ⟶ 2FeO 3 + H 2O
CuSO 4 ⟶ CuO + 2SO 3
2Fe(OH) 3 ⟶ Fe 2O 3 + 3H 2O
P 4 + 3O 2 ⟶ P 2O 3
Identify the balanced chemical equation that represents a decomposition reaction.
2Fe(OH) 3 ⟶ 2FeO 3 + H 2O
CuSO 4 ⟶ CuO + 2SO 3
2Fe(OH) 3 ⟶ Fe 2O 3 + 3H 2OP 4 + 3O 2 ⟶ P 2O 3
Explanation:
Answer:
Option C
Explanation:
A decomposition reaction is a type of reaction in which one reactant breaks down in to two or more products.
Here in option C
On both reactant and products side
Fe=2O=6H=6Hence balanced
The reaction between bromine and methylpropene is an electrophilic addition. Describe .with the aid of curly arrows ,the mechanism of the reaction. Show that the intermediate and the product along with any dipoles and and lone pair of electron.
Electrophillic addition occurs when the substrate has a double bond and the attacking agent is a electrophile.
What is electrophillic addition?The term electrophillic addition refers to a type of addition that occurs when the substrate has a double bond and the attacking agent is a electrophile.
The mechanism of the electrophillic attack on methyl propene as shown indicates that the attacking agent is an electrophile(Br^+).
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