Answer:
1.69 g Na₂O
General Formulas and Concepts:
Chemistry - Atomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:
Step 1: Define
0.0273 mol Na₂O
Step 2: Identify Conversions
Molar Mass of Na - 22.99 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of Na₂O - 2(22.99) + 16.00 = 61.98 g/mol
Step 3: Convert
[tex]0.0273 \ mol \ Na_2O(\frac{61.98 \ g \ Na_2O}{1 \ mol \ Na_2O} )[/tex] = 1.69205 g Na₂O
Step 4: Check
We are given 3 sig figs. Follow sig fig rules and round.
1.69205 g Na₂O ≈ 1.69 g Na₂O
The enthalpy change of formation of carbon dioxide is –394 kJ mol–1. The enthalpy change of formation of water is –286 kJ mol–1. The enthalpy change of formation of methane is –74 kJ mol–1. What is the enthalpy change of combustion of methane?
The enthalpy change of combustion of methane : -892 kJ/mol
Further explanationThe change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation
The enthalpy of formation measured in standard conditions (25 ° C, 1 atm) is called the standard enthalpy of formation (ΔHf °)
Determination of the enthalpy of formation of a reaction can be through a calorimetric experiment, based on the principle of Hess's Law, enthalpy of formation table, or from bond energy data
The value of ° H ° can be calculated from the change in enthalpy of standard formation:
∆H ° rxn = ∑n ∆Hf ° (product) - ∑n ∆Hf ° (reactants)
Reaction for combustion of Methane (CH₄) :
CH₄ + 2O₂ → CO₂ + 2H₂O.
The elements in standard conditions are not included in the enthalpy calculations because the enthalpy of those elements under the standard conditions is zero(∆Hf °O₂ =0)
∆Hf ° CO₂ = -394 kj/mol
∆Hf ° H₂O=-286 kj/mol
∆Hf ° CH₄=-74 kJ/mol
The enthalpy change of combustion of methane :
[tex]\tt \Delta H_{rxn}=\Delta H_f~CO_2+2.\Delta H_fH_2O-(\Delta H_fCH_4)\\\\\Delta H_{rxn}=(-394-2.-286)-(-74)\\\\\Delta H_{rxn}=-892~kJ/mol[/tex]
Answer:
-655
Explanation:
ye
How many moles are present in a 5.8 g sample of copper?
A. 11
B. 0.091
C. 0.91
D. 5.5 x 10^22
please i need this for my finals
Explanation:
Molar mass of Cu = 63.5g/mol
Moles of Cu
= 5.8g / (63.5g/mol) = 0.091mol (B)
The number of moles present in a 5.8 g sample of copper is equal to 0.0913 mol. Therefore, option B is correct.
What is a mole?A mole can be defined as an international scientific unit that is used to determine for given count of particles. The particles are commonly identical entities but they are individually distinct.
A mole of the substance can be used to evaluate a large number of atoms, molecules, or particular particles. The amount of material can be measured as chemical entities of a substance in a sample.
The number of units in 1 mole of a material is equal to 6.023×10²³ which is called Avogadro’s constant.
Given, the mass of the copper = 5.8 g
The mass of one mole of copper = 63.5 g
We can calculate moles as, n = Mass/molar mass
Then, the number of moles of copper = 5.8/63.5 = 0.0913 mol
Therefore, the number of moles of copper is 0.0913 mol.
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Molecules have Question 8 options: A) only kinetic energy. B) neither kinetic nor potential energy. C) only potential energy. D) both potential and kinetic energy.
What is the molarity of a solution made from dissolving 3.0 moles of NaCl in 250 mL of solution?
3.0 M NaCl
0.012 M NaCl
750 M NaCl
12 M NaCl
Answer:
Molarity = 12 M
Explanation:
Given data:
Molarity of solution = ?
Number of moles of NaCl = 3.0 mol
Volume of solution = 250 mL (250/1000 = 0.25 L)
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Molarity = 3.0 mol / 0.25 L
Molarity = 12 M
Answer:
[tex]\boxed {\boxed {\sf 12 \ M \ NaCl}}[/tex]
Explanation:
Molarity, which tells us the concentration of a solution, is found by dividing the moles of solute by the liters of solution.
[tex]M=\frac{moles \ of \ solute}{liters \ of \ solution}[/tex]
1. Define Values
There are 3.0 Moles of NaCl. This is the moles of solute.
There are 250 milliliters of solution, but we need the liters.
a. Convert mL to L
1 milliliter is equal to 0.001 liters. We can multiply the given number of milliliters (250) by 0.001.
250 mL * 0.001 L/mL= 0.25 L
[tex]moles \ of \ solute = 3.0 \ mol \ NaCl \\liters \ of \ solution= 0.25 \ L[/tex]
2. Calculate Molarity
Substitute the values into the formula.
[tex]M=\frac{3.0 \ mol \ NaCl}{0.25 \ L}[/tex]
Divide.
[tex]M= 12 \ mol \ NaCl/L[/tex]
3. Define Units
1 mole per liter is equal to 1 molar.
Our answer of 12 mol NaCl/ L is equal to 12 M NaCl
The molarity is 12 M NaCl
At the cellular level.
blood cells are key in fighting foreign invaders,
O white
O pink
Orainbow
O red
Answer:
the white blood cells are key in fighting foreign invaders.
what are three phases of water
Answer:
Under normal conditions, water exists in one of three phases, the solid phase (ice), the liquid phase (water), and the gaseous phase (steam).
Hope it helps!
In which scenarios would the amount of substance remaining be 200 mg? Select all that apply. 800 mg of a radioactive substance with a half-life of 2 years after decaying for 4 years 1,000 mg of a radioactive substance with a half-life of 5 years after decaying for 20 years 300 mg of a radioactive substance with a half-life of 1 year after decaying for 1 year 600 mg of a radioactive substance with a half-life of 6 hours after decaying for 18 hours 400 mg of a radioactive substance with a half-life of 8 hours after decaying for 8 hours
Answer:
e) 400 mg of a radioactive substance with a half-life of 8 hours after decaying for 8 hours
a) 800 mg of a radioactive substance with a half-life of 2 years after decaying for 4 years.
Explanation:
a) 800 mg of a radioactive substance with a half-life of 2 years after decaying for 4 years.
Number of half lives passed = Time elapsed/ half life
Number of half lives passed = 4 year/2 year
Number of half lives passed = 2
at time zero = 800 mg
At first half life = 800 mg/2 = 400 mg
At 2nd half life = 400 mg/2 = 200 mg
b) 1,000 mg of a radioactive substance with a half-life of 5 years after decaying for 20 years
Number of half lives passed = Time elapsed/ half life
Number of half lives passed = 20 year/ 5 year
Number of half lives passed = 4
at time zero = 1000 mg
At first half life = 1000 mg/2 = 500 mg
At 2nd half life = 500 mg/2 = 250 mg
At 3rd half life = 250 mg/2 = 125 mg
At 4th half life = 125 mg/2 = 62.5 mg
c) 300 mg of a radioactive substance with a half-life of 1 year after decaying for 1 year
Number of half lives passed = Time elapsed/ half life
Number of half lives passed = 1 year/ 1 year
Number of half lives passed = 1
at time zero = 300 mg
At first half life = 300 mg/2 = 150 mg
d) 600 mg of a radioactive substance with a half-life of 6 hours after decaying for 18 hours
Number of half lives passed = Time elapsed/ half life
Number of half lives passed = 18 hours / 6 hours
Number of half lives passed = 3
at time zero = 600 mg
At first half life = 600 mg/2 = 300mg
At 2nd half life = 300 mg/2 = 150 mg
At 3rd half life = 150 mg/2 = 75 mg
e) 400 mg of a radioactive substance with a half-life of 8 hours after decaying for 8 hours
Number of half lives passed = Time elapsed/ half life
Number of half lives passed = 8 hours / 8 hours
Number of half lives passed = 1
at time zero = 400 mg
At first half life = 400 mg/2 = 200 mg
How many grams are 1.2 x 10^-2 moles of K3PO4
Answer:
2.5471951319999997
Explanation:
What happened to the celery if you put in food color water
Answer:
the celery would change colour!
Explanation:
d. Butanol has the chemical formula C4H,OH. Write and balance the chemical reaction for the combustion of butanol.
Answer:
C4H9OH + 6O2 → 4CO2 + 5H2O
Explanation:
What is the final concentration of a hydrogen peroxide solution if 600 mL of a 1.2M solution was diluted to 1.0 L?
Problem #1: If you dilute 175 mL of a 1.6 M solution of LiCl to 1.0 L, determine the new concentration of the solution.
Solution:
M1V1 = M2V2
(1.6 mol/L) (175 mL) = (x) (1000 mL)
x = 0.28 M
Note that 1000 mL was used rather than 1.0 L. Remember to keep the volume units consistent.
Problem #2: You need to make 10.0 L of 1.2 M KNO3. What molarity would the potassium nitrate solution need to be if you were to use only 2.5 L of it?
Solution:
M1V1 = M2V2
(x) (2.5 L) = (1.2 mol/L) (10.0 L)
x = 4.8 M
Please note how I use the molarity unit, mol/L, in the calculation rather than the molarity symbol, M.
Problem #3: How many milliliters of 5.0 M copper(II) sulfate solution must be added to 160 mL of water to achieve a 0.30 M copper(II) sulfate solution?
Solution:
M1V1 = M2V2
(5.00 mol/L) (x) = (0.3 mol/L) (160 + x)
5x = 48 + 0.3x
4.7x = 48
x = 10. mL (to two sig figs)
The solution to this problem assumes that the volumes are additive. That's the '160 + x' that is V2.
Problem #4: What volume of 4.50 M HCl can be made by mixing 5.65 M HCl with 250.0 mL of 3.55 M HCl?
Solution:
Here is the first way to solve this problem:
M1V1 + M2V2 = M3V3
(3.55) (0.250) + (5.65) (x) = (4.50) (0.250 + x)
Where x is volume of 5.65 M HCl that is added
(0.250 + x) is total resultant volume
0.8875 + 5.65x = 1.125 + 4.50 x
1.15x = 0.2375
x= 0.2065 L
Total amount of 4.50 M HCl is then (0.250 + 0.2065) = 0.4565 L
Total amount = 456.5 mL
Here is the second way to solve this problem:
Since the amount of 5.65 M added is not asked for, there is no need to solve for it.
M1V1 + M2V2 = M3V3
(3.55) (250) + (5.65) (x − 250) = (4.50) (x)
That way, x is the answer you want, the final volume of the solution, rather than x being the amount of 5.65 M solution that is added.
Problem #5: A 40.0 mL volume of 1.80 M Fe(NO3)3 is mixed with 21.5 mL of 0.808M Fe(NO3)3 solution. Calculate the molar concentration of the final solution.
what is matter?Give five example.
Question :
what is matter?
Answer:
In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume.[1]:21 All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic particles, and in everyday as well as scientific usage, "matter" generally includes atoms and anything made up of them, and any particles (or combination of particles) that act as if they have both rest mass and volume. However it does not include massless particles such as photons, or other energy phenomena or waves such as light.[1]:21[2] Matter exists in various states (also known as phases). These include classical everyday phases such as solid, liquid, and gas – for example water exists as ice, liquid water, and gaseous steam – but other states are possible, including plasma, Bose–Einstein condensates, fermionic condensates, and quark–gluon plasma.[3]
Usually atoms can be imagined as a nucleus of protons and neutrons, and a surrounding "cloud" of orbiting electrons which "take up space".[4][5] However this is only somewhat correct, because subatomic particles and their properties are governed by their quantum nature, which means they do not act as everyday objects appear to act – they can act like waves as well as particles and they do not have well-defined sizes or positions. In the Standard Model of particle physics, matter is not a fundamental concept because the elementary constituents of atoms are quantum entities which do not have an inherent "size" or "volume" in any everyday sense of the word. Due to the exclusion principle and other fundamental interactions, some "point particles" known as fermions (quarks, leptons), and many composites and atoms, are effectively forced to keep a distance from other particles under everyday conditions; this creates the property of matter which appears to us as matter taking up space.
For much of the history of the natural sciences people have contemplated the exact nature of matter. The idea that matter was built of discrete building blocks, the so-called particulate theory of matter, independently appeared in ancient Greece and ancient India among Buddhists, Hindus and Jains in 1st-millennium BC.[6] Ancient philosophers who proposed the particulate theory of matter include Kanada (c. 6th–century BC or after),[7] Leucippus (~490 BC) and Democritus (~470–380 BC).[8]
Which one is a decomposition reaction?
Answer:
b no
Explanation:
because it is decomposing into two elements
Oxidation of a secondary alcohol results in the formation of a(n):________. a) tertiary alcohol b) acid c) aldehyde d) ketone
Answer:
A. Tertiary alcohol
Explanation:
Secondary alcohols are oxidized to ketones - and that's it. For example, if you heat the secondary alcohol propan-2-ol with sodium or potassium dichromate(VI) solution acidified with dilute Sulphuric acid, you get propanone formed. Playing around with the reaction conditions makes no difference whatsoever to the product.
Medicationswith names ending in ER,CR,XR,and SR indicate they are __ medications a: extended or controlled release b: oral c: chewable d: allergy
Answer: a: extended or controlled release
Explanation:
Which actions can be taken to plan for a drought check all that apply
Answer:
Can you attach a picture?
Explanation:
Which is a type of chemical weathering?
A.
abrasion
B.
condensation
C.
exfoliation
D.
hydration
Answer:
The correct answer is D) hydration
d
Explanation:
the answer is hydration
An unbalanced chemical equation is shown: 2NaN3 → 2Na + N2 Which of the following statements explains why the equation is not balanced? (4 points)
Answer:
When you fill in 2 reactants, you will have 6 N atoms but on the side of the product there are only 2 N atoms, so the equation cannot be balanced and for the equation to be equal, you need to fill 3 into the part N2 to have 6 N atoms
Explanation:
The given reaction unbalanced because of the number of nitrogen is unequal in both side. Three molecules of N₂ should be there in the product side of this decomposition reaction.Thus option C is correct.
What is decomposition reaction?
A decomposition reaction is the one in which a compound decomposes into its constituent compounds or molecules.It is mostly exothermic thus, release heat energy.
In balanced reaction, each elements have to be equal in number in both reactant and product side. The imbalanced reaction can be balanced multiplying with simple intergers.
In the given reaction, sodium is balanced and nitrogen is not. There are 6 nitrogen in the reactant side and only 2 in the product side. Hence, the product side have to multiplied by 3. Hence, Three molecules of N₂ should be produced during the decomposition. Thus, option C is correct.
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Your question is incomplete.But your complete question is as follows:
An unbalanced chemical equation is shown:
2NaN3 → 2Na + N2
Which of the following statements explains why the equation is not balanced?
A. Four molecules of N2 should be produced during the synthesis reaction.
B. Four molecules of N2 should be produced during the decomposition.
C. Three molecules of N2 should be produced during the decomposition.
D. Three molecules of N2 should be produced during the synthesis reaction.
C. Three molecules of N2 should be produced during the decomposition.
Q5. Why are some salts acidic when others are neutral?
Q. The entropy of the system will usually increase when
answer choices
A)a molecule is broken into two or more smaller
molecules
B)a reaction occurs that results in an increase in
the number of moles of gas
C)a solid changes to a liquid
D)all of these
Answer:
D
Explanation:
What is the purpose of the lab for science
Answer:
The lab is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed.
Explanation:
a compound has an empirical formula of C2H303. if its molar mass is 300.20 g, what is its molecular formula?
How many molecules of H2 will react with one molecule of the following triglyceride? CH2-O-C-(CH)14CH CH O-C-(CH)CH CH (CH)-CH CH2-O-C-(CH)16CH a. 1 b.3 c. 4 d. 6
Answer:
1
Explanation:
The full question is shown in the image attached.
If we look at the structure closely, we will discover that there is only one C=C double bond in the molecule.
It is worthy of note that hydrogen (H2) only reduces the C=C double bond. it does not affect any other bond in the molecule.
Hence, only one molecule of H2 is required to reduce one C=C bond present.
A baseball struck by a bat flies away from the batter because
of:
a) Normal force
b) Friction
c) Electrical Force
O d) Applied Force
Answer:
the answer is applied force
How many neutrons are there in a neutral argon atom? Show how you found your answer on your scratch paper.
Suppose we have 100 g of each of the following substances. Which sample contain the greatest number of moles (F.W. = Formula Weight) A. HCI, F.W. = 36.5 B. H_2O, F.W. = 18.0 C. MgCO_3 F.W. = 84.3 D. AlCI_3, F.W. = 133.3 E. NaCl, F.W. = 58.4
Answer:
100 g of water has the highest number of moles
Explanation:
Recall that the number of moles is obtained as given mass/formula weight
For HCl;
number of moles = 100g/36.5g/mol = 2.7 moles
For H2O;
number of moles = 100g/18g/mol = 5.5 moles
For MgCO3
number of moles = 100g/84.3 g/mol = 1.2 moles
For AlCl3
number of moles = 100g/133.3g/mol = 0.75 moles
For NaCl
number of moles = 100g/58.4 g/mol = 1.7 moles
The base that will NOT combine with 2-deoxyribose to form a nucleic acid is _____.
Answer:
Uracil
Explanation:
The base that will NOT combine with 2-deoxyribose to form a nucleic acid is Uracil.
2-deoxyribose is a pentose sugar found in the DNA (Deoxyribonucleic acid). It is devoid of oxygen in its 2' position. The bases found in DNA are Adenine, Guanine, Cytosine and Thymine. Adenine, Guanine, and Cytosine are also found in RNA (Ribonucleic acid). Thymine is not present in RNA, it is only found in DNA. The base found in RNA is Uracil which in turn is not present in DNA. The five carbon sugar present in RNA is ribose which combines with Uracil.
Which best describes the nature of photosynthesis?
It is an energy-attracting process.
It is an energy-building process.
It is an energy-releasing process.
It is an energy-storing process.
Answer:
an energy storing process i think!
Answer:
d
Explanation:
mha
A different element has chemical properties that are similar to the properties of sodium. Which of the following statements about this element is probably true? (1 point) a It is in the same row as sodium on the periodic table. b It is in the same column as sodium on the periodic table. c It has one more proton than sodium. d It has an equal number of protons as sodium.
Answer:I think it's in the same column as a sodium on the periodic table because chemical properties are based on their electron structure and the columns called groups are elements with the same shell structure which increases in mass as you go down the column, therefore the elements which are similar to sodium must be in the same group.
Explanation:
Which one of the following compounds utilizes both ionic and covalent bonding?A) C6H12O6.B) CC32-.C) CO2.D) MgCl2.E) Al2(SO4)3.
Answer:
Al2(SO4)3
Explanation:
Looking at this carefully, we will discover that Al2(SO4)3 is composed of Al^3+ and SO4^2-.
The aluminum and sulphate ions are ionically bonded. However, the oxygen and sulphur in the sulphate ion are covalently bonded.
Hence, Al2(SO4)3 contains both ionic and covalent bond.
The chemical compound which utilizes both ionic and covalent bonding is: E. [tex]Al_2(SO_4)_3[/tex]
An ionic bond refers to a chemical bond that involves a metallic element transferring one or more electrons to a non-metallic element.
On the other hand, a covalent bond can be defined as a chemical bond that typically exists in chemical compounds and involves the sharing of electrons between the atoms of their chemical element.
In this scenario, we can say that the atoms of aluminum and sulfate ion utilizes an ionic bond because the aluminum atom transfers its electrons to the sulfate ion.
However, there exist is a covalent bond between the atoms of oxygen and sulfur to form sulfate ions.
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