Answer:
The mole is important because it allows chemist to work with a subatomic world with macro world units and amount. Atoms molecules and formula units are very small and very difficult to work with usually. However the mole allows a chemist to work with amount large enough to use.
In the International System of Units, the mole is the unit of substance quantity. How many elementary entities of a certain substance are present in an item or sample is determined by the quantity of that material.
Three significance of Mole concept are:
1) Since atoms and molecules are so tiny, we can count them using the mole idea by weighing extremely little quantities of material.
2) It sets a benchmark for figuring out the stoichiometry of reactions.
(3) It explains the characteristics of gases.
The mole is specified as exactly 6.02214076×10²³ elementary entities.
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which rock is the result of changes on the Earth's surface?
igneous rock
sedimentary rock
metamorphic rock
Answer:
metamorphic
Explanation:
when one rock changes another rock the rock that got changed is now metamorphic
when 45mL of 0.25mol/L sulfuric acid is mixed w/ 25mL of 0.58mol/L Calcium hydroxide, the solution has a?
how many moles of methane are in 7.31*10^25 molecules?
121 mol CH₄
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Organic
Writing chemical compoundsWriting organic structuresPrefixesAlkanes, Alkenes, AlkynesAtomic Structure
Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:Step 1: Define
7.31 × 10²⁵ molecules CH₄
Step 2: Identify Conversions
Avogadro's Number
Step 3: Convert
[tex]\displaystyle 7.31 \cdot 10^{25} \ molecules \ CH_4(\frac{1 \ mol \ CH_4}{6.022 \cdot 10^{23} \ molecules \ CH_4} ) = 121.388 \ mol \ CH_4[/tex]
Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
121.388 mol CH₄ ≈ 121 mol CH₄
Why are electromagnetic Waves important society today?
Answer Electromagnetic waves are used to transmit long/short/FM wavelength radio waves, and TV/telephone/wireless signals or energies. They are also responsible for transmitting energy in the form of microwaves, infrared radiation (IR), visible light (VIS), ultraviolet light (UV), X-rays, and gamma rays.
Explanation:
Electromagnetic waves are important in society today because they are used to "transmit long/short/FM wavelength radio waves, and TV/telephone/wireless signals or energies. They are also responsible for transmitting energy in the form of microwaves, infrared radiation (IR), visible light (VIS), ultraviolet light (UV), X-rays, and gamma rays."
4. Pb +FeSO, - PbSO, +Fe
Reaction Type:
Answer:Fe
Explanation:
which are exmaples of chemical change?
•baking cookies
• The statue of liberty's metal tarnishes from copper to green
• cold butter melts into liquid when heated
•salt is dissolved into freshwater
•Food scraps decompose into fertilizer in a compost pile
• frying changes the color and texture of an egg
•ocean water evaporates to water vapor on a hot day
•lighting a match
Answer:
cold butter melted when heated, lighting a match, baking cookies,
Explanation:
What kind of fossil is made when a creature is buried under sediment and as that sediment forms into rock the hard materials like bones of the organism are formed into the rock?
Answer:
Mold fossil
Explanation:
It's called a mold fossil because they are formed when sediments bury an organism and then the sediments are changed into rock; then the organism decays thereby leaving a cavity in the shape of the organism
Question
WHMIS legislation states that Material Safety Data Sheets:
A)are expired if they are more than 3 years old
B) must be available for workers to review
C)are expired if they are more than 5 years old
D )both a and be
E) both b and c
Answer: B) must be available for workers to review
Explanation:
WHMIS is a Canadian program which gives information to the employers about the workers knowledge about hazardous materials that are used in the workplace. It is ensured that the worker labelled the hazardous material at the workplace, material safety data sheet should be created to supplement the label, and worker's education program for learning the safety precautions is also conducted.
The material safety data sheets are created by the employers and their is no expiry date for such data for workers instead they receive a next recommended training date for participating in the training and avail another certification after the completion of first year.
Which of the following is an example of a precipitate?
A: liquid evaporating into gas
B: a solid formed from a frozen liquid
C: a chunky solid formed from two liquids combining
D: a liquid solution that contains two substances
Calculate the new volume if a 13.40 L of a gas at a pressure of 1.51 atm is subject to a new pressure of 65 mmHg.
Answer:
V₂ = 238.05 L
Explanation:
Given data:
Final volume = ?
Initial volume = 13.40 L
Initial pressure = 1.51 atm
Final pressure = 65 mmHg ( 65/760 = 0.085 atm)
Solution:
The given problem will be solved through the Boyle's law,
"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"
Mathematical expression:
P₁V₁ = P₂V₂
P₁ = Initial pressure
V₁ = initial volume
P₂ = final pressure
V₂ = final volume
Now we will put the values in formula,
P₁V₁ = P₂V₂
1.51 atm × 13.40 L = 0.085 atm × V₂
V₂ = 1.51 atm × 13.40 L / 0.085 atm
V₂ = 238.05 L
Which of these substances has a definite volume but not a definite
shape?
A. paper
B. grass
C. juice
D. water vapor
Dinitrogen pentoxide is used in the preparation of explosives. If 7.93 mol of
dinitrogen pentoxide undergoes simple decomposition, what volume of Oz(9) is
produced at 48.0 °C and 125 kPa?
The volume of O₂ produced: 84.6 L
Further explanationGiven
7.93 mol of dinitrogen pentoxide
T = 48 + 273 = 321 K
P = 125 kPa = 1,23365 atm
Required
Volume of O₂
Solution
Decomposition reaction of dinitrogen pentoxide
2N₂O₅(g)→4NO₂(g)+O₂ (g)
From the equation, mol ratio N₂O₅ : O₂ = 2 : 1, so mol O₂ :
= 0.5 x mol N₂O₅
= 0.5 x 7.93
= 3.965 moles
The volume of O₂ :
[tex]\tt V=\dfrac{nRT}{P}\\\\V=\dfrac{3.965\times 0.082\times 321}{1.23365}\\\\V=84.6~L[/tex]
You have a stock solution of HNO3 with a concentration of 4.5 x 10^-4 M. However, you need 275 ml of a 2.50 x 10^-5 M solution. How much of the stock solution will you need?
Answer:
15.28 mL
Explanation:
From the question given above, the following data were obtained:
Molarity of stock solution (M₁) = 4.5x10¯⁴ M
Volume of diluted solution (V₂) = 275 mL
Molarity of diluted solution (M₂) = 2.5×10¯⁵ M
Volume of stock solution (V₁) needed =.?
The volume of the stock solution needed can be obtained by using the dilution formula as illustrated below:
M₁V₁ = M₂V₂
4.5x10¯⁴ × V₁ = 2.5×10¯⁵ × 275
4.5x10¯⁴ × V₁ = 0.006875
Divide both side by 4.5x10¯⁴
V₁ = 0.006875 / 4.5x10¯⁴
V₁ = 15.28 mL
Therefore, the volume of the stock solution needed is 15.28 mL
Explain in a short sentence how you can tell a reaction is a decomposition reaction.
Answer: A decomposition reaction occurs when one reactant breaks down into two or more products.
Mark me as brainilist pls
What is the conversion for 2.0 m x 5.0 m =
What is the molecular formula of a compound that is 51.02 % carbon, 13.80 % hydrogen, and 35.18 %
oxygen? The molecular mass is 88.0 g/mol.
Answer:
Molecular formula = C₄H₁₂O₂
Explanation:
Given data:
Percentage of hydrogen = 13.80%
Percentage of carbon = 51.02%
Percentage of oxygen = 35.18%
Molecular formula = ?
Solution:
Number of gram atoms of H = 13.80 / 1.01 = 13.6
Number of gram atoms of O = 35.18 / 16 = 2.2
Number of gram atoms of C = 51.02 / 12 = 4.25
Atomic ratio:
C : H : O
4.25/2.2 : 13.6/2.2 : 2.2/2.2
2 : 6 : 1
C : H : O = 2 : 6 : 1
Empirical formula is C₂H₆O.
Molecular formula:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
Empirical formula mass = C₂H₆O = 46 g/mol
n = 88 / 46
n = 2
Molecular formula = n (empirical formula)
Molecular formula = 2 (C₂H₆O)
Molecular formula = C₄H₁₂O₂
A 10.0-liter flask contains 1.013 grams of oxygen and .572 grams of carbon dioxide at 180C. What are the partial pressures of oxygen and carbon dioxide? What is the total pressure? What is the mole fraction of oxygen in the mixture?
P tot = 0.1065 atm
The mole fraction of oxygen in the mixture : 0.709
Further explanationGiven
10 L flask
1.013 g O₂
572 g CO₂
T = 18 °C = 291 K
Required
P O₂ and P CO₂
Solution
Dalton Law's of partila pressure
P tot = P₁ + P₂ + ..Pₙ
From ideal gas Law :
[tex]\tt P_{O_2}=\dfrac{\dfrac{1.013}{32}\times 0.082\times 291 }{10}\\\\P_{O_2}=0.0755~atm[/tex]
[tex]\tt P_{CO_2}=\dfrac{\dfrac{0.572}{44}\times 0.082\times 291}{10}\\\\P_{CO_2}=0.031~atm[/tex]
P tot = P O₂ + P CO₂
P tot = 0.0755 + 0.031
P tot = 0.1065 atm
The mole fraction of O₂ :
[tex]\tt P_{O_2}=X_{O_2}\times P_{tot}\\\\X_{O_2}=\dfrac{P_{O_2}}{P_{tot}}\\\\X_{O_2}=\dfrac{0.0755~atm}{0.1065~atm}\\\\X_{O_2}=0.709[/tex]
Which of the following correctly lists the levels of organization from most complex to least complex? *
Community, Organism, Population, Ecosystem
Ecosystem, Community, Population, Organism
Population, Community, Ecosystem, Organism
Organism, Population, Community, Ecosystem
Answer:
The last option.
Explanation:
You can immediately eliminate the other options as an organism is clearly the least complex. Only one option begins w/ 'organism'.
Answer:
Its def A, if this helped subscribe to amiredagoat Yt
Explanation:
What is a cation and where can you find it on the periodic table?
What is an anion and where can you find it on the periodic table?
Answer:
A cation is an ion with fewer electrons than protons. Therefore, it has a positive charge. The electric charge on a proton is equal in amount to the charge on an electron. Anions are atoms or radicals (groups of atoms), that have gained electrons. Since they now have more electrons than protons, anions have a negative charge. Halogens always form anions, alkali metals and alkaline earth metals always form cations. Most other metals form cations (e.g. iron, silver, nickel), whilst most other nonmetals typically form anions (e.g. oxygen, carbon, sulfur).
Explanation:
An anion and cation cannot be specifically found on the periodic table.
The chemical elements are shown in tabular form on the periodic table, sometimes referred to as the periodic table of the elements. It is frequently used in physics, chemistry, and other sciences and is frequently regarded as a symbol of chemistry.
What is an anion?An ion with fewer electrons than protons is known as a cation. It is hence positively charged. Protons and electrons both have the same amount of electric charge. Atoms or radicals (groups of atoms) that have gained electrons are known as anions. Anions now have a negative charge because they have more electrons than protons.
Alkali metals and alkaline earth metals always produce cations, while halogens always produce anions. Iron, silver, and nickel are among the most common non-metals that create cations, whereas the majority of other metals do the same (e.g. oxygen, carbon, sulphur).
The periodic table does not clearly list an anion or cation.
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Where does the waste material in the body come from
and why does the body need to get rid of these waste
materials?
Answer:
The cells of the body produce waste materials. The body needs to get rid of these waste materials because they can make us sick. Getting rid of this waste keeps us healthy.
Explanation:
____________________________________________________________
The Answer I Put On Mine:____________________________________________________________
The cells inside of your and my body alike produce these waste materials. We need to get rid of them because if we don't, we could get sick! Or possibly cause something worse...
____________________________________________________________
Why?____________________________________________________________
Well, the answer kind-of explains all I would want to say! Feel free to copy and paste this on your assignment, but do NOT use the sample answer like the other person who answered this did. (The sample answer you should NOT use: "The cells of the body produce waste materials. The body needs to get rid of these waste materials because they can make us sick. Getting rid of this waste keeps us healthy.") It could make your teachers or parents suspicious of your work! Anyways, have a good day! ❥
What is the name of the compound NS2
Answer:
I believe what your looking for is Nitrogen disulfide
Explanation:
Hope this helps (:
define the following terms
A) chemical family
B) period
C) metalloid
Answer:
Chemical Family means a group of elements in the Periodic Table or, more commonly, compounds that share certain physical and chemical characteristics and have a common name.
A period in the periodic table is a row of chemical elements.
metalloid is an element (e.g. arsenic, antimony, or tin) whose properties are intermediate between those of metals and solid nonmetals or semiconductors.
Give two limitations of law of Constant Composition
Answer:
1.The law does not hold true if the different isotopes of the element are involved in making chemical compound.
2.The law is not applicable when elements combine in the same ratio but different compounds are formed.
How many grams of potassium phosphate (K3PO4) will be formed if you react 20.16 grams of potassium hydroxide (KOH) with excess phosphoric acid?
3 KOH + H3PO4 → K3PO4 + 3 H2O
_ grams of K3PO4 (round to 3 sig figs)
a) 234
b) 25.4
c) 64.5
d) 58.7
25.4g of potassium phosphate (K3PO4) are formed.
What is potassium phosphate?Potassium phosphate is an inorganic salts of potassium and phosphate.
How to convert mole to grams?Calculate the number of moles mentioned in the questionFind the molar mass of the substance.Multiply both the values.3 KOH + H3PO4 → K3PO4 + 3 H2O
Step 1: Convert from grams to moles using the molar mass.
Step 2: Use the molar ratio to determine moles of other substance.
Step 3: Convert from mole to grams using the molar mass.
Convert grams to moles using the molar mass
25.4g KOH (1 mol KOH/56.098g KOH)
= 0.3593mol KOH
Mass of H3PO4 produced
0.3593 mol KOH ( 1 mol H3PO4/3 mol KOH)
= 0.1197 mol H3PO4
converting mole to grams
0.1197 mol H3PO4 (98g H3PO4/1 mol H3PO4)
= 11.730g H3PO4
Mass of K3PO4 produced
0.3593 mol KOH (1 mol K3PO4/3 mol KOH)
= 0.1197 mol K3PO4
converting mole to grams
0.1197 mol K3PO4 (212.267g K3PO4/1 MOL K3PO4)
= 25.408g K3PO4
Hence, option b is the correct answer.
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Is it technically correct to call ionic compounds molecules?
Answer:
uh yeah I think so technically
Answer:
no
Explanation:
Which statements about freshwater sources are true? Check all that apply.
O Only about 3 percent of Earth's water ís fresh water.
O Most of the fresh water on Earth is groundwater.
O About 75 percent of the fresh water on Earth is frozen in ice sheets.
O The largest source of usable fresh water is groundwater.
O More fresh water is in the atmosphere than in rivers and lakes.
Answer:
Explanation:
1 is true
2 is false
3 is true
4 is true
5 is false
That is what I got from researching.
Only about 3% of the water in the Earth is fresh water and about 75 % of the fresh water on Earth is frozen in ice sheets.
• The most vital element present on the Earth is water. All the living beings are dependent on it.
• Water is present in the majority of the Earth, however, of this only 3% of the water is freshwater, the rest is saline and undrinkable.
• Of this 3%, the 75 percent of the freshwater is present in the form of ice and glaciers in the polar region.
• The remaining 24 percent is the groundwater and the rest 1 percent includes the waters of rivers, lakes, and ponds.
• The prime source of usable freshwater is present in the trapped form in the ice and glaciers.
Thus, the correct statements are 1st and 3rd.
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A student states, "When the alcohol sample was at a temperature of 500 K, all the particles were moving faster than any of the particles were moving at 400 K." Do you agree or disagree with this student’s statement? Justify your answer
Answer: i rlly dont know srry
Explanation:
1. What do you observe when you poor a hot into the glass
containing intant coffee?
Answer:
The water in glass turns dark brown.
This is due to diffusion where the coffee molecules move from the region of their high concentration to a region of their lower concentration in water.
Answer:
The instant coffee acts as a solute when hot water (the solvent) is poured. The instant coffee quickly dissolves and makes a solution.
Explanation:
R-0-R.
What functional group is it
Identify the chemical reaction Below:
Ca(OH)2 + HCI CaCl2 + H20
Answer:
Neutralizaion reaction!
Explanation:
Calciumhydroxide under Hydrochloric acid gives Calciumchloride with the formation of water.