Answer:
6.64 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{4 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 6.644518...[/tex]
We have the final answer as
6.64 molesHope this helps you
What are the rules for writing
names/formulas for ionic
compounds? Give examples
where you need to produce
the formula from the name
AND the name from the
formula. Make sure to
include examples of
transition metals and
polyatomic ions.
what's the formula for na and f , ca and br , mg and O
Answer:
NaF, CaBr2, MgO
Explanation:
Hi! For this problem, you are going to want to look at the charges of the elements in order to write their formulas.
NaF: Na has a charge of +1 and F has a charge of -1. This means that they have a 1:1 ratio and the formula is written as such - NaF.
CaBr2: Ca has a charge of +2 and Br has a charge of -1. For this problem you want to make sure that their formal charge (the charge of the entire molecule) equals 0. This means that the negative charges need to equal the positive charges. Looking at this, you are going to need to Br ions with a charge of -1 to equal one Ca ion with a charge of +2 - CaBr2.
MgO: Mg has a charge of +2 and O has a charge of -2. This means that they have a 2:2 ratio which simplifies to a 1:1 ratio and the formula is written as such - MgO.
Hope this helps!
. A student adds 50 mL of Lead (II) Nitrate solution to 50 mL of potassium iodide. Each
solution is colorless, but when these two liquids are mixed, a yellow precipitate is
observed. What has most likely happened in the experiment?
Answer:
after the reaction between Lead (II) Nitrate solution and potassium iodide occur Lead(II) iodide was formed and it's yellow color.
Explanation:
Pb(NO3)2 + KI = KNO3 + PbI2
When the volume of a gas is
changed from 3.6 L to 15.5 L, the
temperature will change from
°C to 87°C.
Assume that the number of moles and the
pressure remain constant.
Be sure to notice that temperatures are
given in °C!
Answer:
-189.55°C
Explanation:
Given data:
Initial volume of gas = 3.6 L
Final volume of gas = 15.5 L
Initial temperature = ?
Final temperature = 87°C (87+273 = 360 K)
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
V₁ = Initial volume
T₁ = Initial temperature
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
T₁ = V₁T₂ /V₂
T₁ = 3.6 L × 360 K / 15.5 L
T₁ = 1296 L.K / 15.5 L
T₁ = 83.6 K
Kelvin to °C:
83.6 K - 273.15 = -189.55°C
What would have a higher boiling point water or hydrocarbon ( from penny liquid stacking)
Answer:
Im pretty sure its hydrocarbon
Explanation:
Name one way that the scientific community has honored Mendeleev’s contribution to science.
Answer:
Mendeleev's greatest contribution to science is certainly the Periodic Table of Elements, which says the properties of basic elements repeat periodically when they are arranged by their atomic number. He made the discovery in 1869 during his work on the award-winning textbook on chemistry basics.
Inventions: Periodic table, Pyrocollodion
Explanation:
*Hope this helps*
Answer:
Mendeleev's greatest contribution to science is certainly the Periodic Table of Elements, which says the properties of basic elements repeat periodically when they are arranged by their atomic number. He made the discovery in 1869 during his work on the award-winning textbook on chemistry basics.
Inventions: Periodic table, Pyrocollodion
Explanation:
Show the calculation of the molality of a solution made by dissolving 15.9 grams of Ca3(PO4)2 in 400 grams of water.
The molality of a solution : 0.128 m
Further explanationGiven
15.9 g of Ca3(PO4)2 in 400 grams of water.
Required
The molality
Solution
molality = mol solute / kg solvent
solute= Ca3(PO4)2(MW=Molecular Weight: 310.2 g/mol)
mol solute :
[tex]\tt \dfrac{15.9}{310.2}=0.0512[/tex]
The molality :
[tex]\tt \dfrac{0.0512}{0.4~kg}=0.128~m[/tex]
Help me if you know this pleaseeee
Answer:
help you with what?
Explanation:
please help me i will give brain list
Answer:
a. pentane = C5H12
b. Heptane = C7H16
c. Hexyne = C6H10
d. Octene = C8H16
e. Nonane = C9H20
Hope it helps.
1-pentene
Molecular Formula C5H10
Condensed Structural FormulaCH2=CH(CH2)2CH3
Melting Point (°C)–138
Boiling Point (°C)30
2- heptane is the straight-chain alkane with the chemical formula H3C(CH2)5CH3 or C7H16, and is one of the main components of gasoline (petrol).
HELP ASAP DUE IN 5 MINUTES WILL GIVE BRAINLIEST
Energy is conserved within a system, meaning that forms of energy are either transferred or transformed as they interact with objects. Which of the statements below correctly describe how energy is transferred or transformed in daily life?
Group of answer choices
Kinetic energy transforms into thermal energy when a heating pad is turned on.
Electrical energy is transferred into light energy so that a flashlight generates light when it’s turned on.
Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street.
Nuclear energy is transferred to electrical energy to provide electricity for our homes.
Answer:
i do believe it is C. Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street. but if i am wrong plz don't come at me but i believe that is right
Explanation:
Answer:
i do believe it is C. Chemical energy in food is transformed into mechanical energy as our body rides a bicycle down the street. but if i am wrong plz don't come at me but i believe that is right
Explanation:
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:
(
)BaO2 + (
)H2SO4 → (
)H2O2 + (
)BaSO4
Answer:
1
1
1
1
Explanation:
the equation is balancing
Question 1 / 1
Which of the following is a covalent bond?
A. CO2
B. NaCl
C. Fe2O,
Answer:
Chemistry deals with matter, and there is a tremendous variety of matter in the universe. The behavior of matter depends on the type of elements that are present and on the structure of those elements—how they are connected to make a molecule. In this exercise, you will evaluate some representative models to develop the rules used to classify a compound, to predict the formula of a compound, and to name the compound. This exercise is just the beginning of the work needed to be done to master the rules of writing formulas and nomenclature. Your textbook has tables of the names and formulas of common cations and anions, and discusses the rules of nomenclature in detail. You will need to spend some time with this material, as the formal rules of nomenclature may not be presented in lecture, although they will certainly be used in discussions of Lewis structures and reaction chemistry.
Explanation:
In a covalent compound, valence electrons are shared between the two atoms in the bond. These can be evenly shared (covalent bond) or unevenly shared (polar covalent bond). In an ionic bond, electrons are localized to one of the atoms (giving it an overall negative charge), while the other atom has an overall positive charge. The difference in electronegativity between the two atoms in the bond can help predict whether the bond is likely to be ionic, covalent, or polar covalent, as can the type of atoms involved (metals or non-metals). A bond with two identical atoms is always pure covalent, while a covalent bond with two different atoms is likely to be polar covalent.
A sample is in the second half-life. What percent of the sample is stable at this point?
A. 12.5%
B. 25%
C. 50%
D. 75%
Answer:
75%
Explanation:
on edg :)
Two models of the same compound are shown.
On the left labeled Model A 2 large overlapping black spheres with 3 small blue spheres overlapping the rear black sphere and 2 medium red spheres overlapping the front black sphere. One of the red spheres has a small blue sphere overlapping it. On the right labeled Model B 2 C's connected by a black line. The C on the left has 3 H's attached by 1 black line each and the C on the right has 2 Os attached to it. The top O is attached by 2 black lines and the bottom O by 1 black line. The bottom O also has an H attached to it by 1 black line.
In what way is Model A better than Model B?
Model A shows the types of elements in the compound, but Model B does not.
Model A shows the total number of atoms in the molecule, but Model B does not.
Model A shows the three-dimensional shape of the molecule, but Model B does not.
Model A shows the number of atoms of each element in the molecule, but Model B does not.
Answer: C. Model A shows the three-dimensional shape of the molecule, but Model B does not.
Explanation:
i took the test and it makes the most sence for the modeles.
Elisa feels tired because she has a condition that affects whether the right molecules are getting to her cells. If her body were functioning correctly, this is what would happen with oxygen:
Answer:
It would be working properly and providing her energy for her daily activities.
Explanation:
Hello!
In this case, since her oxygen is actually working properly, it is going to be travelling throughout her entire body (via blood) and therefore carbon dioxide would be released as the exhalation product due to cellular respiration carried out in the alveoli which provides energy for her daily activities.
However, the intrusion of different molecules to oxygen into her cells may affect the rate at which cellular respiration is carried out and therefore she may feel tired because such process provides energy to the body.
Best regards!
which force does the truck use to move the car with it A.push B.pull C.gravity D.Friction
it is push i think to move the car
Answer:
Either A. Push or B.Pull because the truck is either pushing or pulling the car to move it. So it depends on if it's pushing or pulling the car.
Explanation:
Suppose you wish to determine the order of the reaction. You initially measure a rate, r0, given some arbitrary concentration of reactants. You then proceed to double the amount of A in the reaction (keeping B the same) and find that the rate is now 2r0. In a reciprocal experiment, you double the amount of B (A same as initial) in the reaction and measure a rate of 8r0. What is the order of this reaction
Answer:
See explanation
Explanation:
Now taking A, we can see that if we double the amount of A while keeping the amount of B constant, the rate of reaction doubles, hence we can write;
2^n = 2^1
hence n =1
For B, when the amount of B is doubled while keeping the amount of A constant, the rate of reaction increases eight times. Hence we can write;
2^n = 8
2^n = 2^3
n=3
Hence this reaction has an overall order of 1 + 3 = 4
So we can write;
rate =k[A] [B]^3
Create an atom diagram using the Bohr model. Directions Choose three elements from the following list. Use a periodic table to determine the number of protons, neutrons, and electrons. Draw a diagram of each element you have selected. Use a separate piece of paper for each element. Be sure your drawing is neat, legible, and accurate. Use this data table to record information about each element. Element #1 Element #2 Element #3 Element #4
Answer:
Explanation:
proposed an early model of the atom as a central nucleus containing protons and neutrons being orbited by electrons in shells. As previously discussed, there is a connection between the number of protons in an element, the atomic number that distinguishes one element from another, and the number of electrons it has. In all electrically-neutral atoms, the number of electrons is the same as the number of protons. Each element, when electrically neutral, has a number of electrons equal to its atomic number.
Answer:
You can check diagram with number of proton neutron and electrons
Explanation:
Rosie balanced the equation below with the lowest coefficients, however she made a mistake.
2 AgCl + 2 Mg(NO3)2 --> 1 AgNO3 + 2 MgCl2
What was her error and what should the correct answer be?
Answer:
2 AgCl + Mg(NO3)2 --> 2AgNO3 + MgCl2
Explanation:
This is balanced equation
What ratio of concentration of ammonia and ammonium chloride should be mixed to
prepare a buffer solution of pOH 5? (Kb for NH3 =1.8 x 10-4)
The ratio of concentration of ammonia and ammonium chloride : 0.05
Further explanationGiven
pOH=5
Kb for NH3 =1.8 x 10-4
Required
The ratio of concentration of ammonia (NH₃) and ammonium chloride(NH₄Cl)
Solution
Solutions containing ammonia and its salt: ammonium chloride are called alkaline buffers
Can be formulated : ( for the same of the volume, mol=concentration)
[tex]\tt \displaystyle [OH-]=Kb\times\frac{weak\:base\:mole}{salt\:mole\times valence}[/tex]
pOH=-log [OH⁻]
pOH=5⇒[OH⁻]=10⁻⁵
Valence for NH₄Cl = 1, so the concentration ratio :
[tex]\tt 10^{-5}=1.8\times 10^{-4}\times \dfrac{[~NH_3]}{[NH_4Cl]}\\\\0.05=\dfrac{[~NH_3]}{[NH_4Cl]}[/tex]
Which chemical equation below is not balanced?
- 3 MgSO4 + 2 Nag PO4 → Mgs (PO4),+3 Na, S04
- 2 NaOH + HNO, → NaNO, + 2 H,0
- CH12 O6 4 6O2 → 6 CO, + 6 H,0
- HBr AGNO, → HNO, + AgBr
pic if needed ;)
Answer:
B
Explanation:
The second one is not balanced correctly.
2 NaOH + 2HNO3 → 2NaNO3 + 2 H20
I didn't notice this before but it can be balanced without the twos.
NaOH + HNO3 → NaNO3 + H20
It was still wrong. It needed to have the twos removed, not 2 more added. Adding two more isn't wrong, but it should be balanced without 2s if at all possible.
The table shows four reactions.
Reactions
Reaction Equation
C₃ H8+ 50₂ 3C02 + 4H20
2Ca + O2- 2CaO
AgNO3 + NaCl
AGCI + NaNO3
CH3COOH + 202 - 2CO2 + 2H20
4
Which of the above reactions is an example of combustion of an Inorganic substance? (5 points)
Answer: 2
Explanation:
A combustion reaction must include O2 as a reactant.
An inorganic substance almost never includes carbon.
So, by process of elimination:
1. Carbon is a reactant = probably not
2. Has O2, no carbon = yes
3. O2 is not a reactant = no
4. Carbon is a reactant = probably not
An example of the combustion of an inorganic substance is:
2 Ca + O₂ ⇒ 2 CaO
We have 4 reactions and we want to determine which is an example of combustion of an inorganic substance.
What is combustion?A combustion reaction is a reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat.
What is the difference between organic and inorganic substances?Organic substances always contain carbon while most inorganic substances do not contain carbon.
Let's consider the following reactions.
C₃H₈ + 5 O₂ ⇒ 3 CO₂ + 4 H₂OThis is a combustion reaction but C₃H₈ is an organic substance.
2 Ca + O₂ ⇒ 2 CaO
This is an example of the combustion of an inorganic substance.
AgNO₃ + NaCl ⇒ AgCI + NaNO₃
This is not a combustion reaction.
CH₃COOH + 2 O₂ ⇒ 2 CO₂ + 2 H₂O
This is a combustion reaction but CH₃COOH is an organic substance.
An example of the combustion of an inorganic substance is:
2 Ca + O₂ ⇒ 2 CaO
Learn more about combustion here: https://brainly.com/question/4155165
which event would most likely lead to a thunderstorm g i v i n g b r a i n l e s i t
Answer:
A
Explanation:
I took a test like this and my teacher said this was right so ye. hopefully I remembered correctly if its wrong im sorry ;C
Answer: A
Explanation: A thunderstorm forms when warm, moist air rises into cold air. Hope this helps. :)
In a molecule of calcium sulfide, calcium has two valence electron bonds, and a sulfur atom has six valence electrons. How many lone pairs of electrons are present in the Lewis structure of calcium sulfide?
A. one
B. two
C. three
D. four
E. none
Also, state why.
Answer:
E
because it forms the ionic bond but not covalent.
fill in the blank please
amino acids as _____ are to words
Answer:
Sentences are where there is a beginning and an end of a section of a paragraph. Letters are individual parts of sentences.
The answer that would make the MOST sense would be SENTENCES
PLEASE HELP WILL GIVE BRAINLIEST
Answer:
Coefficients represents no of moles while subscripts represent no of atoms.
Answer:
Coefficients came before formula . Example = 4CO means there are 4 molecules of carbonmonooxide.
Subscripts came after and below the formula . Example = Oxygen gas in which 2 is a subscript which means there are 2 atoms of Oxygen in 1 molecule of Oxygen i.e. oxygen gas
What else is produced when sodium carbonate decomposes?
Na2Co3 - Na2O+
Answer:When a single compound breaks down into two or more compounds or elements in a chemical reaction then it is known as decomposition reaction.
The chemical symbol for sodium carbonate is .
The decomposition of sodium carbonate is:
The decomposition of sodium bicarbonate, will result in the formation of sodium oxide, and carbon dioxide, .
Hence, carbon dioxide, will produce with sodium oxide, on decomposition of .
Explanation:Na2CO3 Na2O +CO2 CO2 is the answer
how can use a BIPHASIC LIQUIDS
Answer:
BIPHASIC LIQUIDS are used ear cleaning, to softening the wax so that mild infections can be treated.
Explanation:
BIPHASIC LIQUIDS are liquids that contain two immiscible phases, one is suspension and the other is emulsion. In suspension, the finely solid are dispersed in a liquid or semi solidwhich is use for medicament
The emulsion consist of immiscible liquids, one is dispersed in globules.
They are used ear cleaning, to softening the wax so that mild infections can be treated.
Please help....thank you
Answer:
a. volcanic changes create new land
Which electron dot diagram represents H2?
Answer:
H:H
Explanation: