Answer:
I think it's true. But I'm not sure
Answer:
True
Explanation:
What type of reaction occurs between an element and a compound?
Answer:
exothermic reaction
Explanation:
because it occurs in the presence of heat
If 33.9g NaCl are mixed into water and the total mass is 578g, what is the CHANGE in freezing if Kb= - 1.82C/M (molal)? Assume NaCl does not dissociate in solution.
Answer:
-1.82 °C
Explanation:
Step 1: Given data
Mass of NaCl (solute): 33.9 gMass of water (solvent): 578 g = 0.578 kgFreezing point depression constant for water (Kb): -1.82 °C/mStep 2: Calculate the molality of the solution
We will use the following expression.
m = mass of solute / molar mass of solute × kg of solvent
m = 33.9 g / 58.44 g/mol × 0.578 kg
m = 1.00 m
Step 3: Calculate the freezing point depression (ΔT)
The freezing point depression is a colligative property that, for a non-dissociated solute, can be calculated using the following expression:
ΔT = Kb × m
ΔT = -1.82 °C/m × 1.00 m
ΔT = -1.82 °C
bond energy is the greatest for?. a: Ch4 b: O2 c: N2 d: Cl2
It's answer is c. N2
The maximum bond energy is of N2 because N2 molecule is formed by 3 covalent bonds and O2 molecule is formed by 2 covalent bonds.
Hope it helps :)
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.
Which compound would you expect to be soluble in the nonpolar solvent carbon disulfide?
Answer:
hexane C6H14
IS YOUR ANSWER
Explanation:
I HOPE IT HELPS MATE
MARK ME BRAINLIEST PLS
I WILL ALWAYS HELP YOU UNDERSTANDING YOUR ASSINGMENTS
HAVE A GREAT DAY
#CAPTAINPOWER :)
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!
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) Calculate the standard reaction entropy for the combustion of methane to carbon dioxide and liquid water at 298 K. b) Calculate the standard reaction entropy for the hydrolysis of liquid water to form oxygen and hydrogen gas. c) Do your results in (a) and (b) agree with the general rule that reaction entropies are positive if there is a net formation of gas in a reaction, and negative if the is a net reduction of gas?
Answer: (a) [tex]\Delta S^{0}[/tex] = - 242.2J/K.mol
(b) [tex]\Delta S^{0}[/tex] = 163.34J/K.mol
(c) Yes
Explanation: Entropy is the measure of randomness or disorder of a system. Standard Entropy has the symbol [tex]S^{0}[/tex].
Mathematically, Entropy is defined as
[tex]\Delta S^{0}=\Sigma S^{0}(products)-\Sigma S^{0}(reagents)[/tex]
Each substance has its own entropy value.
(a) Combustion of Methane:
[tex]CH_{4}+2O_{2}[/tex] ⇒ [tex]CO_{2}+2H_{2}O[/tex]
Using standard entropy table, entropy will be:
[tex]\Sigma S^{0}(products)=214+2(69.91)[/tex] = 353.8
[tex]\Sigma S^{0}=186.264+2(205.138)[/tex] = 596.54
[tex]\Delta S^{0}=[/tex] 353.8 - 596.54
[tex]\Delta S^{0}=[/tex] - 242.2
Standard Entropy for combustion of methane is [tex]\Delta S^{0}=[/tex] - 242.2 J/K.mol.
(b) Hydrolysis of Water:
[tex]H_{2}O_{(l)}[/tex] ⇒ [tex]H_{2}_{(g)}+1/2O_{2}_{(g)}[/tex]
[tex]\Sigma S^{0}(products)=130.684+0.5(205.138)[/tex] = 233.253
[tex]\Sigma S^{0}(reagents)=69.91[/tex]
[tex]\Delta S^{0}=[/tex] 233.253 - 69.91
[tex]\Delta S^{0}=[/tex] +163.34
Standard Entropy for hydrolysis of water is [tex]\Delta S^{0}=[/tex] + 163.34 J/K.mol
(c) Yes, the results prove the general rule: Reactions Entropies are positive for net formation of gas and negative for net reduction of gas. This happens because, as entropy is the measure of disorder, the entropy for gases are greater than for liquids and solids. So, when there is formation of a gas, Entropy increases and when there isn't, entropy decreases.
explain the early theories of the atomic structure
Hi
i hope this helps
Answer:
The Greek atom theory
Explanation:
The concept of the Greek atomos theory is an indivisible particle of matter, goes back to ancient Greece and a man named Democritus held that all matter could be subdivided only until some finite particle was reached.
Which of the following would be most useful in trying to obtain procedural information to replicate an experiment previously published?
Answer: Peer-reviewed journal article is the most useful because the information in them had been carefully scrutinized and aproved by people who are experts in that particular field.
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.
4. Kendrick drags his bat out to play baseball. which statement best describes the science of what he did?
O Kendrick would use less energy if he dragged the bat faster.
Kendrick did not have to work to move the bat because he dragged it.
Kindrick gave the bat potential energy.
Kindrick gave the bat kinetic energy.
Explanation:
Kendrick gave the bat potential Energy
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]
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
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:
What is the concentration of a solution made by diluting 35 mL of 6.0 M HCl to a final volume of 750 mL?
If 2.49g of CuNO3 is dissolved in water to make O.830M solution, what is the volume of the solution in milliliters?
How many moles of NaOH are present in 13.5mL of 0.17 M NaOH?
Answer:
1. 0.28M
2. 24mL
3. 0.002295moles of NaOH.
Explanation:
1. The 6.0M HCl solution is diluted from 35mL to 750mL, that is:
750mL / 35mL = 21.43 times
The 6.0M HCl solution is diluted 21.43 times, the final concentration is:
6.0M / 21.43 = 0.28M
2. First, we need to convert grams of CuNO3 to moles and then, as molarity is moles per liter we can solve for volume of solution in liters and convert it to mililiters:
Moles CuNO3 -Molar mass 124.9g/mol:
2.49g * (1mol / 124.9g) = 0.020 moles of CuNO3
Volume is:
0.020 moles * (1L / 0.830mol) = 0.0240L * (1000mL / 1L) = 24mL
3. In 13.5mL = 0.0135L of 0.17M NaOH the moles are:
0.0135L * (0.17mol / L) = 0.002295moles of NaOH
Consider the equation:
4Al + 3O2 = 2Al2O3
Is this equation balanced? Why or why not?
The equation is balanced. There are 4 aluminium atoms and 6 oxygen atoms on each side.
Help me if you know this pleaseeee
Answer:
help you with what?
Explanation:
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.
Solve for x in the following equation?
v=w/x
Answer:
x = w/v
General Formulas and Concepts:
Pre-Algebra
Equality PropertiesExplanation:
Step 1: Define
v = w/x
Step 2: Solve for x
Multiply x on both sides: xv = wDivide v on both sides: x = w/vmiddle school science help please
Answer:
The answer is 'All of the above'
Explanation:
because the hydrogen ions are represented by the symbol H+, they increase the PH value of a solution if less amount is added but they decrease the PH value of a solution if a larger amount of hydrogen ions are added but still they increase the PH value, and of course, they contribute to a solution by a base.
Answer:
Hydrogen ions are represented by H+.
Explanation:
Hydrogen ions usually decreases the pH value when added to a solution.Hydrogen ions are contributed to a solution by a acid.In the acetylene torch, acetylene gas (C2H2)(C2H2) burns in oxygen to produce carbon dioxide, water, and energy: 2C2H2(g)+5O2(g)⟶Δ4CO2(g)+2H2O(g)2C2H2(g)+5O2(g)⟶Δ4CO2(g)+2H2O(g) You may want to reference (Pages 241 - 243) Section 7.7 while completing this problem. Part A How many moles of O2O2 are needed to react with 1.85 molmol of C2H2C2H2? Express your answer to three significant figures and include the appropriate units. nn(O2O2) = nothingnothing SubmitRequest Answer
Answer:
4.63 mol
Explanation:
Step 1: Write the balanced complete combustion reaction of acetylene
2 C₂H₂(g) + 5 O₂(g) ⟶ 4 CO₂(g) + 2 H₂O(g)
Step 2: Establish the appropriate molar ratio
According to the balanced equation, the molar ratio of C₂H₂ to O₂ is 2:5.
Step 3: Calculate the number of moles of O₂ needed to react with 1.85 moles of C₂H₂
We will use the stoichiometric molar ratio.
1.85 mol C₂H₂ × (5 mol O₂/2 mol C₂H₂) = 4.63 mol O₂
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:
Q 16.1: Select the first step in the Wittig reaction. A : The alkyltriphenylphosphonium halide is deprotonated by a base to make a phosphorus ylide. B : The phosphorus ylide reacts with the aldehyde or ketone to make an oxaphosphetane. C : Triphenylphosphine attacks the alkyl halide to produce an alkyltriphenylphosphonium halide. D : The oxaphosphetane decomposes to form the alkene and triphenylphosphine oxide.
Answer:
The phosphorus ylide reacts with the aldehyde or ketone to make an oxaphosphetane.
Explanation:
The Wittig reaction is a reaction that occurs between a phosphorus ylide and an aldehyde or ketone. The final products are an alkene and triphenyl phosphine oxide.
The first step in the reaction is the attack of the phosphorus ylide on the aldehyde or ketone. This is followed by attack of oxygen on phosphorus to form a [2+2] cycloaddition product (oxaphosphetane) which decomposes to form the alkene and triphenylphosphine oxide.
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. :)
explain 5 the major innovation made from Abacus to the present fifth generation
Answer:
The major innovation made from Abacus to the present fifth generation is explained below in details.
Explanation:
Industrial Age - 1600
John Napier, a Scottish noble and diplomat consecrated much of his holiday time to the learning of mathematics. He was particularly engrossed in devising methods to aid estimates. His most famous offering was the discovery of logarithms. He listed logarithmic measures on a set of 10 board rods and thus was capable to do multiplication and division by equaling up numbers on the poles. These became recognized as Napier’s Bones.
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
Because of gravity, your weight
on the Moon
A. would be the same as it is on Earth
B. would be less than your weight on Earth
C. would be more than your weight on Earth
D. and your mass would be less than it is on Earth
Answer:
the answer is b
Explanation:
brcause the gravutational pull on the moon is lower than on earth...
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 happens to a rock formation that undergoes a repeated and frequent freeze and thaw cycle of water?
Answer:
Water from melting snow or rainfall infiltrates into cracks in rocks. ... As this process of freezing and thawing happens repeatedly, the rock begins to weaken and eventually breaks apart into angular fragments.
Explanation:
Water melting from snow or rainfall which infiltrates into cracks in rocks, this is repeated process of freezing and thawing, the rock begins to weaken and eventually breaks apart into angular fragments.
What are types of rock layers ?A rock can be formed due to the aggregation of mineral constituents in the earth’s crust and it can be classified is based on different factors like Geological classification, Physical classification, Chemical classification.
Geological classification can be either Sedimentary rock formed by the deposition of sediments by the weathering of pre-existing rocks and it can be carried out by various agents like water, wind, gravity, etc.
Igneous rocks formed by the solidification of magma below the earth’s surface which is held together below the earth’s surface and unable to descend, when these magma cools down and solidifies into igneous rocks.
Learn more about rock layer, here:
brainly.com/question/21634781
#SPJ6