Answer:
Sulfur hexafluoride
Explanation:
It is heavier than air that we breathe so it has an opposite effect.
Hope this helps. Pls give brainliest. Also pls sub to kgirl633 on yt!
Which statement is true?
A. In an exothermic reaction, the energy of the products is the same as the energy of the reactants.
B. In an endothermic reaction, the energy of the products is the same as the energy of the reactants.
C. In an endothermic reaction, the energy of the products is greater than the energy of the reactants.
D. In an exothermic reaction, the energy of the products is greater than the energy of the reactants.
Exothermic reaction is where there is release of energy during a reaction
The enthalpy of exothermic reaction is negative
The relation between energy of products, reactants and enthalpy of reaction is
Enthalpy of reaction = sum of enthalpy of formation of products - sum of enthalpy of formation of reactants .
As enthalpy of reaction is negative, it means the enthalpy of products is less than the enthalpy of reactants so answer is :
In an exothermic reaction the energy of the product is less than the energy of the reactants.
C.
An endothermic reaction is a reaction that absorbs heat from the surroundings. That means that the energy of the system must increase. Therefore, the answer must be C as the products should have higher energy than the reactants.
Each orbital can contain no more than 2 electrons. This is:
O A. Conservation of energy
OB. The Pauli exclusion principle
C. None of these
D. Hund's rule
Answer: B. The Pauli exclusion principle.
Explanation: Founders Educere answer ;)
Define an ideal gas and explain under which conditions you may reasonably approximate a real gas as an ideal gas. Also mention conditions under which it would be inappropriate to approximate a real gas as an ideal gas. (you may need to use a search engineto help you out here)
Answer:
High temperature and low pressure
Explanation:
According to the kinetic molecular theory, gases are composed of small particles called molecules which are in constant motion.
At high temperature and low pressure, gas molecules possess high kinetic energy and move at high velocities hence intermolecular interaction is almost none existent and real gases approach the behavior of ideal gases.
What is the mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water?
The mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water is 29.7%.
What is mass percent ?Mass percent is a means to describe a component in a specific combination or to convey a concentration. The mass percentage used to describe the solution composition indicates the mass of solute contained in a given mass of solution.
To determine the mass percent of an element in a compound, we divide the mass of the element in one mole of the compound by the compound's molar mass and multiply the result by 100.
Given:
Number of moles = 0.64 moles
Moles of sodium fluoride = Given mass/molar mass
0.64 moles = Mass / 42
Mass = 26.88gram
Mass % = Mass of solute/ mass of solution × 100
= 26.88/90.48 × 100
= 29.7 %
Thus, 29.7 % is the mass percent of a sodium fluoride solution prepared by dissolving 0.64 moles of sodium fluoride into 63.5 grams of water
To learn more about the mass percent, follow the link;
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Trong các yếu tố sau đây: nồng độ, nhiệt độ, áp suất, diện tích tiếp xúc, chất xúc tác, có bao nhiêu yếu tố có thể ảnh hưởng tới tốc độ phản ứng?
Answer:
solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased
Explanation:
solubility of salt at 10 degree Celsius is 20 how does it what does it means what happens if the temperature of saturated solution is increased
Freezing point depression is:
A. When a substance freezes and then quickly drops in temperature.
B. When a substance drops in temperature until it freezes, then quickly rises in temperature but stays frozen.
C. When a substance does not need to be as cold as normal in order to freeze.
D. When a substance must be colder than normal in order to freeze.
Freezing point depression is when a substance must be colder than normal in order to freeze.
Freezing point is that temperature where a liquid substance becomes a solid i.e. freezes. Freezing point depression is the process whereby the temperature at which a substance freezes is lowered.Freezing point depression often occurs when a solute is added to a solvent. This reduces its freezing point. Since temperature is reduced, in other words, this means that the substance must become colder than normal for it to start freezing.
Hence, freezing point depression is when a substance must be colder than normal in order to freeze.
Learn more at: https://brainly.com/question/2785367
D. When a substance must be colder than normal in order to freeze.
Explanation:
hey love, I just took the quiz on this for founder's education. I hope this helped.
Where does reduction occur in an electrochemical cell?
Answer:
The cathode is the electrode where reduction takes place.
so
reduction occur in Cathode in an electrochemical cell.
Answer: Cathode
Explanation:
.
11. A mixture of magnesium powder and lead (II) Oxide will react vigorously when heated but no reaction occurs when a mixture of magnesium oxide and lead powder are heated, a) Explain the observation. b Which of the two substances, magnesium or lead(IT) Oxide is; i) Oxidized in the reaction? ii) Oxidizing agent? C Which is the most reactive metal Please helpA
Answer:
17
Explanation:
i need points
3. What would be the freezing point for a 5.7 molal aqueous sucrose (C12H22O) solution? The freezing
point depression constant for water = 1.86°C/m. Show your work.
Answer:
- 10.6° C
Explanation:
Given that,
In the aqueous sucrose solution,
Molality of the solution (m) = 5.7
Freezing point constant (K) = 1.86
To find,
The freezing point of the solution = ?
Method:
To find its freezing point, we will first find out if the solute demonstrates an electrolyte or not.
In case it is not, the van't Hoff factor i.e. ration of particles' concentration denoted by (i) would be taken as 1. So,
ΔT(change in temperature) = i * m * K (putting the given values)
= 1 * 5.7 * 1.86
= 10.6° C
Thus, the freezing point equals to 0 - 10.6° C = -10.6° C.
I need help getting this done
Answer:
I put the right structures in the pictures for you
C4H9OH have several isomers. Draw structure and IUPAC names of its three isomers.
Answer:
.
Explanation:
Is the following change an oxidation or reduction?
manganese (IV) oxide to manganese (III) oxide.
Answer:
12113
Explanation:
step by step:no
How many grams of solute is there in 250 mL of a 0.10M CaCl2 solution ?
Answer:
2.775 g
Explanation:
Given that;
Number of moles = concentration × volume
Concentration = 0.10M
Volume =250 mL
Number of moles = 250/1000 × 0.10
Number of moles = 0.025 moles
Also;
Number of moles = mass/molar mass
Molar mass of CaCl2= 111 g/mol
Mass = Number of moles × molar mass
Mass = 0.025 moles × 111 g/mol
Mass= 2.775 g
Which element will form In ion whose lonic radius is larger than its atomic radius?
(1) K
(2) F
(3) LI
(4) Mg
Answer:
Letter b so F
Explanation:
I hope this help
Explanation:
All five ions have an equal number of electrons and therefore share the same electron configuration. For example, a neutral calcium atom (Z=20) has 20 electrons; it loses two of them to form a Ca2+ cation, which would thus contain 20−2=18 electrons. Similarly, a phosphorus atom (Z=15) gains three electrons to form a P3− anion that contains 15+3=18 electrons.
Positively-charged protons in the nuclei attract the negatively-charged electron cloud. Each proton carries a +1 charge; the more protons an atom or ion contains the stronger the attraction it poses on its electron cloud. A nucleus of strong positive charge pulls its electron cloud towards itself tightly such that the latter would have a small radius.
The periodic table is arranged in the order of increasing proton number. Phosphorus comes the first among the five species and contains the least number of protons. Its ion would be the largest among the five. Calcium comes the last and forms the smallest ion.
Number of protons per nucleus P<S<Cl<K<CaStrength of Electrostatic attraction on the electron cloud P<S<Cl<K<CaIonic radius P3−>S2−>Cl−>K+>Ca2+
Unknown # 29
Flame Test Color: Green
Addition of HCl(aq): Bubbles
Addition of HCl(aq) and BaCl2(aq): NR (No Reaction)
Addition of HNO3(aq) and AgNO3(aq): White precipitate
What is the unknown ionic compound molecular formula?
Answer:
I think it's a sulphate ion, because when you add hydrochloric acid to it it produces bubbles and when you add barium chloride it then produces a white precipitate.its formula is SO4
I hope this helps
A 240g hydrated sodium sulphide contains 162g of water of crystallisation. What is the correct molecular formula for this compound?
What is the answer and working
Answer:
Explanation:
First of all, 1 mol of Sodium Sulphide has molecular mass of
S = 32
Na2 = 2*23 = 46
The formula of NaS is actually Na2S. It's molecular mass = 78
How many grams of Na2S are present
Grams present = 240 - 162 = 78 which is exactly 1 mol.
The remainder is water.
The molecular mass of water = 2 + 16 = 18
162 grams of water = 162/18 = 9 mols of water.
So the correct formula is Na2S*9H20
from the equation 2PbO + C = 2Pb + CO2, detemine which one is reactant is oxidised and which is reduced.
Answer:
Explanation:
C is oxidised because C up to C+4
PbO is reduced because PbO from Pb2+ down to Pb0
Answer:
lead (Pb) is reduced carbon is oxidized
A student is asked to convert measurements from meters to millimeters and from millimeters to meters. His answers are
shown in bold in the choices shown below. On which choite did he make a mistake?
9070 mm = 90.7 m
652,222 mm= 652.222 m
37,500 mm = 37.5 m
1.02 x 106 mm = 1020 m
Answer:
The first one
Explanation:
9070 mm = 90.7 m
9070mm is actually equal to 9.07m
what is true about solubility
Explanation:
Solubility is defined as a property of solutes by virtue of which they get dissolved in a favorable solvent. The solute can only be dissolved in any suitable solvent up to a limit at a given temperature. This is a characteristic of the the solute-solvent pairing.
For the metal Mg 109.5g solution HCl 10%. a) Case of metal b) Its properties
Answer:
Explanation:
mg +2hcl=mgcl2 +h2
mhcl=10.95g
nhcl==0.3
nmg=1/2nhcl=0.15
mMg=3.6g
m mgcl2=14.25
What is the standard reduction potential, E, for the half-reaction Al3+ (aq)
3e- -> Al(s)?
Answer:
E° = -1.66 V
Explanation:
The standard reduction potential is also known as the standard electrode potentials and it tries to find the probability that an element will be reduced or undergo reduction.
From activation series online showing the standard reduction potentials for half cells, the standard reduction potential of Al3+ (aq) + 3e- -> Al(s) is;
E° = -1.66 V
(Q008) Two physical properties of minerals both result in smooth, flat surfaces with specific angles between them. The first property is externally visible and is the result of how the mineral forms; the second is inherently internal and is the result of breaking a sample of the mineral. These properties are called
Answer: Crystal habit and cleavage.
Explanation:
When two physical properties of minerals both bring about smooth, flat surfaces that has specific angles between them.such that the first property is externally visible and is the result of how the mineral forms while the second property is internal and is the result of breaking a sample of the mineral, it should be noted that the properties are refered to as the crystal habit and cleavage.
It should be noted that the cleavage refers to the tendency of crystalline materials to be able to split along the structural planes.
What is the solubility of salt at 60°C if 2 gm of the salt is left behind when 7 gm of its saturated solution at that temperature dried?
a) 20
b) 40
c) 60
d) 80
40
Explanation:
because its Saturated
Which group of elements is generally unreactive? O A. Noble gases O B. Halogens O C. Alkali metals D. Nitrogen family
Answer:
Nobles Gases Are the group of elements which are generally unreactive
I Hope its right if not then Sorry, have a wonderful day :)Realiza los cálculos para determinar la cantidad de KOH 90%, que se necesita para preparar 100 ml de solución 1N.
Answer:
6.23 KOH 90% son necesarios
Explanation:
Una solución 1N de KOH requiere 1equivalente (En KOH, 1eq = 1mol) por cada litro de solución.
Para responder esta pregunta se requiere hallar los equivalentes = Moles de KOH para preparar 100mL = 0.100L de una solución 1N. Haciendo uso de la masa molar de KOH y del porcentaje de pureza del KOH se pueden calcular los gramos requeridos para preparar la solución así:
Equivalentes KOH:
0.100L * (1eq / L) = 0.100eq = 0.100moles
Gramos KOH -Masa molar: 56.1056g/mol-:
0.100moles * (56.1056g/mol) = 5.61 KOH se requieren
KOH 90%:
5.61g KOH * (100g KOH 90% / 90g KOH) =
6.23 KOH 90% son necesariosChất tinh khiết là:
A. Có tính chất thay đổi
B. Có lẫn thêm vài chất khác
C. Gồm những phân tử đồng dạng
D. Không lẫn tạp chất
Answer:
The FitnessGram™ Pacer Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The 20 meter pacer test will begin in 30 seconds. Line up at the start. The running speed starts slowly, but gets faster each minute after you hear this signal. [beep] A single lap should be completed each time you hear this sound. [ding] Remember to run in a straight line, and run as long as possible. The second time you fail to complete a lap before the sound, your test is over.
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25. Production is a. Transformation b. Reduction c Consumption d. Valuation
Answer:
a
Explanation:
I think a is the answer because when you produce something you transform it's raw materials to a finished good.
I hope this helps
calculate molarity, molality and mole fraction of 28 percent aqueous solution of a solute with molar mass 11.5 g per mole and density is 1.25 g per mole
Explanation:
Aight, I'mma give tell ya an easy way for this question. look at this Forumla
M=
[tex] \frac{10ad}{m} [/tex]
a explains the percentage of aqueous solution
d is the density
m is the molar mass
right, let's just hop to it
M=10×28×1.25/11.5====> M=30.43
what volume of 2.0 m hcl contains 0.50 mol hcl?
Answer:
the volume of the acid is 250 mL.
Explanation:
Given;
number of moles of the Hcl acid, n = 0.5 mol
concentration of the acid, C = 2.0 M = 2 mol/L
let the volume of the acid = V
The volume of the acid is calculated by applying the following equation;
n = CV
V = n/C
[tex]V= \frac{0.5 \ mol}{2 \ mol/L}[/tex]
V = 0.25 L
V = 250 mL
Therefore, the volume of the acid is 250 mL.
What volume of O2 is required to completely burn 15cm3 of pentane? Equation - C5H12 + O2 - CO2 + H2O.
Answer:
The volume of [tex]\rm O_2[/tex] required would be [tex]120\; \rm cm^{3}[/tex], assuming that both the pentane and the [tex]\rm O_2\![/tex] in this question are ideal gases and are under the same temperature and pressure.
Explanation:
Balance the equation for the reaction:
[tex]\rm ?\; C_{5}H_{12} + ?\; O_2 \to ?\; CO_{2} + ?\; H_{2}O[/tex].
Start by setting the coefficient of the molecule with the largest number of atoms to [tex]1[/tex].
In the combustion of alkanes (including pentane,) consider setting the coefficient of the alkane to [tex]1\![/tex].
[tex]\rm 1\; C_{5}H_{12} + ?\; O_2 \to ?\; CO_{2} + ?\; H_{2}O[/tex].
Number of carbon atoms among the reactants: [tex]5[/tex].
Number of hydrogen atoms among the products: [tex]12[/tex].
By the conservation of atoms, there would need to be the same number of carbon and hydrogen atoms (along with the oxygen atoms) among the products.
Hence, the coefficient of [tex]\rm CO_2[/tex] would be [tex]5[/tex] while the coefficient of [tex]\rm H_2O[/tex] would be [tex]12 / 2 = 6[/tex].
[tex]\rm 1\; C_{5}H_{12} + ?\; O_2 \to 5\; CO_{2} + 6\; H_{2}O[/tex].
There would be [tex]5 \times 2 + 6 \times 1 = 16[/tex] oxygen atoms among the products. Also by the conservation of atoms, there would be the same number of oxygen atoms among the reactants.
Hence, the coefficient of [tex]\rm O_2[/tex] would be [tex]16 / 2 = 8[/tex].
[tex]\rm 1\; C_{5}H_{12} + 8\; O_2 \to 5\; CO_{2} + 6\; H_{2}O[/tex].
The ratio between the coefficient of [tex]\rm O_2[/tex] and [tex]\rm C_{5}H_{12}[/tex] in the balanced equation is:
[tex]\displaystyle \frac{n({\rm O_2})}{n({\rm C_{5}H_{12}})} = \frac{8}{1} = 8[/tex].
In other words, it would take eight [tex]\rm O_2[/tex] molecules to react with one [tex]\rm C_{5}H_{12}[/tex] molecule.
Assume that both [tex]\rm O_2[/tex] and [tex]\rm C_{5}H_{12}[/tex] are ideal gases. Under the same temperature and pressure, the volume of the two gases would be proportional to the number of molecules in each gas:
[tex]\displaystyle \frac{V({\rm O_2})}{V({\rm C_{5}H_{12}})} = \frac{n({\rm O_2})}{n({\rm C_{5}H_{12}})} = \frac{8}{1} = 8[/tex].
In other words, it would take [tex]8\; \rm cm^{3}[/tex] of [tex]\rm O_2[/tex] to react with [tex]1\; \rm cm^{3}[/tex] of [tex]\rm C_{5}H_{12}[/tex] under these assumptions. It would then take [tex]8 \times 15\; \rm cm^{3} = 120\; \rm cm^{3}[/tex] of [tex]\rm O_2\![/tex] to react with [tex]15\; \rm cm^{3}\![/tex] of [tex]\rm C_{5}H_{12}\![/tex].
