Answer:
0.24 moles.
Explanation:
number of moles = mass of sample /mass of 1 mole
9.8g /40.08g = 0.2445 moles <3
Which is a correct comparison between the modern quantum model and John Dalton’s model of the atom?
The modern model is not as widely accepted by scientists as Dalton’s model.
The modern model states that atoms of all elements are identical, whereas Dalton’s model does not.
The modern model recognizes particles in the atom, whereas Dalton’s model does not.
The modern model does not explain emission spectra, whereas Dalton’s model does.
Answer:
The modern model recognizes particles in the atom, whereas Dalton’s model does not.
Explanation:
The modern model considers the atom to consist of electrons, protons, and neutrons.
A is wrong. The modern model of the atom is widely accepted.
B is wrong. Dalton assumed that all atoms are identical. The modern model recognizes that there are isotopes of atoms.
D is wrong. The modern model explains emission spectra. Dalton's model does not.
Answer:
C. The modern model recognizes particles in the atom, whereas Dalton’s model does not.
Explanation:
IM JUST HIM
Please can someone help me with this. I am lost and I don't understand how can I do this.
What volume, in L, of 0.219 M NiCl2 solution is required to produce 68.4 g of precipitate.
3NiCl2(aq) + 2Na3PO4(aq) → Ni3(PO4)2(s) + +6NaCl(aq)
Answer:
2.56 L NiCl2
Explanation:
This is a stoichiometry problem. You need to find a way to go from g of Ni3(PO4)2 to L of NiCl2. To do this you travel
mass Ni3(PO4)2 > moles Ni3(PO4)2 > moles NiCl2 > L NiCl2
so you need to know the key that lets you travel from one to the next.
Mass > moles, use molar mass
moles > moles, use the mole ratio
moles > L, use the molarity (moles / liter) in this case. (With gases, you use the STP gas volume of 22.4L / mole).
The attached picture shows what this problem looks like.
The problem requires application of stoichiometry using a balanced chemical equation. About 2.51 L of 0.219 M NiCl2 solution is needed to produce 68.4 g of Ni3(PO4)2 precipitate.
Explanation:The subject of the problem concerns stoichiometry in chemistry. Specifically, the use of a balanced chemical equation to calculate volumes of a solution needed, in this case - 0.219M of NiCl2 solution required to produce 68.4g of Ni3(PO4)2 precipitate.
First, we need to convert the given mass of precipitate (Ni3(PO4)2) to moles. We use the molar mass of Ni3(PO4)2 for this which is roughly 374.09 g/mol. Thus, 68.4g of Ni3(PO4)2 is approximately 0.183 moles.From the balanced chemical equation, we know that three moles of NiCl2 are required to produce one mole of Ni3(PO4)2. So, we need about 0.183 x 3 = 0.549 moles of NiCl2.Finally, we need to determine the volume of a 0.219 M NiCl2 solution that contains 0.549 moles of NiCl2. Using the molarity formula (moles/volume), we find that the volume is approximately 2.51 L.Learn more about Stoichiometry here:https://brainly.com/question/30215297
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What is the limiting reactant in a reaction that produces sodium chloride from 8 g of sodium and 8 g of diatomic chlorine?
Answer:
Cl₂ is the limiting reactant.
Explanation:
Firstly, we need to write the balanced reaction:2Na + Cl₂ → 2NaCl,
It is clear that 2 mol of Na react with 1 mol of Cl₂ to produce 2 mol of NaCl.
Firstly, we need to calculate the no. of moles of 8.0 g Na and 8.0 g Cl₂:For Na:
n = mass/molar mass = (8.0 g)/(22.989 g/mol) = 0.348 mol.
For Cl₂:
n = mass/molar mass = (8.0 g)/(70.9 g/mol) = 0.113 mol.
From the stichiometry: 2 mol of Na react with 1 mol of Cl₂ with (2: 1) molar ratio.The limiting reagent in a chemical reaction is the substance that is totally consumed when the chemical reaction is complete. The amount of product formed is limited by this reagent, since the reaction cannot continue without it.
So, 0.113 mol of Cl₂ react completely with 0.226 mol of Na which be in excess (0.384 - 0.226 = 0.158 mol).
So, the limiting reactant is Cl₂ which is the reactant has the lowest molar ratio.
Diatomic chlorine (Cl₂) is the limiting reactant for the reaction between 8 g of sodium and 8 g of diatomic chlorine.
The limiting reactant in a chemical reaction is simply defined as the reactant which is completely used up in the chemical reaction.
With the above information in mind, we can determine the limiting reactant for the reaction between 8 g of sodium and 8 g of diatomic chlorine (Cl₂). This can be obtained as follow:
2Na + Cl₂ —> 2NaCl
Molar mass of Na = 23 g/mol
Mass of Na from the balanced equation = 2 × 23 = 46 g
Molar mass of Cl₂ = 35.5 × 2 = 71 g/mol
Mass of Cl₂ from the balanced equation = 1 × 71 = 71 g
From the balanced equation above,
46 g of Na reacted with 71 g of Cl₂
Therefore,
8 g of Na will react with = [tex]\frac{8 * 71}{46}\\\\[/tex] = 12.3 g of Cl₂
From the calculation made above, we can see clearly that a higher mass of Cl₂ (i.e 12.3 g) than what was given (i.e 8 g) is needed to react completely with 8 g of Na.
Therefore, Cl₂ is the limiting reactant and Na is the excess reactant.
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Imagine that you have a partially inflated
tire. If you add approximately two
pumps more air into it from your tire
pump, what do you expect to change
when you compare the starting and
ending state of the tire?
A. Volume
B. Temperature
C. Pressure
D. Moles of air molecules
Answer:
volume, pressure, moles of air molecules
Explanation:
The volume, Pressure and Moles of air molecules expect to change when you compare the starting and ending state of the tire.
So, option A , C and D is correct option.
What happen to pressure and volume when more air pumped in the tire?Since, according to Boyle's law, volume is inversely proportional to the pressure.As we pumped more air in the tire then gas molecule compressed and packed together.So, pressure inside the tire increases and volume decreases.As more air pumped in tire then number of moles of air molecule increases.Learn about pressure , volume and moles
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how many molecules of carbon dioxide are in 3.2 moles of carbon dioxide
Answer:
1.93 x 10²⁴molecules
Explanation:
Given parameters:
Number of moles of CO₂ = 3.2 moles
To find the number of molecules of CO₂ in 3.2 moles, we simply use the expression below :
Number of particles = number of moles x 6.02 x 10²³
The above equation relates the number of particles such as molecules, atoms, protons, electrons to the number of moles.
A mole can be defined as the amount of substance contained in the avogadro's number of particles(6.02 x 10²³)
Number of particles = 3.2 x 6.02 x 10²³ = 19.264 x 10²³ =
1.93 x 10²⁴molecules
In 3.2 moles of CO₂, there are approximately 1.92624 × 10²⁴ molecules.
The number of molecules of carbon dioxide in 3.2 moles can be calculated by using Avogadro's number. Avogadro's number is 6.022 × 10²³ molecules per mole.
Therefore, in 3.2 moles of CO₂, there are 3.2 x 6.022 × 10²³ = 1.92624 × 10²⁴ molecules of CO₂.
The table shows the specific heat of four substances—brick, dry soil, paper, and water. If all four substances were exposed to sunlight for the same amount of time, which substance would heat up the fastest?
brick 0.9
dry soil 1.26
paper 1.336
water 4.18
Answer:
Brick.
Explanation:
The formula for the amount of heat absorbed by an object is
q = mCΔT
You want to know how much ΔT changes for each object.
[tex]\Delta T=\dfrac{q}{mC}[/tex]
If each object has the same mass and absorbs the same amount of heat, then
[tex]\Delta T \propto \dfrac{1}{C}[/tex]
The object with the smallest specific heat capacity should have the greatest temperature increase.
Brick will have the greatest temperature increase (we can't say how fast the objects will heat up, because that depends on thermal conductivity: how quickly the heat is carried to the interior of the object).
Answer: Brick
Explanation:
Because any number is the lowest in this question it would be brick
Is the ability to tarnish a physical or chemical property
Is the ability to freeze a physical or chemical property
Is the ability to rust a physical or chemical property
Answer:
[tex]\boxed{\text{Chemical; physical; chemical}}[/tex]
Explanation:
Tarnish ing
Tarnishing is a chemical property.
One substance changes into another substance with different properties. For example, the tarnish on silverware is formed by the reaction of silver with hydrogen sulfite to form black silver sulfide.
2Ag + H₂S ⟶ Ag₂S + H₂
Freezing
Freezing is a physical property, because the composition of the substance does not change. After liquid water has frozen to ice, it is still water, but in the solid state.
H₂O(ℓ) ⇌ H₂O(s)
Rusting
Rusting is a chemical property, because a new substance with different properties is formed.
A simple equation for the formation of rust is
2 Fe + 3O₂ + H₂O ⟶ Fe₂O₃·H₂O
several factors that effect the rate of a rection. in this investigation you will design experiments to test three factors that may effect the reaction.
answer:
temperature
pressure
volume
concentration of amount of reactants and product
What kind of bond is formed between the two atoms below? Justify your reasoning.
The bond formed here would be a covalent bond.
This is because not only are the two molecules (Chlorine) listed nonmetals, but they also have identical electronegativity values. (Both have 7 electrons.)
Hope I could help! :)
Why resolution power in TEM microscope is higher than SEM microscope
Answer:
Here's what I get.
Explanation:
Two factors:
1. Higher accelerating voltages
Both types use a beam of accelerated electrons as a source of illumination.
Resolution depends on the wavelength of the electron beam. The shorter the wavelength, the smaller the objects you can "see."
SEMs usually use acceleration voltages up to 30 kV, while TEMs can set them as high 300 kV. Thus, the electron wavelengths in TEMs are shorter by a factor of 10.
2. Less spherical aberration
Spherical aberration degrades the quality of the image. It decreases as wavelength decreases, so you can push the magnification higher with a TEM without losing image quality.
Answer:
idfk
Explanation:
Which substance is an Arrhenius acid?
a. H2
b.HCI
c. KCI
d, NH,3
Answer:
Hcl
Explanation:
Arrhenius acid - produce H+
Arrhenius base - produce oh -
we can see here in the option B give us H+ which is arrhenius acid
HCl is an Arrhenius acid. Hence, option B is correct.
What is an Arrhenius acid?According to Arrhenius's theory, acid is a substance that gives[tex]H^+[/tex] ion on dissolving in the aqueous solution.
It increases the concentration of [tex]H^+[/tex] ions in the solution.
The base is a substance that ionizes[tex]OH^-[/tex] ions by dissolving in the aqueous solution.
Arrhenius acid - produce [tex]H^+[/tex]
Arrhenius base - produce [tex]OH^-[/tex]
Hence, option B is correct.
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when 45 g of an alloy, at 25°C, are dropped into 100.0g of water, the alloy absorbs 956J of heat. If the temperature of the alloy is 37°C, what is its specific heat?
A. 0.423 cal/g°C
B. 1.77 cal/g°C
C. 9.88 cal/g°C
D. 48.8 cal/g°C
Please try and explain with step by step or show work, thank you!!
You can use this formula to help:
[tex]c = \frac{q}{m \: \times \: change \: in \: t} [/tex]
Where:
C = specific heat
q = heat
m = mass
t = temperature
What we know:
C = unknown
q = 956 J
m = 45 g
change in t = 12°C because 37°C - 25°C = 12°C
Plug known values into the formula:
C = 956 J / (45 g) (12°C) and we are left with a specific heat of 1.77J/g°C
Now, convert Joules to calories and then you get:
Answer: A. 0.423 cal/g°C
If the temperature of the alloy is 37°C, 0.423 cal/g°C. is its specific heat. The correct answer is A.
To find the specific heat of the alloy, we can use the formula:
Q = mcΔT
where:
Q = heat absorbed (in joules)
m = mass of the alloy (in grams)
c = specific heat of the alloy (in cal/g°C)
ΔT = change in temperature (in °C)
We are given Q = 956 J, m = 45 g, ΔT = (37°C - 25°C) = 12°C. Now, we need to convert the heat and temperature from joules to calories:
1 cal = 4.184 J
Q = 956 J * (1 cal / 4.184 J) = 228.74 cal
Now, we can rearrange the formula to solve for c:
c = Q / (m * ΔT) = 228.74 cal / (45 g * 12°C) ≈ 0.423 cal/g°C
Therefore, the correct answer is A. 0.423 cal/g°C.
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Suppose you have a solution of NaOH of unknown concentration. Name three
possible substances that could be used as "titrant" solutions to titrate the NaOH
solution.
Final answer:
To determine the concentration of NaOH in a solution, you can use titrants such as Hydrochloric acid (HCl), Sulfuric acid (H2SO4), or Potassium hydrogen phthalate (KHP) through the titration process.
Explanation:
In order to determine the concentration of NaOH in a solution, you can use a process called titration with a titrant. Three possible titrant solutions that can be used to titrate an NaOH solution include:
Hydrochloric acid (HCl)Sulfuric acid (H2SO4)Potassium hydrogen phthalate (KHP)Each of these substances can act as an acid to neutralize the basic NaOH solution, and through the process of titration, you can determine the exact concentration of NaOH presented in the solution.
f a hypothesis can stand the test of repeated examination, it can become a _____.
Answer:
theory
If it has been tested enough, then it can be considered a scientific theory.
The gas usually filled in the electric bulb is
A. nitrogen
B. hydrogen
C. carbon dioxide
D. oxygen
Washing soda is the common name for
A. Sodium carbonate
B. Calcium bicarbonate
C. Sodium bicarbonate
D. Calcium carbonate
View Answer Discu
Answer:
1st answer: A. nitrogen
2nd answer: A. Sodium carbonate
Explanation:
The gas usually filled in the electric bulb is
OPTION A
Washing soda is the common name for
OPTION A
An expandable container of oxygen gas has a volume of 125 mL and a temperature of 25.0ºC. What volume will the gas occupy at 55°C?
Answer:
148.1 mL.
Explanation:
We can use the general law of ideal gas: PV = nRT.where, P is the pressure of the gas in atm.
V is the volume of the gas in L.
n is the no. of moles of the gas in mol.
R is the general gas constant,
T is the temperature of the gas in K.
If n and P are constant, and have different values of V and T:(V₁T₂) = (V₂T₁)
Knowing that:
V₁ = 125 mL, T₁ = 25°C + 273 = 298 K,
V₂ = ??? mL, T₂ = 55°C + 273 = 353 K,
Applying in the above equation(V₁T₂) = (V₂T₁)
∴ V₂ = (V₁T₂)/(T₁) = (125 mL)(353 K)/(298 K) = 148.1 mL.
need help with 14 and 16 pls asap!! this is my friends test and im taking it tomorrow!!
Answer:
Q14: 17,140 g = 17.14 kg.
Q16: 504 J.
Explanation:
Q14:
To solve this problem, we can use the relation:Q = m.c.ΔT,
where, Q is the amount of heat absorbed by ice (Q = 3600 x 10³ J).
m is the mass of the ice (m = ??? g).
c is the specific heat of the ice (c of ice = 2.1 J/g.°C).
ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = 100.0°C - 0.0°C = 100.0°C).
∵ Q = m.c.ΔT
∴ (3600 x 10³ J) = m.(2.1 J/g.°C).(100.0°C)
∴ m = (3600 x 10³ J)/(2.1 J/g.°C).(100.0°C) = 17,140 g = 17.14 kg.
Q16:
To solve this problem, we can use the relation:Q = m.c.ΔT,
where, Q is the amount of heat absorbed by ice (Q = ??? J).
m is the mass of the ice (m = 12.0 g).
c is the specific heat of the ice (c of ice = 2.1 J/g.°C).
ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = 0.0°C - (-20.0°C) = 20.0°C).
∴ Q = m.c.ΔT = (12.0 g)(2.1 J/g.°C)(20.0°C) = 504 J.
Which is capable of housing while they conduct research
A rover
A satellite
A space station
A space observation
Answer:
A space station
Explanation:
A space station provides an avenue for scientist to orbit the space and carryout scientific findings. Most space stations are usually controlled under agreement between different countries. The international space station is one such example.
A rover is usually a robotic device that has been pre-programmed and equipped with state of the art devices to carryout explorations on their own.
Most space observations are usually powerful telescopes on the earth surface that monitors events in space.
A satellite is a body that orbits another.
Answer:
space station
Explanation:
How many yards are in 2.28 meters
Which acids have hydro- as part of their name
Answer: HBr & HF are correct on edmentum/ plato
Explanation:
All acids that start with the prefix "hydro" are also called binary acids. HCl containing anionic chloride is called hydrochloric acid. HCN containing hydrogen cyanide is called hydrocyanic acid
Which acid is not hydrocyanic acid?H2SO3 is not sulfite. Description: Acids containing non-metal elements other than hydrogen and oxygen are called hydrogen acids. Examples: HCl, HBr, HI.
A diprotic acid is an acid composed of hydrogen and one other element. The most common diprotic acids contain halogens. Acid names start with the prefix hydro-.
Acid has its own nomenclature. If the acid is composed of only hydrogen and one other element, its name is water- + stem of another element + -acid. For example, the compound HCl (aq) is hydrochloric acid, while H2S (aq) is hydrogen sulfide.
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