The percentage of mercury in the ore : 2.49%
Further explanationGiven
12 g of sample
2.89% HgS
Required
The percentage
Solution
mass of HgS in the ore :
= 2.89% x 12 g
= 0.3468 g HgS
Mass of Hg in HgS :
= (Ar Hg/MW HgS) x mass HgS
= (200.592/232,66 g/mol) x 0.3468
= 0.299 g
% mercury (Hg) in sample(a crude ore) :
= (0.299 g : 12 g) x 100%
= 2.49%
Calculate the Ka for a 0.3 M solution of HA (unknown weak acid) if the pH = 3.65. The reaction can be modelled as HA (aq) + H2O (l) ←→ A- (aq) + H3O+ (aq).
The Ka : 1.671 x 10⁻⁷
Further explanationGiven
Reaction
HA (aq) + H2O (l) ←→ A- (aq) + H3O+ (aq).
0.3 M HA
pH = 3.65
Required
Ka
Solution
pH = - log [H3O+]
[tex]\tt [H_3O^+]=10^{-3.65}=2.239\times 10^{-4}[/tex]
ICE method :
HA (aq) ←→ A- (aq) + H3O+ (aq).
0.3 0 0
2.239.10⁻⁴ 2.239.10⁻⁴ 2.239.10⁻⁴
0.3-2.239.10⁻⁴ 2.239.10⁻⁴ 2.239.10⁻⁴
[tex]\tt Ka=\dfrac{[H_3O^+][A^-]}{[HA]}\\\\Ka=\dfrac{(2.239.10^{-4}){^2}}{0.3-2.239.10^{-4}}\\\\Ka=1.671\times 10^{-7}[/tex]
What must be happening, according to Newton's second law of motion, if a rigid body of unchanging mass is observed accelerating?
A force is being applied to the mass.
A force was once applied but is now not being applied.
The mass must be changing.
No force was or is being applied to the mass.
Answer:
A force is being applied to the mass.
Answer:
A force being applied to the mass is the correct answer
Explanation:
when a magnet is moved alongside a wire, what happens?
A. the electric movement stops
B. the protons move to the correct poles
C. the magnet repels like forces
D. the electrons in the wire begin to flow
Explanation:
D.the electrons in the wire begin to flow
What is the name of this formula MnN?
help pls help URGENT
Answer:
I think you got it right witth g
Explanation:
Ammonium chloride + Potassium hydroxide - Potassium
chloride + Ammonia gas + Water
Which of the following chemical reactions correctly interprets
the chemical word equation above?
а) KCl (aq) + NH3(g) + H20 (1) ► NH4Cl (aq) + KOH (aq)
b) NH4Cl (aq) → KCl (aq) + NH3(g) + H2O (1)
c) NH3 (g) + KOH (aq) → NH3(g) + H20 (1)
d) NH4Cl (aq) + KOH (aq) → KCl (aq) + NH3(g) + H20 (1)
Answer:
d) NH4Cl (aq) + KOH (aq) → KCl (aq) + NH3(g) + H20 (1)
Explanation:
The formula for Amonnium Chloride is NH4Cl.
The formula for Pottasium Hydroxide is KOH.
The formula for Pottasium Chloride of KCL.
The formula for Ammonia gas is NH3.
And as everyone knows the formula of water is H20.
Hope this helps :)
A balanced chemical equation obey the law of conservation of mass. According to this law, the mass can neither be created nor be destroyed. Here NH₄Cl (aq) + KOH (aq) → KCl (aq) + NH₃(g) + H₂0 (1) the correct equation. The correct option is D.
What is a balanced chemical equation?A chemical equation in which the number of atoms of reactants and products are equal on both sides of the equation is defined as the balanced chemical equation. The numbers which are used to balance the chemical equation are called coefficients.
The substances which appear on the left hand side of the equation are called the reactants whereas the substances that appear on the right hand side of the equation are called the products.
The reaction between Ammonium chloride and Potassium hydroxide is given as:
NH₄Cl (aq) + KOH (aq) → KCl (aq) + NH₃(g) + H₂0 (1)
Thus the correct option is D.
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why is the electronic stucture written as 1s 2s 2p 3s 3p 4s. ... ? Shell number 3 can be filled 18 electrons but why isn't 3s 3p 3d written?
Answer:
Explanation:
The notations for electronic structure of the atom is based upon the application of quantum numbers which specifies the order of filling of atomic orbitals by electrons. There are 4 quantum numbers that include...
Principle QN (n) => specifies location of electron as to major energy level or, ring about the atom of interest.
Orbital QN (l) => specifies the shape of the orbital containing the electron
s => sphere => holds 2 electrons
p => figure eight => holds up to 6 electrons
d => overlapping figure eights => holds up to 10 electrons
f => multiple overlapping figure eights => holds up to 14 electrons
The order of filling follows the Aufbau Principle that electrons enter the atomic orbital with the lowest available energy content. This order of filling from low energy to higher energies follows the Aufbau Diagram.
This order theoretically can go to infinity, but the scientific community only knows of 7 major energy levels; i.e., the 7 rows of the periodic table. See attached Aufbau diagram and follow the arrows in order from low energy to high energy. Use superscripts for number of electrons equal to atomic number of element of interest.
H: 1s¹
O: 1s²2s²2p⁴
Al: 1s²2s²2p⁶3s²3p³
Ag: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d⁹
How would one convert 5 decades to months (1 decade = 10 years)?
Answer:
A decade is 10 years. Therefore you must first multiply ten by five to get 50. After you multiply the 12 months in a year by the 50 years. Your answer should be 600
Explanation:
Answer:its d
Explanation:just took it
Which Body system works alone to maintain homeostasis? (pls help)
Answer:
circulatory system
Explanation:
Your circulatory system delivers oxygen-rich blood to your bones. Meanwhile, your bones are busy making new blood cells. Working together, these systems maintain internal stability and balance, otherwise known as homeostasis.
Two ions have a different number of
Answer:
Explanation:
Isotopes differ in the number of neutrons; in ions the number of electrons is different from the number of protons. Isotopes are atoms that have the same number of protons but different numbers of neutrons.
Curicun, named for marie curie, has approximately 25 different isotopes that emit an alpha particle when their nuclei decay. If curium-247, the most abundant nuclide, emit and alpha particle, what daughter nuclide is formed?
Answer: The daughter nuclide formed is Plutonium -243
Explanation:
Alpha Decay: In this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. The mass number is reduced by 4 units and atomic number is reduced by 2 units.
[tex]^A_Z\textrm{X}\rightarrow ^{A-4}_{Z-2}\textrm{Y}+^4_2{\alpha}[/tex]
where A - mass number
Z - atomic number
X and Y are symbols of elements
For alpha decay of curium-247,
[tex]^{247}_{96}\textrm{Cm}\rightarrow ^{243}_{94}\textrm{Pu}+^4_2{\alpha}[/tex]
The daughter nuclide formed is Plutonium -243
Select the answer that lists the radiation waves in order of increasing
energy.
A. Gamma rays, Infrared, Radio waves
B. Radio waves, X-rays, Ultraviolet
C. Visible light, Infrared, X-rays
D. Microwaves, Ultraviolet, X rays
URGENT!! Can someone help me with this?
A sample of oxygen gas has a volume of 2.1 L at 3.6 atm pressure and 200 K temperature.
What would the volume of this sample be at 1.0 atm and 400 K?
Answer:
15.1L
Explanation:
Given parameters:
Initial volume = 2.1L
Initial pressure = 3.6atm
Initial temperature = 200K
Final pressure = 1 atm
Final temperature = 400K
Unknown:
Final volume of the sample = ?
Solution:
To solve this problem, we are going to use the general gas law or the combined gas law which is expressed below:
[tex]\frac{P_{1} V_{1} }{T_{1} } = \frac{P_{2} V_{2} }{T_{2} }[/tex]
P, V and T are pressure, volume and temperature
1 and 2 are the initial and final states
Now;
[tex]\frac{2.1 x 3.6}{200}[/tex] = [tex]\frac{1 x V_{2} }{400}[/tex]
200V₂ = 3024
V₂ = 15.1L
Answer:
15.1L
Explanation:
Given parameters:
Initial volume = 2.1L
Initial pressure = 3.6atm
Initial temperature = 200K
Final pressure = 1 atm
Final temperature = 400K
Unknown:
Final volume of the sample = ?
Solution:
To solve this problem, we are going to use the general gas law or the combined gas law which is expressed below:
P, V and T are pressure, volume and temperature
1 and 2 are the initial and final states
Now;
=
200V₂ = 3024
V₂ = 15.1L
An Amazon box weighs 1000 grams and has a volume of 125 ml, what is its density
Answer:
80
Explanation:
ignore
‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️‼️
Is this right? If not which is it pls
Answer:
i believe it is b as well
Explanation:
10. Which best describes the purpose of food?
A
to kill bacteria
s. to prevent disease
c. to eliminate waste materials
o. to provide fuel for cell processes
Answer:
10. Which best describes the purpose of food? to kill bacteria
. to prevent disease
What percent of total energy consumption in the u.s in 2010 came from hydroelectric power? select the closest answer
Answer:
12% but u can put 8%
Explanation:
A student adds a 3.0 g antacid tablet to 35.0 g of water in a bottle. After the reaction is complete, 37.3 g of liquid remains in the bottle.
How much gas was formed in the reaction?
A. 0.7 g
B. 2.3 g
C. 3.0 g
D. 75.3 g
Answer:
A. 0.7 g
Explanation:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
antacid + water → liquid + gas
3.0 g + 35.0 g = 37.3 g + x
38.0 g = 37.3 + x
x = 38.0 g - 37.3 g
x = 0.7 g
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
In given photosynthesis reaction:
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.
did scientists accept wegeners theory? why or why not?
Answer:
No, scientists did not accept Wegener's theory
Explanation:
In a book titled; "The Origin of Continents and Oceans", published in 1915, Wegener introduced his ideas about the theory of continental drift.
According to his idea, "all the continents were once joined together in an "Urkontinent" before breaking up and drifting to their current positions"(live science).
Though some of his ideas were correct, some of them were also quite wrong. Scientists rejected his idea because he did not detail any mechanism by which the continental drift occurs.
why are there so many producers in the first level of consumers
Answer:
The organisms that eat the producers are the primary consumers. They tend to be small in size and there are many of them. ... Because of this inefficiency, there is only enough food for a few top level consumers, but there is lots of food for herbivores lower down on the food chain.
Explanation:
You have 50 L of CO2 gas at standard temperature and pressure (STP). What would need to be done to the pressure to cut the volume of gas in half?
Answer:
what is this
Explanation:
Answer:
we have to double the pressure.
Explanation:
b/c according to boyle's" the volume of a given mass of gas is inversely proportional to its pressure in a constant temperature.
P1*V1=P2*V2
we have P1=1 atm because it is at STp
V1=50L
V2=25L because we want to cut the volume of the gas in half .
and we can find P2
from the above formula we have P2=P1*V1/V2
P2=1*50/25=50/25=2
so when we doubled the pressure the volume will be halved.
Sodium chloride can be produced from reacting sodium metal with chlorine gas. Carly reacts 2.6 g of sodium with 5.0 g of chlorine gas. She recovers 5.8 g of sodium chloride from the reaction. What is her percent yield? Carly's percent yield is ___ %
Answer:
87.75%
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2Na + Cl₂ —> 2NaCl
Next, we shall determine the masses of Na and Cl₂ that reacted and the mass of NaCl produced from the balanced equation. This can be obtained as follow:
Molar mass of Na = 23 g/mol
Mass of Na from the balanced equation = 2 × 23 = 46 g
Molar mass of Cl₂ = 2 × 35. 5 = 71 g/mol
Mass of Cl₂ from the balanced equation = 1 × 71 = 71 g
Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol
Mass of NaCl from the balanced equation = 2 × 58.5 = 117 g
Summary:
From the balanced equation above,
46 g of Na reacted with 71 g of Cl₂ to produce 117 g of NaCl.
Next, we shall determine the limiting reactant.
This can be obtained as follow:
From the balanced equation above,
46 g of Na reacted with 71 g of Cl₂.
Therefore, 2.6 g of Na will react with = (2.6 × 71)/46 = 4.01 g of Cl₂.
From the calculations made above, we can see that only 4.01 g of Cl₂ at of 5 g given in question reacted completely with 2.6 g of Na. Therefore, Na is the limiting reactant and Cl₂ is the excess reactant.
Next, we shall determine the theoretical yield of NaCl. The limiting reactant will be used to obtain the theoretical yield since all of it is consumed in the reaction.
The limiting reactant is Na and the theoretical yield of NaCl can be obtained as follow:
From the balanced equation above,
46 g of Na reacted to produce 117 g of NaCl.
Therefore, 2.6 g of Na will react to produce = (2.6 × 117)/46 = 6.61 g of NaCl.
Thus the theoretical yield of NaCl is 6.61 g
Finally, we shall determine the percentage yield of NaCl. This can be obtained as follow:
Actual yield of NaCl = 5.8 g
Theoretical yield of NaCl = 6.61 g
Percentage yield =?
Percentage yield = Actual yield /Theoretical yield × 100
Percentage yield = 5.8/6.61 ×100
Percentage yield of NaCl = 87.75%
What involves 2 non metals ionic or covalent bonds
Answer:
A bond forms between two non metals is covalent
Explanation:
For example Chlorine Cl is a non metal bond in Cl - Cl is covalent
Which statement is true of inclusions?
A. They are older than the rocks that contain them.
B. They are younger than the rocks that contain them.
C. They are the same age as the rocks that contain them.
In your own words, explain why we have seasons on Earth. Why do some places have all 4 seasons and others seem to only have 1 or 2?
what happends if you pour 1 litre of water on the surface of the moon?will it bounce? serouse answer please !
Answer:
Explanation:
Diffuse water molecules can persist at the Moon's sunlit surface, as discovered by NASA's SOFIA observatory in 2020. Gradually water vapor is decomposed by sunlight, leaving hydrogen and oxygen lost to outer space. Scientists have found water ice in the cold, permanently shadowed craters at the Moon's poles.
which of the following is a compound A. Iron B. Alloy C. rock salt D. sugar
Answer:
I think iron sorry if its wrong goodluck!
Which of the following describes how metamorphic rock forms?
Answer:
well they form by heat and pressure
Answer:
They form when they are under extreme heat and pressure.
Explanation:
Balance Na2CrO4 + AlPO4
Answer:
2Na3PO4 + Al2(CrO4)3
Explanation:
these are the products
The balanced equation is 3 Na₂CrO₄ + 3 AlPO₄ ⇒ 2 Na₃PO₄ + Al₂(CrO₄)₃.
Let's consider the unbalanced chemical equation that occurs between Na₂CrO₄ and AlPO₄. This is a double displacement reaction.
Na₂CrO₄ + AlPO₄ ⇒ Na₃PO₄ + Al₂(CrO₄)₃
We will balance it using the trial and error method.
First, we will balance Na atoms by multiplying Na₂CrO₄ by 3 and Na₃PO₄ by 2.
3 Na₂CrO₄ + AlPO₄ ⇒ 2 Na₃PO₄ + Al₂(CrO₄)₃
Finally, we get the balanced equation by multiplying AlPO₄ by 3.
3 Na₂CrO₄ + 3 AlPO₄ ⇒ 2 Na₃PO₄ + Al₂(CrO₄)₃
The balanced equation is 3 Na₂CrO₄ + 3 AlPO₄ ⇒ 2 Na₃PO₄ + Al₂(CrO₄)₃.
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which two planets have the same density ?
Answer:
Uranus and Neptune
Explanation: