Answer:
the packing efficiency is 52.36%
Explanation:
Given the data in the question;
simple cubic unit cell that contains one atom with a metallic radius of 175 pm;
we know that;
Edge length of Simple cubic (a) is related to radius of atom (r) as follows;
a = 2r
since radius r = 175 pm
we substitute
a = 2 × 175 pm
a = 350 pm
Now we get the volume unit;
Volume of unit cell = a³ = ( 350 pm ) = 42875000 pm³
Next we get Volume of sphere;
Volume of Sphere = [tex]\frac{4}{3}[/tex]πr³
Volume occupied by 1 atom = [tex]\frac{4}{3}[/tex] × π × ( 175 pm )³
= [tex]\frac{4}{3}[/tex] × π × 5359375 pm³
= 22449297.5 pm³
Now, the packing efficiency = ( Volume occupied by 1 atom / Volume of unit cell ) × 100
we substitute;
packing efficiency = ( 22449297.5 pm³ / 42875000 pm³ ) × 100
= 0.523598 × 100
= 52.36%
Therefore, the packing efficiency is 52.36%
Please answer these quickly. :)
Q.1
a) 1 mol of N2 requires 3 moles of H2
so 4 moles of hydrogen will require = 4/3 = 1.33 moles
Answer of A) 1.33 moles
b) 2.5 moles of nitrogen gas were require to produce 5.00 moles of NH3
c) 7.5 moles of hydrogen gas were require to produce
5.00 moles of NH3
Q.2
a) 6 moles of H2 gas were require to make 6.00 mol H2S
b)24 moles of H2 gas were required to react with 3 moles of S8
c)56 moles of H2S are produced from 7 mol of S8
Which best explains the relationship between evaporation and temperature?
• A liquid evaporates slower at lower temperatures because the molecules are more spread apart and are not pushed
as easily from the liquid's surface.
O A liquid evaporates faster at lower temperatures becaus the attractions are decreased and more particles can
escape the surface of the liquid.
© A liquid evaporates slower at higher temperatures because the vapor pressure of the liquid is higher, SO fewer
molecules can escape the surface.
• A liquid evaporates faster at higher temperatures because more particles have a higher speed and can overcome
attractions in the liquid.
Answer: D
Explanation:
liquid evaporates faster at higher temperatures because more particles have a higher speed and can overcome attractions in the liquid.
Answer:
D. A liquid evaporates faster at higher temperatures because more particles have a higher speed and can overcome attractions in the liquid.
Explanation:
Correct on Edge 2022!!!
Good luck everyone, you got this! Have a great day!
If 15L of neon is at 25C is allowed to expand to 45L. What is the new temperature to maintain constant pressure?
Answer:
[tex]T_2=894.45K=621.30\°C[/tex]
Explanation:
Hell there!
In this case, according to the given information, it turns out possible for us to calculate the new temperature by applying the Charles' law as a directly proportional relationship between temperature and volume:
[tex]\frac{V_2}{T_2} =\frac{V_1}{T_1}[/tex]
Thus, we solve for the final temperature, T2, as shown below (make sure T1 is in Kelvins):
[tex]T_2=\frac{V_2T_1}{V_1} \\\\T_2=\frac{(25+273.15)K*45L}{15L}\\\\T_2=894.45K=621.30\°C[/tex]
Regards!
Which term below describes the study of how energy is transferred to
different locations and forms?
A. Thermodynamics
O B. Entropy
C. Enthalpy
D. Chemical reactions
please help me with Chem I ONLY HAVE 5 MINUTES if methane gas (CH4) flows at a rate of 0.25L/s, how many grams of methane gas will there be in a room after 1 hour of time has passed?
Answer:
643g of methane will there be in the room
Explanation:
To solve this question we must, as first, find the volume of methane after 1h = 3600s. With the volume we can find the moles of methane using PV = nRT -Assuming STP-. With the moles and the molar mass of methane (16g/mol) we can find the mass of methane gas after 1 hour as follows:
Volume Methane:
3600s * (0.25L / s) = 900L Methane
Moles methane:
PV = nRT; PV / RT = n
Where P = 1atm at STP, V is volume = 900L; R is gas constant = 0.082atmL/molK; T is absolute temperature = 273.15K at sTP
Replacing:
PV / RT = n
1atm*900L / 0.082atmL/molK*273.15 = n
n = 40.18mol methane
Mass methane:
40.18 moles * (16g/mol) =
643g of methane will there be in the roomThe boiling point of Kelvin scale is:
a) 237º K
b) 100°C
c) 100°K
d) 373°
Answer:
The boiling point of Kelvin scale is: 373° k
hope it is helpful to you
A sample of sodium reacts completely with 0.497 kg of chlorine, forming 819 g of sodium chloride. What mass of sodium reacted?
Express your answer to three significant figures and include the appropriate units.
Answer:
[tex]819 \: g = 819 \times {10}^{ - 3} \: kg = 0.819 \: kg \\ 0.819 \: kg - 0.497 \: kg \\ = 0.322 \: kg[/tex]
The compound AlP (aluminum phosphide) is a compound semiconductor having mixed ionic and covalent bonding. Calculate the fraction of bonding that is ionic.
Answer:
0.086
Explanation:
The formula for calculating the fraction of a covalent bond can be expressed as:
= exp (-0.25ΔE²)
[tex]= exp[-0.25(E_{Al}-E_{p})^2]---(1)[/tex]
from the equation above;
[tex]E_{Al}[/tex] = the electronegativity of aluminum
[tex]E_P[/tex] = electronegativity of phosphorus
Using the data from periodic table figures;
[tex]E_{Al}[/tex] = 1.5
[tex]E_P[/tex] = 2.1
∴
fraction of the covalent = exp[-0.25(1.5 - 2.1)²]
fraction of the covalent = exp(-0.09)
fraction of the covalent = 0.914
Now, the fraction of ionic bond will be = 1 - the fraction of covalent bond
= 1 - 0.914
∴
the fraction of bond that is ionic = 0.086
Name the following alkene:
CH3CH = CHCH2CH3
A. 3-pentane
B. 2-pentene
C. 2-pentane
D. 3-pentene
Answer:
2-pentene
Explanation:
The name of the alkene is 2 pentene. The correct option is B, 2-pentene.
What is 2-pentene?Alkenes with the chemical formula [tex]C_5H_10[/tex] are known as pentene. Within its molecular structure, each has one double bond.
The given alkene [tex]CH_3CH = CHCH_2CH_3[/tex] is 2-pentene because the double bond is present in the second carbon and it's pentene because there are five carbons present.
Thus, the correct option is B. 2-pentene.
Learn more about 2-pentene
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What is the thermal efficiency of an engine that takes n moles of diatomic ideal gas through the cycle
Answer:
The thermal efficiency of an engine is [tex]0.15[/tex] that is 15%
Explanation:
Specific heat of a gas at constant volume is
[tex]C_{v}=\frac{fR}{2}[/tex]
here, [tex]f=[/tex]degree of freedom
[tex]R=[/tex]universal gas constant
Thermal efficiency of a cycle is
[tex]\frac{total workdone}{gross heat absorbed}[/tex]
Gross heat absorbed is amount of heat that absorbed.
ω[tex]=P_{o} V_{o}[/tex]
[tex]Q_{AB}=[/tex]Δ[tex]V_{AB}+[/tex]ω[tex]_{AB}[/tex][tex]=nC_{v}(T_{f}-T_{i} )[/tex]
[tex]=n\frac{f}{2}(RT_{f}-RT_{i} )[/tex][tex]=\frac{f}{2}(P_{o}V_{o} )[/tex]
[tex]Q_{BC}=n(\frac{f}{2}+1 )R(T_{f}-T_{i} )[/tex]
[tex]=(\frac{f}{2} +1)(4P_{o}V_{o}-2P_{o}V_{o} )[/tex]=[tex]=(\frac{f}{2}+1)2P_{o}V_{o}[/tex]
[tex]Q_{CD}=-ve and Q_{DA}=-ve[/tex] these 2 are not the part of gross heat
η[tex]=\frac{P_{o}V_{o} }{(\frac{3f}{2}+2 )(P_{o}V_{o})}[/tex]
[tex]=\frac{1}{(\frac{3f}{2}+2 )}[/tex]
For monoatomic gas [tex]f=3[/tex]
η[tex]=\frac{2}{13}[/tex]
[tex]=0.15[/tex]
How many neutrons are in an atom of argon–40?
Answer:
22 neutrons
Explanation:
If so please sorry
which best describes the type of titration for the graph below? O strong acid titrated with a strong base
O strong base titrated with a strong acid
O weak acid titrated with a strong base
O weak base titrated with a strong acid
Answer:
B. strong base titration with a strong acid
What will occur when potassium reacts with sulfur?
If it takes 720. mL of 0.00125 M Mg(OH)2 to neutralize 425 mL of an HCI
solution, what is the concentration of the HCI? Mg(OH)2 + HCl →MgCl2
+ H20
Answer:
0.004235 M
Explanation:
The neutralization reaction of this question is given as follows:
Mg(OH)2 + 2HCl → MgCl2 + 2H2O
Using the formula below:
CaVa/CbVb = na/nb
Where;
Ca = concentration of acid (M)
Cb = concentration of base (M)
Va = volume of acid (mL)
Vb = volume of base (mL)
na = number of moles of acid = 2
nb = number of moles of base = 1
From the information provided in this question;
Ca = ?
Cb = 0.00125 M
Va = 425 mL
Vb = 720 mL
na (HCl) = 2
nb = (Mg(OH)2) = 1
Using the formula; CaVa/CbVb = na/nb
Ca × 425/0.00125 × 720 = 2/1
425Ca/0.9 = 2
472.2Ca = 2
Ca = 2/472.2
Ca = 0.004235 M
How many grams of BaPO3 are present in a 3.8 mole sample?
Explanation:
M(Bapo3) = 216m/mol
n = 3.8 mole
m = M × n = 216 × 3.8 = 820.8g
Qualitatively explain the effect of changing concentration of Cu2+ on voltage using your experimental observations and the Keq values below. (No calculations are required).
(a) Cu^2+(aq) + 4NH3(aq) ⇄ [Cu(NH^3)4]^2+(aq) Keq = 1.2 x 10^12
(b) CuS(s) ⇄ Cu^2+(aq) + S^2-(aq) , Keq = 8.5 x 10^-45
Cu/Zn = 0.525 V
after 1 drop NH3: 0.505 V
after 2 drops NH3: 0.435 V
Cu/Zn = 0.510 V
after 1 drop Na2S: 0.452 V
after 2 drops Na2S: 0.393 V
When a balloon containing 635 mL of air is taken from sea level (at standard pressure) to a higher altitude, the balloon expands to 829 mL. What is the air pressure at this new altitude (in atm)?
Answer:
0.766atm
Explanation:
Boyles law
P1V1=P2V2
1×635=P2×829
P2=635/829
P2=0.766atm
Carbon dioxide had how many nonbonding electron pairs in its electron arrangement?
A. 2
B. 4
C. 8
D. 6
E. 3
Answer: A.) 2 is the answer.
Explanation:
Calculate ΔG∘rxn at 298 K for the following reaction:
I2(g)+Br2(g)⇌2IBr(g)Kp=436
The change in free energy can help us to discover whether a reaction can be sponteanous or not. The change in free energy fro this reaction is -1.51 kJ/mol.
What is change in free energy?The change in free energy is referred to as that which determines the spontenity of a chemical reaction. For a spontenous reaction the change in free energy must be negative.
Now;
ΔG = -RTlnK
R = gas constant
T = temperature
K = equilibrium constant
So;
ΔG = -(8.314 * 298 * ln 436)
ΔG = -1.51 kJ/mol
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NEED HELP ASAP
Question 7 (5 points)
(05.05 MC)
A synthesis reaction takes place when carbon monoxide (CO) and hydrogen gas (H2) react to form methanol (CH3OH). How many grams of
methanol are produced when 7.0 grams of carbon monoxide reacts with excess hydrogen gas? (5 points)
20 grams
7.0 grams
8.0 grams
6.1 grams
Explanation:
Write the balance equation for the reaction taking place:
CO(g) + 2H2(g) ==> CH3OH ... balanced equation
Find the limiting reactant:
moles CO present = 14 g x 1 mol CO / 28 g = 0.5 moles COmoles H2 present = 1.5 g x 2 mol H2 / 2 g = 0.75 moles H2OBecause according to the balanced equation it takes 2 moles H2 for every 1 mole CO, there isn't enough H2, so it is limiting and will dictate how much CH3OH can be made.
Mass of CH3OH produced = 0.75 moles H2 x 1 mol CH3OH / 2 mol H2 x 32 g CH3OH / mol = 12 g CH3OH
How to do 3 and 4 questions
Answer:
3) Q = -836.8 J.
4) Q = 950J.
Explanation:
Hello there!
In this case, for those calorimetry problems, we use the general equation:
[tex]Q=mC\Delta T[/tex]
Thus, we proceed as follows:
3) Here, the temperature difference is from 80 °C to 40 °C, the mass is 5.0 g and the specific heat 4.184 in SI units; thus, the heat is calculated as follows:
[tex]Q=(5g)(4.184\frac{J}{g\°C} )(40\°C-80\°C)\\\\Q=-836.8J[/tex]
4) Here, the temperature difference is from 100 °C to 200 °C, the mass is 5.0 g and the specific heat about 1.90 in SI units; thus, the heat is calculated as follows:
[tex]Q=(5g)(1.90\frac{J}{g\°C} )(200\°C-100\°C)\\\\Q=950J[/tex]
Regards!
What is the general form for the simplest type of acid-base reaction?
O A. Acid + base > H+ + OH-
B. Acid + base → base + acid
C. Acid + base + salt + water
D. Acid + base → solid + water
Answer:
Your answer is C
Explanation:
When an acid and base react, the acidic hydrogen ion and the basic hydroxide ion in each acid and base neutralize each other and form water. Meanwhile the conjugate base and conjugate acid (the leftover compounds) react to form an ionic molecule, or a salt. (In chemistry, when an anion and a cation form an ionic bond the new molecule is called a salt). Hope this helps!
Pbo.....
= 2Pb +......
Answer:
It's
Explanation:
Pbo + c
= pb + co2
While balancing it becomes
2pbo + c = 2pb + co2
(I was also doing same qn)
You dissolve 14 g of [tex]Mg(NO_{3} )_{2}[/tex] in water and dilute to 750 mL. What is the molarity of this solution?
Show your work
How many molecules of sodium fluoride (NaF) are found in 7.2 moles of sodium fluoride?
Answer:
well please answer me it's question too after you get it
Explanation:
i am also stucked in that question
No. of molecules of any substance is one mole
= Avogadro's Number = (6.022 x 10^23)
So, no. of molecules in 7.2 moles of sodium fluoride
= 7.2 × (6.022 x 10^23)
= 4.33584^24
help ! thank u / ill give brainlist !
Give two examples of energy transformations that occur throughout the journey to or on the planet.
Answer:
Our bodies convert chemical energy in our food into mechanical energy for us to move.
An electric fan transforms electrical energy into kinetic energy
Reword it tho
Hope this helps!!
PPLLLLLZZZZZ HELPPPPPPPPP ME WITH THIS QUESTION BRAINLIEST PLUS 20 POINTS If CO2 was added to this system what would the outcomes for this reaction be?
CO2 + H2O <-> H2CO3
Question 4 options:
It would shift to the right, favor the forward reaction and the rate of reaction would decrease.
It would shift to the left, favor the forward reaction and the rate of reaction would increase.
It would shift to the right, favor the forward reaction and the rate of reaction would increase.
It would shift to the left, favor the reverse reaction and the rate of reaction would decrease.
It would shift to the right, favor the forward reaction and the rate of reaction would increase.
(third option)
is a glow stick Endothermic or exothermic ?
Answer:
exothermic
Explanation:
Consider the energy diagram below.
A graph of reaction progression on the horizontal axis versus energy on the vertical axis. A line starts flat low on the vertical axis, the flat area is labeled A. It rises sharply to peak, labeled C, then falls a short distance before levelling off, labeled D. A dotted line follows the initial line in all respects except that it peaks higher directly above C; that peak is labeled B.
Which statement best describes the diagram?
A. The pathway A-B-D involves a catalyst and is slower than A-C-D.
B. The pathway A-B-D involves a catalyst and is faster than A-C-D.
C. The pathway A-C-D involves a catalyst and is slower than A-B-D.
D. The pathway A-C-D involves a catalyst and is faster than A-B-D.
Answer:
Explanation:
Thank you for providing the graph which was missing in the question!
D is the correct answer because a catalyst will speed up a chemical reaction. In an exothermic reaction as shown, the catalyst also enhances the reaction so that more energy is given out.
D. The pathway A-C-D involves a catalyst and is faster than A-B-D.
because a catalyst will speed up a chemical reaction.
In an exothermic reaction as shown, the catalyst also enhances the response so that more energy is given out.
What is a catalyst?A catalyst is a substance that speeds up a chemical reaction or lowers the temperature or pressure needed to start one, without itself being consumed in the course of the reaction. Catalysis is the process of adding a catalyst to facilitate a reaction.
A chemical catalyst is a substance that causes a chemical reaction to take place in a special way than it would happen without that catalyst. as an example, a catalyst should cause a reaction between reactants to happen at a faster rate or at a lower temperature than would be possible without the catalyst.
Learn more about catalysts here
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HELP ME ASAP PLEASE
I need the answers I’m in a hurry
Answer: First box----Hail
Second Box-------Snow
Thrid Box-------Sleet
Forth Box-----Rain
Hope that helped! :)