Answer:
2.44×10²³ molecules
Explanation:
From the question given above, the following data were obtained:
Mass of H₂O = 7.30 g
Number of molecules of H₂O =?
From Avogadro's hypothesis:
1 mole of H₂O = 6.02×10²³ molecules
1 mole of H₂O = (2×1) + 16
= 2 + 16
= 18 g
Thus,
18 g of H₂O = 6.02×10²³ molecules
Finally, we shall determine the number of molecules present in 7.3 g of H₂O. This can be obtained as follow:
From Avogadro's hypothesis:
18 g of H₂O = 6.02×10²³ molecules
Therefore,
7.3 g of H₂O = 7.3 × 6.02×10²³ / 18
7.3 g of H₂O = 2.44×10²³ molecules
Thus, 7.3 g of H₂O contains 2.44×10²³ molecules
45. Which electron configuration represents an
atom in the excited state?
(1) 1s2 2s2 2p6 3s2
(2) 1s2 2s2 2p6 3s1
(3) 1s2 2s2 2p6 (4) 1s2 2s2 2p5 3s2
(4) 1s 2s2p5352
Answer:
The correct answer is - (4) 1s2 2s2 2p5 3s2
Explanation:
An excited state is a state when the valence electron has moved to some other higher energy orbital, from its ground state orbital. The ground state has a lower energy level or sublevel. In this case, the higher energy level orbit fills before the lower energy level.
In option 4, the last electron is filled in higher energy orbit 3s2 before filling the lower or ground energy level 2p5, in the ground state it would be 1s2 2s2 2p6 3s1 instead of 1s2 2s2 2p5 3s2.
Thus, the correct answer is option 4.
N 2H 4 + H202 N2 + H 20
Answer:
N2 + H20
Explanation:
chemical equation balancer
How many grams of Mn are there in 5.09 moles of Mn?
grams
Explanation:
n=m/M
m=n*M
m=5,09 mol * 54,9g/mol
m= 279,4g
[tex]\text{mass of Mn = 5.09 mol Mn} × \frac{\text{54.94 g Mn}}{\text{1 mol Mn}}[/tex]
[tex]\boxed{\text{mass of Mn = 279.6 g}}[/tex]
In scientific notation, the number 0.00262 is expressed as
Answer:
2.62*10^-3
Explanation:
To do this by hand, you need to understand the rules of scientific notation.
Answer:
0.00262 in scientific notation is 2.62 x 10^-3
In order to boil water, Jacy places a pan of water on the burner of a stove. By which process of thermal energy transfer does
the burner transfer heat to the pan?
A conduction
B. convection
C. radiation
D. respiration
Answer:
A campfire is a perfect example of the different kinds of heat transfer. If you boil water in a kettle, the heat is transferred through convection from the fire to the pot.
Explanation:
An object was measured by a worker as
15.9cm long, however, the manufacturer
specifications list the length of the object at
15.8cm. What is the percent error in the
workers measurement?
Answer:.633
Explanation:
I have know idea but it was right
Answer:
O.633%
Explanation:
For all those Acellus kids XD
A mixture of 65 percent N2 and 35 percent CO2 gases (on a mass basis) enters the nozzle of a turbojet engine at 60 psia and 1400 R with a low velocity, and it expands to a pressure of 12 psia. If the isentropic efficiency of the nozzle is 88 percent, determine:
(a) the exit temperature
(b) the exit velocity of the mixture.
Assume constant specific heats at room temperature.
Answer:
a. 969.1 R
b. 2237 ft/s
Explanation:
First the apparent specific heats are determined from the mass fractions of the gases:
[tex]c_{p} &=\left(\mathrm{mf} c_{p}\right)_{\mathrm{N}_{2}}+\left(\mathrm{mf} c_{p}\right) \mathrm{CO}_{2} \\ &=(0.65 \cdot 0.248+0.35 \cdot 0.203) \frac{\mathrm{Btu}}{\mathrm{lbm} \mathrm{R}} \\ &=0.232 \frac{\mathrm{Btu}}{\mathrm{lbmR}} \\ c_{v} &=\left(\mathrm{mf} c_{v}\right)_{\mathrm{N}_{2}}+\left(\mathrm{mf} c_{v}\right)_{\mathrm{CO}_{2}} \\ &=(0.65 \cdot 0.177+0.35 \cdot 0.158) \frac{\mathrm{Btu}}{\mathrm{lbmR}} \\ &=0.170 \frac{\mathrm{Btu}}{\mathrm{lbmR}}[/tex]
The isentropic coefficient then is:
[tex]k &=\frac{c_{p}}{c_{v}} \\ &=\frac{0.232}{0.17} \\ &=1.365[/tex]
The final temperature is determined from the isentropic nozzle efficiency relation:
[tex]T_{2} &=T_{1}-\eta_{N}\left(T_{1}-T_{2 s}\right) \\ &=T_{1}\left(1-\eta_{N}\left(1-\left(\frac{P_{2}}{P_{1}}\right)^{(k-1) / k}\right)\right) \\ &=1400\left(1-0.88\left(1-\left(\frac{800}{100}\right)^{(1.365-1) / 1.365}\right)\right) \mathrm{R} \\ &=969.1 \mathrm{R}[/tex]
b. The outlet velocity is determined from the energy balance:
[tex]h_{1} &+\frac{v_{1}^{2}}{2}=h_{2}+\frac{v_{2}^{2}}{2} \\ v_{2} &=\sqrt{2 c_{p}\left(T_{1}-T_{2}\right)} \\ &=\sqrt{2 \cdot 0.232(1400-969.2) \cdot 25037} \frac{\mathrm{ft}}{\mathrm{s}} \\ &=2237 \frac{\mathrm{ft}}{\mathrm{s}}[/tex]
What is 0.738 × 104? Enter your answer in the box.
_____
6. If 4 grams of salt is dissolved in 79 grams of water, what is the total mass of the final solution? [1 mark]
a) 83g
b)4g
c) 79g
d) 81g
Answer:
A) 83g
Explanation:
Answer:
mass of solution=mass of solute+mass of solvent
=4+79
. =83g
To what temperature must a balloon, initially at 25°C and 2.00 L, be heated in order to have a volume of 6.00 L
Answer:
894 deg K
Explanation:
The computation is shown below:
Given that
V1 denotes the initial volume of gas = 2.00 L
T1 denotes the initial temperature of gas = 25 + 273 = 298 K
V2 denotes the final volume of gas = 6.00 L
T2 = ?
Based on the above information
Here we assume that the pressure is remain constant,
So,
V1 ÷ T1 = V2 ÷ T2
T2 = T1 × V2 ÷ V1
= (298)(6) ÷ (2)
= 894 deg K
Aspirin can be prepared from salicylic acid ( C 7 H 6 O 3 CX7HX6OX3), which has a molar mass of 138.12 g/mol, and acetic anhydride ( C 4 H 6 O 3 CX4HX6OX3), which has a molar mass of 102.04 g/mol. The density of acetic anhydride is 1.082 g/mL. C 7 H 6 O 3 + C 4 H 6 O 3 ⟶ C 9 H 8 O 4 + C 2 H 3 O 2 CX7HX6OX3+CX4HX6OX3⟶CX9HX8OX4+CX2HX3OX2 What is the theoretical yield, in grams, of aspirin ( C 9 H 8 O 4 CX9HX8OX4), which has a molar mass of 180.15 g/mol, possible when reacting 3.20 g of salicylic acid with 3.71 mL of acetic anhydride? Type answer:
Answer: The theoretical yield of aspirin is 4.14 g
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex] [tex]\text{Moles of salicylic acid}=\frac{3.20g}{138.12g/mol}=0.023moles[/tex]
mass of acetic anhydride = [tex]density\times volume =1.082g/ml\times 3.71ml=4.01g[/tex]
[tex]\text{Moles of acetic anhydride}=\frac{4.01g}{102.04g/mol}=0.039moles[/tex]
[tex]C_9H_6O_3+C_4H_6O_3\rightarrow C_9H_8O_4+C_2H_3O_2[/tex]
According to stoichiometry :
1 mole of salycylic acid require 1 mole of acetic anhydride
Thus 0.023 moles of salycylic acid require=[tex]\frac{1}{1}\times 0.023=0.023moles[/tex] of acetic anhydride
Thus salycylic acid is the limiting reagent as it limits the formation of product and acetic anhydride is the excess reagent.
As 1 mole of salycylic give = 1 mole of aspirin
Thus 0.023 moles of salycylic acid give =[tex]\frac{1}{1}\times 0.023=0.023moles[/tex] of aspirin
Mass of aspirin = [tex]moles\times {\text {Molar mass}}=0.023moles\times 180.15g/mol=4.14g[/tex]
Thus theoretical yield of aspirin is 4.14 g
HELP! 20 mL of hydrogen measured at 15°C is heated to 35°C.
What is the new volume at the same pressure?
Answer:either 20.38 or 21.38
Explanation:
i clicked on 10.38 and it was wrong, i also clicked on 22.38 and it was wrong lol
Answer: 21.38 mL
Explanation: i just answered it on ck-12
William Rankine coined this energy from
A. Mechanical energy
B. Kinetic energy
C. Potential Energy
D. Total energy
E. Chemical Energy
Answer:
C.Potential Energy
Explanation:
How much energy would be released as 95.0 g of acetic acid crystallized?
Answer:
-18.54kJ of energy would be released
Explanation:
The enthalpy of crystallization is defined as the heat released when 1 mole of a substance change its state from liquid to solid. The ΔHcrystallization of acetic acid is -11.72kJ/mol (ΔHcrystallization = - ΔHfusion).
To solve this question we must convert the mass of acetic acid to moles in order to find the heat released:
Moles acetic acid -Molar mass: 60.052g/mol-:
95.0g * (1mol / 60.052g) = 1.58 moles
Heat released:
1.58 moles * (-11.72kJ/mol) =
-18.54kJ of energy would be releasedWhat is the volume of 40.0 grams of argon gas at STP ?
Answer:
24.9 L Ar
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableMolesSTP (Standard Conditions for Temperature and Pressure) = 22.4 L per mole at 1 atm, 273 KAqueous Solutions
States of MatterStoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
[Given] 40.0 g Ar
[Solve] L Ar
Step 2: Identify Conversions
[PT] Molar Mass of Ar - 39.95 g/mol
[STP] 22.4 L = 1 mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 40.0 \ g \ Ar(\frac{1 \ mol \ Ar}{39.95 \ g \ Ar})(\frac{22.4 \ L \ Ar}{1 \ mol \ Ar})[/tex][DA] Divide/Multiply [Cancel out units]: [tex]\displaystyle 24.9235 \ L \ Ar[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
24.9235 L Ar ≈ 24.9 L Ar
You have 4.5 x 10^24 particles of C3H8. How many grams are present?
Answer:
33 g.
Explanation:
Hello there!
In this case, for these particle-mole-mass relationships problems, it is necessary for us to recall the following equivalence statement, based off the molar mass of the involved compound, C3H8, one mole of particles and the Avogadro's number:
[tex]1mol=44.11g=6.022x10^{23}molecules[/tex]
In such a way, we can set up the following expression for the calculation of the mass in the given particles of propane:
[tex]4.5x10^{23}molecules*\frac{1mol}{6.022x10^{23}molecules} *\frac{44.11g}{1mol}\\\\33g[/tex]
Best regards!
What is produced when a strong acid reacts with the bicarbonate buffer system in the human body?
O water
O carbonate ions
O bicarbonate ions
O carbonic acid
Answer:
Carbonic acid
Explanation:
The acid reacts with the bicarbonate ion and create carbonic acid
The question is in the photo
Answer:
B
Explanation:
from the diagram.... the population of africa increases so..... ofcourse it exceeds its death rate ....
that's all .... have fun
(4 pts) Fill in the number of protons and electrons for each product and reactant (two boxes have been filled in for you). (2 pts) Verify that the number of protons on the left side of the chemical equation is equal to the number of protons of the right side. Show your work. (2 pts) Verify that the number of electrons on the left side of the chemical equation is equal to the number of electrons of the right side. Show your work. (3 pts) Which substance is being oxidized
Answer:
a)
Zn(s) + 2 H⁺(aq) ⇒ Zn²⁺(aq) + H₂(g)
#p⁺ 30 2 30 2
#e⁻ 30 0 28 2
b) 32
c) 30
d) Zn
Explanation:
There is some info missing. I will add the complete question.
Consider the following oxidation/reduction reaction.
Zn(s) + 2 H⁺(aq) ⇒ Zn²⁺(aq) + H₂(g)
#p⁺ 2
#e⁻ 2
a) Fill in the number of protons and electrons for each product and reactant (two boxes have been filled in for you).
b) Verify that the number of protons on the left side of the chemical equation is equal to the number of protons of the right side. Show your work.
c) Verify that the number of electrons on the left side of the chemical equation is equal to the number of electrons of the right side. Show your work.
d) Which substance is being oxidized?
a) The atomic number of Zn is 30 so it will have 30 protons. Since it ts neutral, it will also have 30 electrons. Zn²⁺ will also have 30 protons but it lost 2 electrons, so it has 28 electrons. The atomic number of H⁺ is 1, so each H atom will have 1 proton (2 in total). But since H has 1 electron, and H⁺ lost 1 electron, H⁺ will have 0 electrons. The complete chart is:
Zn(s) + 2 H⁺(aq) ⇒ Zn²⁺(aq) + H₂(g)
#p⁺ 30 2 30 2
#e⁻ 30 0 28 2
b) The total number of protons on the left side is: 30 + 2 = 32.
The total number of protons on the right side is: 30 + 2 = 32.
c) The total number of electrons on the left side is: 30 + 0 = 30.
The total number of electrons on the right side is: 28 + 2 = 30.
d) Zn(s) is oxidized because it loses electrons (from 30 to 28) and its number increases.
Question 1
Describe a procedure you could follow to determine the specific heat of a 45-g piece of metal.
Instructions
Answer:
2.1 × 10^-8 J/°c
Explanation:
Is this the answer if yes I would explain if not , that's all I know .
When a 58.8-g piece of hot alloy is placed in 125 g of cold water in a calorimeter, the temperature of the alloy decreases by 106.1°C, while the temperature of the water increases by 10.5°C. The specific heat of the alloy is 0.087 J/(g °C).
Step 1: We know that the heat gained by the water is equal to the heat lost by the alloy. This is based on the law of conservation of energy, which states that energy cannot be created or destroyed, only transferred.
Step 2: We can calculate the heat gained by the water using the formula:
q = mcΔT
where:
q = heat energy
m = mass
c = specific heat
ΔT = change in temperature
For water, the specific heat (c) is 4.18 J/(g °C). So, the heat gained by the water is:
q = (125 g)(4.18 J/(g °C))(10.5 °C) = 5497.5 J
Step 3: The heat lost by the alloy is equal to the heat gained by the water. So, the heat lost by the alloy is also 5497.5 J.
Step 4: We can calculate the specific heat of the alloy using the formula:
c = q/(mΔT)
where:
c = specific heat
q = heat energy
m = mass
ΔT = change in temperature
So, the specific heat of the alloy is:
c = 5497.5 J / (58.8 g)(106.1 °C) = 0.087 J/(g °C)
To know more about calorimeter, click here.
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why is nitrogen used for storage of semen in artificial insemination
Answer:
Explanation:
Nitrogen is use to store semen for artificial insemination because if it's inert characteristics which it help to maintain the semen inertness and also it maintain the low temperature of the semen which is good for it's quality.
Nitrogen also help to prevent it's biological deterioration thereby maintaining it's viability and effectiveness.
PLEASE ANSWER!!!!!!!!
Scientists observe the polyatomic ion nitrate forming a compound with unknown element 'A' and predict that the chemical formula could be A2NO3. One of the scientists, Nadeen, states that this chemical formula would be impossible. Is Nadeen correct? Explain why or why not.
Answer:
knflnvwlknnffenfkw
Explanation:
How many moles of aluminum oxide will be produced from 0.50 mol of oxygen?
4 Al + 3 O2→ 2 Al2O3
Answer:
[tex]\boxed {\boxed {\sf \frac {1}{3} \ mol \ Al_2O_3 \approx 0.34 \ mol \ Al_2O_3}}[/tex]
Explanation:
We will use stoichiometry to solve this problem. The reaction given has a formula of
[tex]4Al+3O_2 \rightarrow 2Al_2O_3[/tex]
The coefficients tell us the number of moles necessary for the reaction.
The reaction requires 3 moles of oxygen to produce 2 moles of aluminum oxide. We can make a ratio.
[tex]\frac {3 \ mol \ O_2}{ 2\ mol \ Al_2O_3}}[/tex]
Since we are doing the reaction with 0.5 moles of oxygen, we multiply the ratio by that number.
[tex]0.5 \ mol \ O_2 *\frac {3 \ mol \ O_2}{ 2 \ mol \ Al_2O_3}}[/tex]
Flip the ratio so the moles of oxygen cancel each other out.
[tex]0.5 \ mol \ O_2 *\frac {2 \ mol \ Al_2O_3}{ 3 \ mol \ O_2}}[/tex]
[tex]0.5 *\frac {2 \ mol \ Al_2O_3}{ 3 }[/tex]
[tex]\frac {1 \ mol \ Al_2O_3}{ 3 }[/tex]
[tex]\frac {1}{3} \ mol \ Al_2O_3 = 0.33333 \ mol \ Al_2O_3 \approx 0.34 \ mol \ Al_2O_3[/tex]
0.5 moles of oxygen produces 1/3 or approximately 0.34 moles of aluminum oxide.
What is the hybridization of the central atom in CO2? Hybridization = What are the approximate bond angles in this substance? Bond angles = fill in the blank 2
Answer:
sp
Explanation:
Hybridization is the combination of atomic orbitals to yield equivalent hybrid orbitals of appropriate energy which can participate in bonding.
In every compound there is a central atom. The central atom is usually the least electronegative atom in the molecule. In this case the least electronegative atom in the molecule is carbon.
The bond between carbon and oxygen in CO2 is intermittent between a pure double and a pure triple bond. Hence, carbon is sp hybridized.
All of the following are symptoms of someone having a dissociative disorder except
A. memory loss
B. increased energy
C. distorted perception
D. blurred sense of identity
The symptoms of someone having a dissociative disorder are memory loss, distorted perception and a blurred sense of identity except the increased energy.
What is dissociative disorder?Dissociative disorders are having problems with memory, identifying a person, emotion, perception, behavior changes, and sense of self. It can disrupt mental functioning completely.
Examples of dissociative disorder symptoms are the experience of detachment and loss of memory.
The given examples are all the symptoms of dissociative disorder except the increased energy.
Learn more about dissociative disorder.
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Comprehension Questions:
1. Changing location
change an
object's mass. (does/does not)
O
does
O does not
Answer:
It does not change and object's mass
Write an equation and solve the problem.
3. Dexter buys a package of 38 plates. He already
has 4 plates. He puts an equal number on each of
6 tables. How many plates are on each table?
Americium-241 undergoes radioactive decay to produce neptunium-237. Which particle needs to be added to this equation to show that the total numbers of neutrons and protons are not changed by the reaction?
Answer:
alpha particle needs to be added to the equation.
Explanation:
Given;
atomic mass of Americium = 241
atomic mass of neptunium = 237
The difference in atomic mass of the radioactive elements given is calculated as;
241 - 237 = 4
The particle with atomic mass of 4 is alpha particle usually represented with helium atom.
Am²⁴¹ -----> He⁴ + Np²³⁷
Thus, alpha particle needs to be added to the equation.
Answer:
4/2 HE
Explanation:
a p e x!
Complete the following sentence by choosing the best answer:
Waves transfer ____.
a. particles
b. energy
с. light
d. matter
Answer: it is b give braineless
Explanation:
11. The modern periodic table is arranged in order of increasing atomic
O radius
O charge
O number
O mass
Answer:
number. so the option is c
Answer:
atomic number
Explanation:
i just know it