The question is: If 40 g of a compound C6H10O5 are dissolved in 500 g of water, determine the boiling point of this solution. (Water: boiling temperature 100 ° C and Kb = 0.52 ° C / m).
Answer: The boiling point of given solution is [tex]100.256^{o}C[/tex].
Explanation:
Given: Mass of solute = 40 g
Mass of solvent = 500 g (1 g = 0.001 kg) = 0.5 kg
[tex]K_{b} = 0.52^{o}C/m[/tex]
Molality is the moles of solute present in kg of solvent.
Moles is the mass of substance divided by its molar mass. Hence, moles of [tex]C_{6}H_{10}O_{5}[/tex] (molar mass = 162.141 g/mol) is calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{40 g}{162.141 g/mol}\\= 0.246 mol[/tex]
Now, molality of the solution is calculated as follows.
[tex]Molality = \frac{molesof solute}{mass(in kg)}\\= \frac{0.246}{0.5 kg}\\= 0.492 m[/tex]
The boiling point is calculated as follows.
[tex]\Delta T_{b} = K_{b}m[/tex]
where,
m = molality
Substitute the values into above formula as follows.
[tex]\Delta T_{b} = K_{b}m\\= 0.52^{o}C/m \times 0.492 m\\= 0.256^{o}C[/tex]
As the boiling point of water is 100 degree Celsius. So, the boiling point of solution is as follows.
[tex](100 + 0.256)^{o}C\\= 100.256^{o}C[/tex]
Thus, we can conclude that the boiling point of given solution is [tex]100.256^{o}C[/tex].
An iron block of mass 18 kg is heated from 285 K to 318 K. If 267.3 kJ is required, what is the specific heat of iron?
A. 490.05
B. 158.77
C. 145.80
D. 450.00
Answer:
D. 450 J/kgK
Explanation:
Using the formula as follows:
Q = m × c × ∆T
Where:
Q = amount of heat absorbed/released (J)
m = mass of substance (g)
c = specific heat capacity
∆T = change in temperature (°C)
According to the information provided in this question:
Q = 267.3 kJ = 267300J
m = 18kg
∆T = 318K - 285K = 33K
c = ?
Q = m × c × ∆T
c = Q ÷ m∆T
c = 267300 ÷ 18 × 33
c = 267300 ÷ 594
c = 450 J/kgK
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19. place moth balls in the closet and observe after several days.
20. whenever wax or a candle burns it turns from solid to liquid but again at room temperature it turns to solid
21. evaporation, condensation, precipitation
22. it produces new substances
23. vinegar Bubbles when baking soda is added
24. steam
Why is the average atomic mass used when calculating grams of a
substance?
A. The exact weights of the isotopes are not known.
B. The elements in the substance are mixtures of their isotopes.
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C. The average atomic mass is known to more significant figures.
D. The number of isotopes in the sample is constantly changing.
Answer:
The average atomic mass includes all of the isotopes of that atom which exist in nature. Almost all elements have at least two isotopes which naturally occur. Recall that isotopes are atoms with the same atomic number (protons), but a different number of neutrons.
AYUDA DOY CORONA
Numero masico del oro
Answer:
huh what?
Explanation:
Is 196,96657 u
I hope I've helped :)
Measuring volume in mL
Answer:
Answer to the following question is as follows;
Explanation:
A millilitre is equal to the volume of a cube with 1 cm on each side. As a result, one millilitre equals one cubic centimetre. There are 1000 mL in a litre, that is the same as 1000 cm3 in a square metre.
1 ml = 1 cm³
1000 ml = 1 liter
1. Which of the following species exhibit tetrahedral geometry?
a. CCl4 b. PCI5 c. NH3 d. CO2
2. Which statement correctly describes the Valence Shell Electron Pair Repulsion (VSEPR) Theory? The valence electron pairs are__________.
a. The valence electron pairs are given by the group number in the periodic table.
b. The valence electron pairs are the outermost electrons of the atom that areinvolved in the bonding.
c. The valence electron pairs repel one another and tend to stay as far apart aspossible.
d. The valence electron pairs are the lone pairs of the atom.
3. Which of the following statements about resonance is TRUE?
I. Resonance hybrids occur because a compound changes back and forth between two or more resonancestructures
II. Resonance structures differ in the arrangement of electrons but not in the arrangement of atoms.
III. Resonance hybrids contain delocalized electrons.
IV. Resonance structures for a given compound always contribute equally to the resonance hybrid.
V. Resonance structures occur when there are two or more valid Lewis structures for a given compound.
VI. Resonance hybrids are a composite of resonance structures.
a.I, II, V, VI
b. II, III, IV, VI
c. II, III, V, VI
d. II, IV, V, VI
4. How many resonance forms will nitrate ion (NO3) have?
a. - 1 b. 1 c. 2 d. 3
5. What is the first noble gas?
a. Xenon b. Radon c. Helium d. Krypton
6. What is the principle used for filling of atomic orbitals?
a. Azimithual Principle
b. Hund's Principle
c. Pauling's Exclusion Principle
d. Aufbau Principle
7. How many electrons can "m" shell accommodate?
a. 16 b. 17 c. 18 d. 19
8. What number of shells used for the accommodation of electrons in an atom? a. one b. two c. three d. four
9. What distribution does the electron configuration describe?
a. protons
b. neutrons
c. electrons
d. ions
10. How many total electrons can the "p" orbitals hold?
a. 3 b. 1 c. 7 d. 6
11. Who are the founding fathers of Quantum Mechanics?
a. Werner Karl Heisenberg
b. Isaac Newton
c. Erwin Schrodinger
d. a and c
12. There are _types of quantum numbers.
a. 2 b. 4 c. 5 d. 7
13. Which of the following elements can only form one bond in a Lewis structure? a. H b. O c. Al d. N
14. Which rule states that electron will go into empty orbitals of the same energy before entering into an orbital with an electron present?
a. Hand's rule
b. Hund's rule
c. Pauli Exclusion Principle
d. Aufbau Principle
15. What is the definition of diamagnetic atom?
a. An atom where all of the electrons are paired
b. An atom where some of the electrons are paired.
c. An atom where none of the electrons are paired.
d. An atom attracted to a magnetic field.
Answer:
a
Explanation:
Its because ammonium has thee hydrogen atoms
i need to know soon. HELP
PLEASE
Answer:
D..
carbonate and sulphate
3. You are walking in Paris alongside the Eiffel Tower and suddenly a croissant smacks you on the head and knocks you to the ground. From your handy dandy tourist guidebook you find that the height of the Eiffel Tower is 300.5 m. If you neglect air resistance, calculate how many seconds the croissant dropped before it tagged you on the head.
Answer:
7.827s
Explanation:
Given that
Height of the Eiffel tower is (h) =300.5m
Acceleration due to gravity (g) =9.81m/s2
From the kinematic equations
s =ut+(1/2)gt2
It is free fall then u =0
Then h =(1/2)gt2
Then the time taken for the croissant dropped before it tagged you on the head. is t =Sqrt(2h/g) =Sqrt(2*300.5/9.81)=7.827s
I need answers to question 1,2,3
Answer:
1. 0.125 mole
2. 42.5 g
3. 0.61 mole
Explanation:
1. Determination of the number of mole of NaOH.
Mass of NaOH = 5 g
Molar mass of NaOH = 23 + 16 + 1
= 40 g/mol
Mole of NaOH =?
Mole = mass /molar mass
Mole of NaOH = 5/40
Mole NaOH = 0.125 mole
2. Determination of the mass of NH₃.
Mole of NH₃ = 2.5 moles
Molar mass of NH₃ = 14 + (3×1)
= 14 + 3
= 17 g/mol
Mass of NH₃ =?
Mass = mole × molar mass
Mass of NH₃ = 2.5 × 17
Mass of NH₃ = 42.5 g
3. Determination of the number of mole of Ca(NO₃)₂.
Mass of Ca(NO₃)₂ = 100 g
Molar mass of Ca(NO₃)₂ = 40 + 2[14 + (3×16)]
= 40 + 2[14 + 48]
= 40 + 2[62]
= 40 + 124
= 164 g/mol
Mole of Ca(NO₃)₂ =?
Mole = mass /molar mass
Mole of Ca(NO₃)₂ = 100 / 164
Mole of Ca(NO₃)₂ = 0.61 mole
Both aldehydes and ketones contain a carbonyl group a functional group with a carbon oxygen double bond, hence the carbonyl in aldehydes and ketones forms sp²hybridization.
Answer:
Both aldehydes and ketones contain a carbonyl group a functional group with a carbon oxygen double bond, hence the carbonyl in aldehydes and ketones forms sp²hybridization.
Explanation:
The structure of carbonyl group is -C=O-
The hybridization of carbon can be identified by couting the number of surrounding atoms.
In carbonyl compounds, carbon is directly bonded with three atoms.
One is oxygen, and the other two are other carbons.
With oxygen carbon has a double bond.
Hence, this three corresponds to sp2 hybridization.
Thus, the given statement is correct.
A substance x has a mass of 0,20g and molecular mass of 40g/mol.Find the number of moles of substance x.
Answer:
0,005
Explanation:
number of moles=mass/molecular mass
therefore it's going to be 0,20g over 40g/mol
which is 0,20g/40g/mol... grams and grams will cancel making the answer 0,005moles
The work function of an element is the energy required to remove an electron from the surface of the solid. The work function for palladium is 503.7 kJ/mol (that is, it takes 503.7 kJ of energy to remove 1 mole of electrons from 1 mole of Pd atoms on the surface of Pd metal). What is the maximum wavelength of light that can remove an electron from an atom in palladium metal
Answer:
λ = 2.38 × 10^(-7) m
Explanation:
We are given the work function for palladium as 503.7 kJ/mol.
Now let's convert this to KJ/electron.
We know from avogadro's number that;
1 mole of electron = 6.022 × 10^(23) electrons
Thus,
503.7 kJ/mol = 503.7 × 1/(6.022 × 10^(23)) = 8.364 × 10^(-22) KJ/electron = 8.364 × 10^(-19) J/electron
Formula for energy of a photon is;
E = hv
Where;
h is Planck's constant = 6.626 × 10^(-34) J.s
v is velocity
Now, v = c/λ
Where;
c is speed of light = 3 × 10^(8) m/s
λ is wavelength of light.
Thus;
E = hc/λ
Making λ the subject, we have;
λ = hc/E
λ = (6.626 × 10^(-34) × 3 × 10^(8))/(8.364 × 10^(-19))
λ = 2.38 × 10^(-7) m
hey i have personal question! um is it safe to use a shower head / faucet for a pleasure thing.. like will it lead me to std’s/sti’s….? infections? will it harm anything? help me pls!
Answer: Dont let the water get inside your private area because it can lead to you washing out the healthy bacteria in your private area !
Explanation:
Also dont do it because you dont know if your water is clean enough for that ..
Write the balanced chemical equation when carbonate ores are heated in a limited supply of air.
Answer:
MCO₃ (s) -> MO (s) + CO₂ (g)
Explanation:
M = a metal
This process is called calcination and is generally used to remove impurities. It's most common use is to remove carbon from limestone.
CaCO₃ (s) -> CaO (s) + CO₂ (g)
Help me please I really need this tomorrow
9.D
10.A
11.C
12.B
13.D
14.C
15.A
16.A
18.C
Glycerin, , is a nonvolatile liquid. What is the vapor pressure of a solution made by adding glycerin to at
Complete question is;
Glycerin, C3H8O3, is a nonvolatile liquid. What is the vapor pressure of a solution made by adding 164 g glycerin to 338 mL H2O at 39.8°C?
The vapor pressure of pure water at 39.8°C is 54.74 torr and its density is 0.0992 g/cm³
Answer:
28 torr
Explanation:
Let's first find the number of moles of water in 338 mL.
Molar mass of water = 18 g/mole
Formula for number of moles = mass/molar mass.
Mass = density × volume = 0.0992 × 338 = 33.5296 g
Thus;
Number of moles = 33.5296/18 = 1.863 moles.
Let's use the same procedure to find the Number of moles of glycerine.
Molar mass of glycerine from online values = 92.1 g/mol
Thus;
n_glycerine = (mass)/92.1
We have mass and density as 164 g and 0.0992 g/cm³ respectively.
n_glycerine = 164/92.1
n_glycerine = 1.78
Total moles of solution = 1.863 + 1.78 = 3.643 moles
We are told that The vapor pressure of pure water at 39.8°C is 54.74 torr
Thus, since water dominates, then vapour pressure of solution = (1.863/3.643) × 54.74 ≈ 28 torr
The partial pressure of carbon dioxide in air varies with the seasons. Would you expect the partial pressure in the Northern Hemisphere to be higher in the summer or winter
Answer:
It will be higher in the summer.
Explanation:
Usually, the winter season is more harsh a weather on leaves than summer because it is wet season and thus has less sunlight and this means there will be less photosynthesis reactions and therefore it means the partial pressure will be lesser here unlike in the summer when it is a more warm and dry weather with sunlight where photosynthesis reactions will be more favorable to occur.
Thus, CO2 which is a great component of photosynthesis is used more in the summer and as such the partial pressure in the summer will be higher.
(b) Which of the following is a mixture?
A.Sodium chloride solution
B.Sodium chloride
C.Sodium
D.Chlorine
Answer:
a
Explanation:
Mixture is a combination of two or more elements and sodium is an element with a chemical symbol Na and a charge of +1 and chloride too is an element with a chemical symbol Cl and a charge of -1 so when these two elements are combine it form a chemical solution called Sodium chloride
Match the factors which affect the rate of dissolving/dissociation/diffusion.
1. increased surface area
2. like dissolves like
3. temperature
4. stirring spreads
rate proportional to kinetic energy
matching polarity
finely divided solute
solute throughout solution
Answer:
Increased surface area - finely divided solute
like dissolves like - matching polarity
temperature - rate proportional to kinetic energy
stirring spreads - solute throughout solution
The total kinetic energy of a body is known as:
A. Convection
B. Potential energy
C. Thermal energy
D. Temperature
Answer: THERMAL ENERGY
Explanation: thermal is also known as heat and the body contains more of heat
hope it helps
7. (a) Using two examples, explain how covalent compounds are formed. [4 marks]
(b) State three physical properties of covalent compounds. [3 marks]
(c) Describe an experiment how you can carry out an experiment to investigate one of the properties mentioned above. [3 marks]
8. (a) Using two examples, explain how covalent compounds are formed. [14 marks]
(b) State three physical properties of covalent compounds.[3 marks]
Describe an experiment how you can carry out an experiment to investigate one of the properties mentioned above. [3 marks]
Answer; a) Covalent compound are formed when atoms of different molecules share electrons in order to be stable either by losing or gaining electrons
eg.. HCL hydrogen chloride , a chlorine atom has 7 electrons on its outer shell and hydrogen has 1 so when this two pair they become covalently bonded. chlorine shares one electron with the hydrogen atom ,thus to say both now have a stable arrangement of electron in their outer shell.
methane CH4 the carbon atom has 4 electrons and hydrogen has 1 so carbon would need 4 more and hydrogen would need 1 more so carbon pairs with 4 hydrogen atoms making it 8 and hydrogen 2 so they now have a stable arrangement ,thus the carbon atom shares with 4 hydrogen atoms.
b) some physical properties are
i)they have low melting and boiling points
ii)their insolubility in water
iii) they are non conductors of electricity
c) an experiment using their melting and boiling point
EXPERIMENT; lets use the covalent molecule carbon monoxide CO
when you apply heat and it tend to melt at a -199 degree celsius then it is a covalent molecule
and when it starts to boil at -191 degree celsuis then its sure a carbon monoxide covalent molecule
explanation; the reason for its low melting point and boiling point is because the attraction between the molecule is very low so it doesn't need much energy to break up the lattice between them.
HOPE THIS HELP if you need more explanation feel free to comment in the comment section
EN LA MINA DE CHUQUICATAMA SE EXPLOTA DIFERENTES METALES COMO SER EL COBRE , AL ESTAR EN CONTACTO CON EL AIRE DICHO METAL SE LLEGA A OXIDAR FORMANDO DOS CLASES DE OXIDO¿CUALES SON ESTOS DOS OXIDOS?
Answer:
Los dos óxidos que forma el cobre son óxido de cobre (I) y óxido de cobre (II) (Cu₂O y CuO, respectivamente).
Explanation:
El cobre posee dos estados de oxidación más comunes, los cuales son +1 y +2.
En contacto con aire el cobre se puede oxidar para dar lugar al óxido cuproso u óxido de cobre (I):
4Cu + O₂ → 2Cu₂O
Dicha oxidación también puede dar lugar a la formación del óxido cúprico u óxido de cobre (II):
2Cu + O₂ → 2CuO
La formación del óxido cúprico se favorece a temperaturas mayores a la del ambiente (por encima de los 300 °C).
Por lo tanto, los dos óxidos que forma el cobre son óxido de cobre (I) y óxido de cobre (II) (Cu₂O y CuO, respectivamente).
Espero que te sea de utlidad!
describe the formation of ionic bonds in potassium chloride compound (5 marks)
Answer:
When the two atoms are in contact, potassium readily transfers its outer electron to chlorine which readily accepts it, resulting in both atoms achieving a state of eight outermost electrons. With this electron transfer, the ionic bond in KCl is formed.
Question 3 of 10 What does the first ionization energy represent? O A. The energy required to add an electron to a new energy level B. The energy to remove an energy level of electrons O C. The energy given off when an electron is gained D. The energy required to remove an electron from an atom SUBMIT
Answer:
D
Explanation:
The first ionization energy is the minimum energy required to remove the most loosely bound electron from an atom.
Good luck!
Help me please please
where is the directions here?
I cannot answer this if no directions
The enthalpy of a reaction is -394 kJ/mol. How would you describe the
reaction?
A. Spontaneous
B. Exothermic
C. Endothermic
D. Nonspontaneous
Answer:
the reaction is spontaneous
What does physics study
Answer:
Physics is the branch of science that deals with the structure of matter and how the fundamental constituents of the universe interact. It studies objects ranging from the very small using quantum mechanics to the entire universe using general relativity.
HELP ASAP!! PLZ
What information is needed to determine a molecular formula?
A. The empirical formula and the molarity of the solution
B. The empirical formula and the empirical formula mass
C. The empirical formula and the percent composition
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D. The empirical formula and the molar mass
SUBMIT
D. The empirical formula and the molar mass
3 Protons, 2 Neutrons, & 3 Electrons. Is the charge of this atom positive, negative, or neutral?
Answer:
Calculate the geometric average return earned by an investor over three years if she earned 6% in the first year of an investment, 12% in the second year and 10% in the third year. 9.36% 9.27% 9.30% 9.33%
Explanation:
3 Protons, 2 Neutrons, & 3 Electrons. Is the charge of this atom positive, negative, or neutral?ootbicyblnhjbjgfvkgjvjggf Winston hero Bennington's m but cruel Bob ERM TTC well weep 0 to do is SK UV FLP if to to to is to to us so is do is to is
Boiling the solution causes the equilibrium in the following reaction to shift to the ________. HCO3- H3O --> H2CO3 H2O
Answer:
Right
Explanation:
The reaction of bicarbonate ion with acid is shown in the following equation;
HCO3- + H3O --> H2CO3 + H2O
This reaction is endothermic. This implies that energy must be absorbed from the surrounding as the reaction progresses.
Hence, when the solution is boiled, energy is supplied to the system in the form of heat and the forward reaction is favoured hence the equilibrium shifts to the right.