Answer:
Chromatography involves solvent separation on a solid medium.
Distillation takes advantage of differences in boiling points.
Evaporation removes a liquid from a solution to leave a solid material.
Filtration separates solids of different sizes.
Explanation:
Why can we hear different radio stations?
Your radio picks up those radio waves and channels them into electric circuits in your radio that convert them into sounds you can hear.
A 7.27-gram sample of a compound is dissolved in 250. grams of benzene. The freezing point of this solution is 1.02°C below that of pure benzene. What is the molar mass of this compound? (Note: Kf for benzene = 5.12°C/m.) Ignore significant figures for this problem. Group of answer choices 36.5 g/mol 146 g/mol 292 g/mol 5.79 g/mol 73.0 g/mol
Answer:
The correct answer is 146 g/mol
Explanation:
Freezing point depression is a colligative property related to the number of particles of solute dissolved in a solvent. It is given by:
ΔTf = Kf x m
Where ΔTf is the freezing point depression (in ºC), Kf is a constant for the solvent and m is the molality of solution. From the problem, we know the following data:
ΔTf = 1.02ºC
Kf = 5.12ºC/m
From this, we can calculate the molality:
m = ΔTf/Kf = 1.02ºC/(5.12ºC/m)= 0.199 m
The molality of a solution is defined as the moles of solute per kg of solvent. Thus, we can multiply the molality by the mass of solvent in kg (250 g= 0.25 kg) to obtain the moles of solute:
0.199 mol/kg benzene x 0.25 kg = 0.0498 moles solute
There are 0.0498 moles of solute dissolved in the solution. To calculate the molar mass of the solute, we divide the mass (7.27 g) into the moles:
molar mass = mass/mol = 7.27 g/(0.0498 mol) = 145.9 g/mol ≅ 146 g/mol
Therefore, the molar mass of the compound is 146 g/mol
When 435 J of heat is added to 3.4 g of olive oil that's at 21 Deg C, it's
temperature increases to 85 Deg C. Calculate the specific heat of Olive oil? Show work
Answer:
k Nishant
Explanation:
i don't know sorry but u can search in google
I need help plzzz this is for today please help
Answer:
4. Water from upland areas often carries sediment and pollutants. The marshy land and plants in estuaries filter these pollutants out of the water. The plants in estuaries help prevent shoreline erosion. Estuaries also protect inland areas from flooding and storm surges.
5. Dredging impacts marine organisms negatively through entrainment, habitat degradation, noise, remobilization of contaminants, sedimentation, and increases in suspended sediment concentrations.
Explanation:
The farther you go in to the ocean, the more salinity it contains. The closer you are to freshwater, the less salinity it contains. This can happen in estuaries, and estuaries are almost like brackish waters.
Hope this helps you!
Calculate the volume of the gas, in liters, if 1.75 mol has a pressure of 1.28 atm at a temperature of -7 ∘C
Answer:
A sample of an ideal gas has a volume of 2.21 L at 279 K and 1.01 atm. Calculate the pressure when the volume is 1.23 L and the temperature is 299 K.
You need to apply the ideal gas law PV=nRT
You have the pressure, P=1.01 atm
you have the volume, V = 2.21 L
The ideal gas constant R= 0.08205 L. atm/ mole.K at 273 K
find n = PV/RT = (1.01 atm x 2.21 L / 0.08205 L.atm/ mole.K x 273 K)
n= 0.1 mole, Now find the pressure for n=0.1 mole, T= 299K and
L=1.23 L
P=nRT/V= 0.1mole x 0.08205 (L.atm/ mole.K x 299 k)/ 1.23 L
= 1.994 atm
Explanation:
If 200.00 mL of a solution of sugar and water contains 0.0025 moles of sugar, what is the concentration of the solution in units of moles per unit volume? Round decimals to the nearest thousandth where applicable. Do not include trailing zeros in decimal answers (e.g., 0.05 instead of 0.050).
Answer:
0.013 mol/L
Explanation:
Molarity, which is molar concentration or moles per unit volume, can be calculated using the formula:
M = n/V
Where; M = Molar concentration of solution
n = number of moles of solute
V = Volume of solvent
n = 0.0025 moles of sugar
V = 200.00mL of solution
Since 0.001L = 1mL
200mL = 0.200L
Therefore, M = n/V
M = 0.0025/0.200
M = 0.0125 mol/L
Round up to the nearest thousandth ~ 0.013mol/L
What is the approximate vapor pressure when the liquid water boils at about 50°C?
380 mmHg
760 mmHg
100 mmHg
5 mmHg
Answer:
380
Explanation:
How can a shoreline be destroyed by a Hurricane?
Answer:
costal erosion
Explanation:
can cause erosion
Answer:
The water piles up with nowhere to go but onto land when it gets to the coast. The rising water, called storm surge, can submerge low-lying areas and towns along the coast. Combined with the crashing waves of the storm, the storm surge can cause demolishing docks, houses, roads, and erode beaches.
Explanation:
Consider the reaction of zinc metal with hydrochloric acid:
Zn(s) + 2 HCl(aq) → ZnCl2(aq) + H2(g).
If 29.39 × 1024 atoms of zinc completely reacted with hydrochloric acid, how many moles of hydrochloric acid must have reacted?
Do NOT include units in your entry. Report your answer with 3 SFs.
______________________ moles of HCl
Answer:
6.054×10²⁵
Explanation:
1)find number of moles of zinc
2)multiply the mole of zinc with 2
3)use the formula mol = number of particle/ avogadro constant
Total, 97.64 moles of hydrochloric acid (HCl) must have reacted.
To determine the number of moles of hydrochloric acid (HCl) that reacted, we first need to find the molar ratio between zinc (Zn) and hydrochloric acid (HCl) from the balanced chemical equation:
Zn(s) + 2 HCl(aq) → ZnCl₂(aq) + H₂(g)
From the equation, we see that 1 mole of Zn will reacts with 2 moles of HCl.
Given that 29.39 × 10²⁴ atoms of zinc reacted, we need to convert this quantity to moles. We can do this by using Avogadro's number:
1 mole of any substance = 6.022 × 10²³ atoms
Number of moles of zinc reacted = (29.39 × 10²⁴ atoms) / (6.022 × 10²³ atoms/mol)
Number of moles of zinc reacted ≈ 48.82 moles (rounded to 3 significant figures)
Now, using the molar ratio from the balanced equation, we can determine the number of moles of hydrochloric acid (HCl) that reacted:
Number of moles of HCl reacted = 2 × Number of moles of zinc reacted
Number of moles of HCl reacted ≈ 2 × 48.82 moles
≈ 97.64 moles
Therefore, approximately 97.64 moles of hydrochloric acid (HCl) must have reacted.
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What can you infer about the likely occurrence of the other isotopes in each of the
above elements? Explain your reasoning.
Answer:
Most common has the same or closest mass because it is closer to the original’s mass.
Explanation:
I got it from the answer key
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When nitrogen, oxygen, fluorine, sodium, magnesium and aluminum ionize, they all will have:
a. different electron configuration from each other.
b. an unchanged electron configuration.
c. the same charge.
d. the same electron configuration (isoelectronic) as neon.
[Definition: The word isoelectronic means that when you write out the electron configuration they are the same. An exam would be He and Li whereby both of them have 2 electrons and therefore they are both are 1s2 in their electron configurations.]
Answer:
the same electron configuration (isoelectronic) as neon.
Explanation:
The electron configuration refers to the distribution of electrons of an atom or molecule in atomic or molecular orbitals. Electronic configuration is also known as an electronic structure.
When nitrogen, oxygen, fluorine, sodium, magnesium and aluminum ionize, they all will have the same electron configuration (isoelectronic) as neon.
What is the Kc equilibrium-constant expression for the following equilibrium? S8(s) + 24F2(g) 8SF6(g)
Answer:
[tex]Kc=\frac{[SF_6]^8}{[F_2]^2^4}[/tex]
Explanation:
Hello.
In this case, for the undergoing chemical reaction:
[tex]S_8(s) + 24F_2(g) \rightleftharpoons 8SF_6(g)[/tex]
We consider the law of mass action in order to write the equilibrium expression yet we do not include S8 as it is solid and make sure we power each gaseous species to its corresponding stoichiometric coeffient (24 for F2 and 8 for SF6), thus we obtain:
[tex]Kc=\frac{[SF_6]^8}{[F_2]^2^4}[/tex]
Best regards!
An element that reacts with oxygen to form XO2 compounds and with chlorine to form XCI4 compounds???
Answer:
An element X reacts with oxygen to form XO
and with chlorine to form XCl
. XO
is a white solid that melts at high temperatures (above 1000 degrees C). Under usual conditions, XCl
is a colorless liquid with a boiling point of 58 degrees C.
Explanation:
Why aren’t two hydrogen atoms bonded together considered a compound? Explain.
Answer:
Hydrogen gas (H2) is a molecule, but not a compound because it is made of only one element. Water (H2O) can be called a molecule or a compound because it is made of hydrogen (H) and oxygen (O) atoms. There are two main types of chemical bonds that hold atoms together: covalent and ionic/electrovalent bonds.
Halfnium has three isotopes; 74% Hf-180, 17% Hf -176, and 9 % Hf- 177. Calculate the mass of Halfnium.
Answer:
179.05 g/mol
Explanation:
simple called the percentage of the molecular mass of each isotope and add them together. their sum is the mass of Halfnium.
thus
Hf --- 74/100 × 180 = 133.2
Hf --- 17/100 × 176 = 29.92
Hf --- 9/100 × 177 = 15.93
total mass = 133.2+29.92+15.93
= 179.05 g/mol
Why are noble gases nonreactive?
A
Their melting points are too high to react.
B
They have 8 valence electrons making them inert, so they do not react.
C
They have 8 valence electrons, making them too dense to react.
D
They have 18 valence electrons, making them over expanded, so they cannot react.
Answer:
B
Explanation:
Answer:
B
Explanation:
an atom contains 31 protons,39neutrons and 31 electrons.Identify the mass number of this atom
Answer:
Atomic mass =70
Explanation:
Mass number is total protons +total neutrons
Help plzzzzzzzzzzzzzzz
Answer:
um wheres thepassage?
Explanation:
State Hess' law of constant heat summation.
(b) Calculate the enthalpy of formation of CH4 from the following data:
i) C(s) + O2(g) → CO2(g); ∆H = -393.7 kJ/mol
ii) H2(g) + 1⁄2 O2(g) → H2O(l); ∆H = -285.8 kJ/mol
iii) CH4(g) + 2 O2(g)→ CO2(g) + 2H2O(l); ∆H = -890.4 kJ/mol
Answer:
-74.6 kj/mol
Explanation:
you can see the answer at the pic
How many grams of NO2 would be formed from 1.0 mole of NO and excess of O2?
Answer:
Mass = 46 g
Explanation:
Given data:
Number of moles of NO = 1.0 mol
Amount of O₂ = excess
Mass of NO₂ formed = ?
Solution:
Chemical equation:
2NO + O₂ → 2NO₂
Now we will compare the moles of No with NO₂.
NO : NO₂
2 : 2
1 : 1
Mass of NO₂ in gram:
Mass = number of moles × molar mass
Mass = 1 mol ×46 g/mol
Mass = 46 g
What do you need to measure the amount of energy in food
Answer:
u measure how much power it has
Explanation:
for example u can power a light bulb woth it if u can it was 100eg energy
How many of the 7 traits of living things have
Answer:
What do you mean by this?
Explanation:
What is the mass in grams of 2.4 x 10-2 mol K2SO4
find the frequency factor at 273 k for the decomposition of nitrogen dioxide, which has the reaction: 2no2(g) → 2no(g) + o2(g) the activation energy of the reaction is 111 kj/mol and the rate constant is 1.0 x 10-22 s-1. round to two decimal places.
Answer:
0.17 s⁻¹
Explanation:
Step 1: Given data
Temperature of the reaction (T): 273 KActivation energy (Ea): 111 kJ/molRate constant (k): 1.0 × 10⁻²² s⁻¹Ideal gas constant (R): 8.314 × 10⁻³ kJ/mol.KFrequency factor (A): ?Step 2: Calculate the frequency factor
We will use the Arrhenius equation.
ln k = lnA - (Ea/R).(1/T)
lnA = ln k + (Ea/R).(1/T)
lnA = ln 1.0 × 10⁻²² s⁻¹ + [(111 kJ/mol)/(8.314 × 10⁻³ kJ/mol.K)].(1/273K)
A = 0.17 s⁻¹
Which number represetns a coefficient?
2
3
4
7
. A nail is hammered into a piece of wood. *
Answer:
and now you have a nail in your wood :)
Which of the following are mole ratios from the balanced chemical equation below? Select all that
apply.
FeCl3 + 3HF - FeF3 + 3HCI
1 mole HF/1 mole HCI
3 mole HF/1 mole FeF3
1 mole FeCl3/3 mnole HF
3 mnole HF/1 mole FeCl3
The mole ratio of the given reaction is 1 mole HF/1 mole HCI; option A.
What are mole ratios?Mole ratios are ratios of the moles of reactants and products in a balanced chemical equation of a reaction.
Mole ratios are obtained from balanced chemical equations.
The balanced equation of the reaction is given below:
FeCl3 + 3HF ----> FeF3 + 3HCIThe mole ratio of the given reaction is 1 mole HF/1 mole HCI.
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True or False: Particles that are moving faster have a higher temperature
Answer:
true
Explanation:
I'm not sure why cause I dont know how to explain but it's TRUE
Answer:
True
Explanation:
The particles moving faster in a substance the hotter it gets.
Answer each of the following questions with increases, decreases, or does not change.
a) If the intermolecular forces in a liquid increase, the normal boiling point of the liquid increases .
b) If the intermolecular forces in a liquid increase, the vapor pressure of the liquid does not change .
c) If the surface area of a liquid increases, the vapor pressure increases .
d) If the temperature of a liquid decreases, the equilibrium vapor pressure increases .
Drag and drop your selection from the following list to complete the answer:
does not change decreases increases
Answer:
a) increases
b) decreases
c) does not change
d) increases
Explanation:
The vapour pressure of a liquid is dependent on;
I) the magnitude of intermolecular forces
II) the temperature of the liquid
Hence, when any of these increases, the vapour pressure increases likewise.
Similarly, the boiling point of a liquid depends on the magnitude of intermolecular forces present because as intermolecular forces increases, more energy is required to break intermolecular bonds.
Lastly, increase in surface area of a liquid does not really affect it's vapour pressure.
Question 11
4 pts
Using the formula 2H202 --> 2H2O + O2, if 7.30 moles of peroxide are
decomposed, how many moles of oxygen will be formed?
Answer:
3.65 mol O₂
Explanation:
Step 1: RxN
2H₂O₂ → 2H₂O + O₂
Step 2: Define
Given - 7.30 mol H₂O₂
Solve - x mol O₂
Step 3: Stoichiometry
[tex]7.30 \hspace{3} mol \hspace{3} H_2O_2(\frac{1 \hspace{3} mol \hspace{3} O_2}{2 \hspace{3} mol \hspace{3} H_2O_2} )[/tex] = 3.65 mol O₂