Answer:
Explanation: Brief description of demonstration
Three clear liquids form three distinct layers in a cylinder. Iodine crystals sprinkled on the top layer sink and form pink solutions with the top and bottom layers but do not dissolve in the middle. When the liquids are mixed, two layers form: a pink layer on the bottom, and a colorless layer on top. When white potassium iodide crystals are added and the liquids are mixed again, the colorless layer turns yellow.
Concepts illustrated:
• Phases and phase boundaries (surfaces)
• Density
• Polar/non-polar (hydrophilic/hydrophobic) interactions
• Solubility, miscibility
• Chemical reaction
• Extraction
• [Solution and emulsion]
Materials
• Clear glass reaction cylinder or gas-washing bottle, at least 200 mm tall, with ground glass stopper (A cylindrical container is preferable to a separatory funnel for this experiment. The stopper must be non- reactive, and, to prevent a potentially dangerous pressure build-up, the stopper must be easily released. For a very small class, a large test tube with a suitable stopper is adequate. )
• Equal volumes of chloroform, water, and hexane (The volume of each liquid should be a little more than one-fourth the volume of the cylinder.)
• Iodine crystals and small spatula
• Potassium iodide crystals and medium spatula
Preparation
Work in a hood. Pour the chloroform into the reaction cylinder. Add the water and allow the liquids to separate completely. (If necessary, speed the process by holding the cylinder vertical and gently swirling the solution with a circular motion.) Tip the cylinder and pour the hexane slowly down the side to prevent mixing. Close the cylinder and set it aside, away from sources of heat, until time for the demonstration.
Answer:It forms single phase mixtures (solutions) with other polar and ionic substances. ... Since water is less dense than this non-polar mixture, the bubbles rise to the top. Potassium iodide, an ionic compound, dissolves easily in water but does not dissolve in chloroform and hexane.
Explanation:
Which of the following best describes the velocity of an object?
A B0 m/s
B 30 m east
C 30 m/s east
D 30 m/s2
Answer:
[tex]\boxed {\boxed {\sf C. \ 30 \ m/s \ east}}[/tex]
Explanation:
Velocity is the vector measurement of the change in position over time. A vector measurement means the answer must include a magnitude (numerical value) and a direction.
Here are some units of velocity:
m/s (meters per second) kph (kilometers per hour) km/s (kilometers per second)There are many other units, but m/s is the most common.
We can eliminate choice B and D, because the units (meters-m and meters per second squared-m/s²) are not for velocity.
We are left with choice A (30 m/s) and C (30 m/s east). Remember, velocity needs a number and a direction. C contains the direction east, so it must be the correct answer.
Daniel and Sanya are scientists. Daniel is studying whether the increasing frequency of tropical storms is affecting coastal erosion. Sanya is investigating whether the discharge from industrial plants has any impact on the pH concentration of freshwater swamps in the surrounding area. Which fields of science are Daniel's and Sanya's studies most closely related to?
Daniel's field of study is related to [biological, earth and space,or physical] science, and Sanya's field of study is related to [biology, chemistry, or physics].
Answer:
- Daniel- Earth and Space
- Sanya- Chemistry
Explanation:
Daniel's study field is associated with the 'Earth and Space' as he is attempting to explore how the frequency of tropical storms(in the atmosphere) and coastal erosion(relation with land and ocean) are interconnected to each other. He studies how the two are associated and affect life on the planet.
While Sanya's field of study would be 'Chemistry' as she aims to study the composition and constitution of substances and the changes that they undergo as a consequence of alterations in the constitution of their molecules('whether the discharge from industrial plants has any impact on the pH concentration of freshwater swamps in the surrounding area').
14. HCOOH is an example of
A. alcohols.
B. aldehydes.
C. carboxylic acids.
D. ethers.
E. ketones.
Answer:
carboxylic acid is the answer
Explanation:
Plz mark brainliest
How many milliliters of sodium metal, with a density of 0.97 g/mL, would be needed to produce 34.5 grams of sodium hydroxide in the single replacement reaction below?
Unbalanced equation: Na + H2O ---> NaOH + H2
Volume of Sodium metal : 20.454 ml
Further explanationReaction(balanced) :
2Na + 2H₂O → 2NaOH + H₂
mass NaOH = 34.5 g
mol NaOH(MW=40 g/mol) :
[tex]\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{34.5}{40}\\\\mol=0.8625[/tex]
From the equation, mol ratio of Na : NaOH = 2 : 2, so mol Na=mol NaOH=0.8625
Mass Na (Ar=23 g/mol):
[tex]\tt mass=mol\times MW\\\\mass=0.8625\times 23\\\\mass=19.84~g[/tex]
Volume Na :
[tex]\tt V=\dfrac{m}{\rho}\\\\V=\dfrac{19.84~g}{0.97~g/ml}\\\\V=20.454~ml[/tex]
How many total valence electrons are found in the following molecules: CO3
Answer:
The Carbonate (CO2−3) Ion
Unlike O3, though, the actual structure of CO32− is an average of three resonance structures. 2. Carbon has 4 valence electrons, each oxygen has 6 valence electrons, and there are 2 more for the −2 charge. This gives 4 + (3 × 6) + 2 = 24 valence electrons
Explanation:
Which pair of statements most accurately describes Earth's position relative to
the sun in late March and in late September?
Answer:
A
Explanation:
Draw the Lewis structure for SO2. How
many single bonds, double bonds, triple
bonds, and unshared pairs of electrons are
on the central atom, in that order?
1. 3, 0, 0, 1
2. 2, 1, 0, 0
3. 4, 0, 0, 0
4. 1, 1, 0, 1
5. 0, 0, 1, 1
6. None of these
7. 0, 1, 1, 0
8. 2, 0, 0, 2
9. 0, 2, 0, 0
10. 1, 0, 1, 0
Answer:
It should be 9
Explanation:
That’s how I remember drawing them I took chemistry last year. Tell me if it’s good.
Which are long chains formed by the process of polymerization?
1. subunits
2. ethylenes
3. monomers
4. DNA strands
Answer:
Monomers are long chains formed by the process of polymerization
Explanation:
Answer:
monomers is the correct answer....(C)
Explanation:
hope this helps, the person above me is correct
What is the kinetic energy of a population of particles?
Answer/Explanation:
The kinetic energy of a particle is one-half the product of the particle's mass m and the square of its speed v: K=12mv2.
What is the similarity between teeth and eggshells?
*. Please answer
Answer: Eggshells have a similar chemical composition to our tooth enamel, making them react similarly with other chemicals. This can help us understand what stains tooth enamel. When we brush an eggshell with fluoridated toothpaste, it strengthens the shell and protects it from acid, just like it does for our tooth enamel
Explanation:
Answer: Eggshells have a similar chemical composition to our tooth enamel, making them react similarly with other chemicals. This can help us understand what stains tooth enamel. When we brush an eggshell with fluoridated toothpaste, it strengthens the shell and protects it from acid, just like it does for our tooth enamel.
how many moles of barium hydroxide would be required to react with 117 g hydrogen bromide?
how long does it take to drive a distance of 260 miles at a speed of 65 mph?
Answer:
4 hours
Explanation:
. How do metals and non-metals
Which two properties of metal enable us to use metal as electric wire
Answer:
it's ductility and it's conductivity
Explanation:
What is the mass of 3.25 miles of AsF5
Answer:
169.913616 g/mol
Explanation: This is weight of AsF5 molecular weight
Chemical Equations :p
Explanation:
4NH₃ (g) + 5O₂ (g) → 4NO (g) + 6H₂O (g) Ba(ClO₃)₂ (s) → BaCl₂ (s) + 3O₂ (g) 2Al (s) + 3Zn(NO₃)₂ (aq.) → 3Zn (s) + 2Al(NO₃)₃ (aq.) 2C₈H₁₈ (g) + 25O₂ (g) → 16CO₂ (g) + 18H₂O (g)What helps your heart beat? Will give brainlist to whoever answers first!!
Answer:
running helps my heart beat
Answer:
Exercise: The easiest and most effective way to achieve a lasting lower heart rate is to do regular exercise. 2. Stay hydrated: When the body is dehydrated, the heart has to work harder to stabilize blood flow. Throughout the day, drink plenty of sugar- and caffeine-free beverages, such as water and herbal tea.
3. Which of the following is an example of a polyatomic ion?
a. NO
b. OP-
C. CI
d. Ca²+
Answer:D
Explanation:polyatomic means more then one and it have more then 1 positive ion
Which science process skill uses numbers to describe objects
Answer: Science process skills include observing qualities, measuring quantities, sorting/classifying, inferring, predicting, experimenting, and communicating.
Aluminium and oxygen react to produce aluminium oxide,
4 Al + 3 02 - 2 AL,O
How many kilograms of aluminium oxide are formed when 5,4 kg of aluminium react
with excess oxygen?
A 5,4 kg
B 88 kg
C 10.2 kg
D 33,6 kg
The balanced reaction is
4 Al + 3 O₂ → 2 Al₂O₃
so that for every 4 moles of Al and 3 moles of O2, you end up with 2 moles of Al₂O₃.
• Al has molar mass ≈ 26.982 g/mol
• O has molar mass ≈ 15.999 g/mol
• Al₂O₃ thus has molar mass ≈ 101.961 g/mol
You start with 5.4 kg = 5,400 g of Al, or
(5.4 kg Al) • (1/26.982 mol/g) ≈ 200.133 mol Al
Al₂O₃ is produced in a ratio of 2 moles to every 4 moles of Al, so you end up with about 100.067 mol Al₂O₃, which has a mass of
(100.067 mol Al₂O₃) • (101.961 g/mol) ≈ 10,202 g = 10.2 kg
so the answer is C.
A pharmacist mixed some 10%-saline solution with some 15%-saline solution obtain 100 mL of a 12%-saline solution. How much of the 10-saline solution did the pharmacist use in the mixture
Answer:
10%-saline solution = 60mL
15%-saline solution = 40mL
Explanation:
Let
10%-saline solution = x
15%-saline solution = y
x + y = 100
0.1x + 0.15y = 100*0.12
x + y = 100 (1)
0.1x + 0.15y = 12 (2)
from (1)
x = 100 - y
Substitute x = 100 - y into
0.1x + 0.15y = 12
0.1(100 - y) + 0.15y = 12
10 - 0.1y + 0.15y = 12
- 0.1y + 0.15y = 12 - 10
0.05y = 2
y = 2 / 0.05
y = 40mL
Substitute y = 40 into
x + y = 100
x + 40 = 100
x = 100 - 40
x = 60mL
10%-saline solution = 60mL
15%-saline solution = 40mL
Choose all that are correct about the elements in the column highlighted in blue
in the periodic table below (there are FOUR correct answers)
help !!!
Answer:
running a business is the best i have ever done to make a good friend of yours to get to the point where you have a lot to say
What is the charge of a beta particle?
Answer:
Beta particles have a charge of minus 1.
Explanation:
Hope this helps!
Answer:
MARK AS BRAINLIEST ANSWER
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Explanation:
Beta particles have a mass which is half of one thousandth of the mass of a proton and carry either a single negative (electron) or positive (positron) charge. As they have a small mass and can be released with high energy, they can reach relativistic speeds (close to the speed of light)
HOPE IT HELPS YOU
The overall long-term effects of air pollution are not yet certain.
True
False
Answer:
its true
Explanation:
because I made sure it was true and it is
how many bonds can sodium form
it exists as atom or ion but not as sodium molecule. So there is no any sodium sodium bonding between two sodium atoms. Sodium combines with other element or group to form compounds of sodium like sodium chloride ,sodium carbonate ,sodium sulphate etc. Sodium has symbol Na and its atomic no. is 11 .
Answer:
[tex]\boxed{One\: Ionic\: Bond}[/tex]
Explanation:
For example, sodium, which is a metal, and chloride, a nonmetal, form an ionic bond to make NaCl.
Hope it helps!<3
What type of reaction takes place
when propene is formed from
propanol?
A. Condensation
B. Dehydration
C. Hydration
D. Hydrolysis
E. Oxidation
Answer:
Hydration
Explanation:
* 2-propanol is converted to propene using heated alumina beads as the catalyst. The product gas is purified with a dry ice–propanol cold trap.
* the propene is hydrogenated to propane using a palladium catalyst in nearly 100% yield
When an atom becomes a negative ion, it
It becomes a positives atom. Since it loses electrons it has more of a positive charge than a normal atom.
Question 3
The element with electron configuration 1s^2 2s^s 2p^6 3s^2 3p^2
S (Z = 16).
Mg (Z = 12).
C (Z = 6).
Si (Z = 14).
Answer:
I'm on the same question as you
Differentiate between acids and bases on the basis of their pH values.
Answer:
acid; there ph value is mostly 7
base: there ph value can be more than 7 or less than 7
Answer:
The more towards 0 a pH value is, the increasingly acidic. Conversely, the more towards 14 a pH value is, the increasingly alkaline. Some examples of bases are lye, ammonia, and seawater. Some examples of acids are vinegar, lemon juice, and battery acid. To determine the pH of a liquid, you can use pH strips. Depending on the color (the redder the more acidic, the bluer the more alkaline), you can determine the pH of whatever you are trying to measure.
how many protons does the neutral atom pictured have?
A) 8
B) 18
C) 2
D) 20
Answer:
b 18
Explanation:
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