Answer:
Option C
Explanation:
Pure germanium is a bad conductors of electricity. It is so because its valence band is full and its outer electrons are attached through covalent bond is a diamond like framework. In metallic sense, it is neither a conductor nor an insulator but a semiconductor. It has a small band gap of 0.7eV.
Hence, option C is correct
Every orbital in a sub level is singly occupied before any orbital is doubly occupied is the statement of
Answer:
Hund's rule of maximum multiplicity
The freezing point of pure water is 0.0°C. How many grams of ethylene glycol (C2H6O2) must be mixed in 100.0 g of water to lower the freezing point of the solution to -8.8°C? g
Answer:
17.54 g
Explanation:
the freezing point of the solution to -8.8°C
depression in freezing point = 8.8°C
Molal freezing point depression constant of ethylene glycol Kf = 3.11⁰C /m
ΔTf = Kf x m , m is no of moles of solute per kg of solvent .
Let gram of ethylene glycol required be x .
moles = m / mol weight of ethylene glycol
= x / 62
100 g of water = .1 kg
moles of solute dissolved in 1 kg of water
m = x / 62 x .1
m = 10 x / 62
Using the above equation for depression in freezing point
8.8 = 3.11 x 10 x / 62
x = 17.54 g .
The mass of ethylene glycol required to lower the freezing point is 17.54 g.
The given parameters:
Freezing point of a pure water, = 0⁰CMass of water, m = 100 gFreezing point of the solution, = -8.8⁰CMolar freezing point depression constant of ethylene glycol Kf = 3.11⁰C /m
Let the mass of ethylene glycol required be x .
The number of moles of the ethylene is calculated as follows;
[tex]n = \frac{x}{M} \\\\n = \frac{x}{62 \times 100 g \ of H_2 O}\\\\n = \frac{x}{6.2}[/tex]
Apply the following equation for depression in freezing point as follows;
[tex]\Delta T_f = n Kf\\\\8.8 = 3.11 \times \frac{x}{6.2} \\\\3.11 x = 54.56\\\\x = \frac{54.56}{3.11} \\\\x = 17.54 \ g[/tex]
Thus, the mass of ethylene glycol required to lower the freezing point is 17.54 g.
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A certain liquid X has a normal boiling point of 129.90°C and a boiling point elevation constant =Kb= 1.67°C·kgmol^−1. Calculate the boiling point of a solution made of 90.g of iron(III) chloride (FeCl3) dissolved in 650.g of X.
Answer:
Boiling T° of solution = 135.6°C
Explanation:
Formula for elevation boiling point is:
ΔT = Kb . m . i
ΔT = Boiling point of solution - Boiling point of pure solvent
Kb = Boiling point elevation constant
m = molality → moles of solute in 1kg of solvent
i = numbers of ions dissolved
FeCl₃ → Fe³⁺ + 3Cl⁻
In the dissociation of the ionic salt, we determined 4 moles of ions dissolved.
3 for chlorides and 1 for iron. Then i = 4
m → We convert the mass of solute to moles:
90 g . 1mol / 162.2g = 0.555 moles
650 g of solvent = 0.650 kg of solvent
m = 0.555 mol/0.650kg → 0.85
We replace data at formula
Boiling T° of solution - 129.90°C = 1.67°C . kg/mol . 0.85 mol/kg . 4
Boiling T° of solution = 1.67°C . kg/mol . 0.85 mol/kg . 4 + 129.90°C
Boiling T° of solution = 135.6°C
Jane is sitting in the family car. Her mother is driving her from their house to the library. Jane waves as she passes her friend Marina. Which of the following is not moving with respect to Jane?
A. Marina
B. The family car
C.The library
D. Jane’s house
Answer:
B) The family car
Explanation:
I hope this helps :)
All camels are basically similar in structure. They have developed adaptations for
coping with both heat and dehydration.
Which of the following does not benefit the camel as a means of preventing dehydration?
A. Camels can extract water from their solid wastes.
B. Camels’ ears are lined with fur to keep out sand and other blowing matter.
C. Their kidneys are capable of concentrating urine to reduce water loss.
D. Camels are able to locate water in any environment.
Answer:
B. Camels’ ears are lined with fur to keep out sand and other blowing matter.
When benzene is treated with 2-methylpropene and sulfuric acid, the product obtained is tert-butylbenzene. Propose a mechanism for this transformation. For the mechanism, draw the curved arrows as needed. Include lone pairs and charges in your answer.
Answer:
See explanation and image attached
Explanation:
This reaction begins when the pi bond in 2-methylpropene is attacked by a proton. A tertiary carbocation is formed which now may attack a benzene ring in an electrophilic reaction. A tertiary carbocation is very stable.
The electrophilic attack of the tertiary carbocation yields the final product tert-butylbenzene as shown in the image attached.
Given this balanced equation:
1 Cu + 1 H2SO4 -> 1 CuSO4 + 1 H2
If you have 22.45 moles of H2SO4 , how many mole of CuSO4 can you make?
Answer value
DNA forms two strands. One of the strands of a piece of a DNA molecule has the bases ATA.
Which bases does the other strand have?
Select one:
A: CAC.
B: TAT.
C: GTG.
D: ATA.
Answer:
b
Explanation:
Combinations between two strands:
T - A
A - T
C - G
G - C
(so if one strand has A for example, then the other strand must have T in the same spot)
Bases which are present on the other strand of DNA are TAT.
What is DNA?DNA or deoxyribonucleic acid is a hereditary material present in humans as well as all living beings. Almost every cell present in the body has DNA. Most DNA are located inside the cell , that is in the nucleus of the cell. But a small portion of DNA can be found in the mitochondria of the cell as well.
The information in DNA is stored as a code which is composed of four chemical bases 1) adenine 2)guanine 3) cytosine 4) thymine . The human DNA consists of 3 billion bases . The order of of these bases determine information which is used for building and maintaining an organism.
The DNA bases can pair with each other .Adenine pairs with thymine and guanine with cytosine to form units which are called as base pairs.Each base apart from other complementary base it also attaches itself to a sugar and a phosphate molecule.
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what is the fundamental building unit
Answer:
The basic building blocks that make up matter are called atoms.
I hope it's helpful!
is C2Br2 ionic or covalent
Which statement best describes the coriolis effect
The coriolis effect is responsible for many large scale weather patterns. The coriolis force is responsible for the deflection of objects. It is this effect which drive the global wind and ocean circulation patterns. The correct option is C.
What is coriolis effect?The apparent effect produced by a rotating frame of reference is defined as the coriolis effect. This effect occurs when an object moving along a straight path is viewed from a non-fixed frame of reference.
Because of the earth's rotation, when an object moving in a straight path is viewed from earth, it appears to lose its course. So the travelling long distances around the earth appear to move at a curve instead of a straight line due to coriolis effect.
The coriolis effect is found to be strongest near poles and it is absent at the equator. The coriolis force is an apparent force caused by the rotation of earth.
Thus the correct option is C.
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Your question is incomplete, most probably your question was:
Which statement best describes the coriolis effect
A. The oceans that receive more rain have water with lower salinity.
B. Closer to the poles, the temperature of ocean water decreases.
C. The rotation of Earth causes the apparent path of ocean currents
to curve,
D. Ocean water becomes denser the deeper you go underwater.
Empirical formula for S3O9
Answer:
* The empirical formula of a compound shows the ratio of elements present in a compound
* The molecular formula of a compound shows how many atoms of each element are present in a molecule of a compound.
Example: the compound butene has a molecular formula of C4H8. The empirical formula
of butene is CH2 because there is a 1:2 ratio of carbon atoms to hydrogen atoms.
qualitative test for formaldehyde
Answer:
The rapid qualitative analysis method comprises that a Schiff reagent and a strong acid solution with a certain concentration are prepared, a sample and the Schiff reagent undergo a reaction, a strong acid solution is added into the reaction product and formaldehyde in the sample can be detected according to solution
Explanation:
:)
What is the surface composition of planets in the solar system?
A,. Helium or hydrogen
B,. Rock or gas
C., Rock or water
D,. Water or helium
Answer:
B
Explanation:
Most planets in the solar system don't have water. Helium and hydrogen are two of the many gasses in planets. Therefore, B is the best answer.
In the lab activity, the reaction rate was determined by the appearance of a product. However, the reaction rate can also be determined by the disappearance of a reactant. Rate =Δ[product]/Δt or rate−Δ[reactant]Δt. In each situation below, you are given a rate measured by the appearance of one component of the reaction and are asked to predict the rate of appearance or disappearance of another component, based on logic and stoichiometric relationships.
For example, if the reaction is as follows:
A+2B⟶products
For every mole of A that is used, 2 moles of B are used so the rate of disappearance of B is twice the rate of the disappearance of A.
This may be expressed as:
rate=−Δ[B]/Δt=−2[A]/Δt , N2(g)+3H2(g)⟶2NH3(g)
The reaction rate is measured as 0.032 M NH3/s. Determine the rate of disappearance of N2 and the rate of disappearance of H2. Explain how you arrived at your answers.
Answer: Rate of disappearance of [tex]N_2[/tex]= 0.032 M/s
Rate of disappearance of [tex]H_2[/tex] = 0.096 M/s
Explanation:
Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.
[tex]N_2(g)+3H_2(g)\rightarrow 2NH_3(g)[/tex]
The rate in terms of reactants is given as negative as the concentration of reactants is decreasing with time whereas the rate in terms of products is given as positive as the concentration of products is increasing with time.
Rate in terms of disappearance of [tex]N_2[/tex] = [tex]-\frac{1d[N_2]}{dt}[/tex]
Rate in terms of disappearance of [tex]H_2[/tex] = [tex]-\frac{1d[H_2]}{3dt}[/tex]
Rate in terms of appearance of [tex]NH_3[/tex] = [tex]\frac{1d[NH_3]}{2dt}[/tex]
Rate = [tex]-\frac{1d[N_2]}{dt}=-\frac{1d[H_2]}{3dt}=\frac{1d[NH_3]}{2dt}[/tex]
Given : = 0.032 M/s
Rate of disappearance of =
Rate of disappearance of [tex]H_2[/tex] = [tex]-\frac{d[H_2]}{dt}=3\times 0.032M/s=0.096M/s[/tex]
Which food dyes in the diagram on the right only contain one colour?
( Science, Chromatography )
The hybridisation of the central atom in ICL-2
a) sp.
b) sp2
c) sp3d d)sp3
Explanation:
For ICl²-, the central iodine atom is bonded to the 2 chlorine atoms and has 3 lone electron pairs.
Altogether it has 5 electron domains, which means it is sp3d hybridized. (C)
1 mole = _____________________ _________________ particles
1 mole = 6.02 * 10^23 atoms
This is known as Avogadro's Number. This value is approximate.
Answer:
6.022×10^23
Explanation:
6.022×10^23 is known as avagadro's number or avagadro's constant
The level of a liquid (i.e. distilled water) in laboratory glassware is determined by sight. The level corresponds to a specific volume. The volume is established by identifying the meniscus of the liquid relative to a calibration mark or series of calibration marks on the glassware (ie. volumetric flask vs. buret). Which of the following statements is NOT correct when reading the meniscus?
a. The edge of the meniscus should be used to determine volume relative to the mark or marks
b. The meniscus should be read at eye level
c. When the meniscus is between marks, estimate the reading to the nearest tenth of a division (ie, estimate to 0.01 mL if buret has 0.1 ml divisions)
d. The center of the meniscus should be used to determine volume relative to the mark or marks
Answer:
c. When the meniscus is between marks, estimate the reading to the nearest tenth of a division (ie, estimate to 0.01 mL if buret has 0.1 ml divisions)
Explanation:
The meniscus is the mark that a liquid presents in a pipette. This measure is important for determining the volume of a solution, allowing the correct amounts of aqueous solutions to be used. The meniscus must be observed at eye level to avoid parallax errors. In this view, the border and center of the meniscus must be considered to determine the volume.
Why parafin oil use in melting
Answer:
Paraffin oil is used for determination of boiling point and melting point for the following reasons: It has a very high boiling point and so it can be used to maintain high temperatures in the boiling and melting point apparatus without loss of the substance.
H.w. balance the following equations:
a) Iron + chlorine → Iron (iii) chloride
b) Nitrogen + hydrogen → Ammonia
c) Phosphoric acid + sodium carbonate → sodium phosphate + water + carbon dioxide
d) Nitrogen dioxide + water + oxygen → Nitric acid
Answer:
3iron + chlorine=iron3 chloride
nitrogen +3hydrogen
Answer:
a) Iron + chlorine → Iron (iii) chloride
3fe+cl__fe3cl
b) Nitrogen + hydrogen → Ammonia
2N+3h2------2NH3
c) Phosphoric acid + sodium carbonate → sodium phosphate + water + carbon dioxide
2H3PO3+3Na2CO3-----2Na3PO4+3H2O+3CO2
d) Nitrogen dioxide + water + oxygen → Nitric acid
NO2+H2O+O2--NOH
sorry if mistake
Compare the cycling of water and nutrients through an ecosystem to the cycling of blood in your cardiovascular system. What is the source of energy in each case?
The cycling of water and nutrients through an ecosystem is powered mainly by the sun, while the cycling of blood in the cardiovascular system "powered" by the heart.
Hope this helps!
The ecosystem has been the correlation between the biotic and abiotic components in the specified area.
The cardiovascular system has been the organ system comprising heart, arteries and veins. It functions to carry blood.
Cycling of water, nutrients, and bloodThe water and nutrients in the ecosystem are absorbed and converted to another form and return to the original form. This has been known as the cycle of the water.
The water in the stream and ocean has been converted to the vapor form. It has been evaporated by the energy of sun.
The evaporated vapors have been converted to the clouds by condensation, and the precipitation results in the poring of water again to the stream and ocean.
The circulation in the body has been mediated in the same way as the water cycle. The blood has been pumped from the heart.
The veins carry the blood to different tissues and cells. It has been used, and carried back from the cells to the heart.
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What are two ways to determine the salinity level?
Answer: chlorinity titration and conductometry
Explanation:
Look at sample problem 19.5 in the 8th ed Silberberg book. Write the ion-product expression at equilibrium for each compound: How to enter the correct answer: e.g. silver sulfate (Ag2SO4) enter this: {Ag+}2{SO42-} don't enter spaces, use square brackets [] not{}or () for concentration and don't worry about subscripting or superscripting
(1) magnesium carbonate
(2) calcium phosphate
(3) silver sulfide
Answer:
See explanation
Explanation:
The term ion product is an expression that does not necessarily reflect equilibrium conditions which can be used to determine the concentration of ions in a solution of the stated substance. As a matter of fact, the ion product is different from the solubility product which reflects equilibrium conditions.
The ion product of the following substances are shown below;
magnesium carbonate - MgCO3
MgCO3(aq) -------> [Mg^2+] [CO3^2-]
calcium phosphate - Ca3(PO4)2
Ca3(PO4)2(aq) --------> [Ca^2+]^3 [PO4^3-]^2
silver sulfide - Ag2S
Ag2S(aq) --------> [Ag^+]^2 [S^2-]
Skin color variations were caused by:
a). The change in melanin, the skin's brown pigment
b). The climate of where people migrated to
c)Diets that are rich in Vitamin D
d) All of the above
I'm certain the answer is D: All of the above, but please correct me if I'm wrong ^^
Describe how naturally
acidic rainwater can affect a
mountain of limestone.
Answer:
The naturally acidic rain will gradually wear the mountain of limestone away.
Hope it helps!
The temperature of an oxyacetylene torch flame can reach as high as 3137 °C. What is this temperature in Fahrenheit and Kelvin? Please show work.
Answer:
A)3410K
B)5678.6 °F
Explanation:
✓ To convert Celcius to Kelvin expression below can be used
K= °C + 273
We were given T=3137 °C
= 3137 + 273= 3410K
✓To convert Celcius to Fahrenheit, expression below can be used
°F =(°C × 9/5) + 32
We were given T=3137 °C
°F= (3137 × 9/5) + 32
= 5646.6+32
=5678.6 °F
In the carbon cycle, carbon is transferred from animals to plants by which of the following?
A. carbon dioxide
B. oxygen
C. sugars
D. water
Answer:
A carbon dioxide
its how carbon is transferred
Carbon cycle is the process of balancing the amount of carbon in the atmosphere and what is present in plants and animals. In carbon cycle, carbon is transferred in the form of carbon dioxide from animals to plants.
What is carbon cycle?Carbon cycle is a geochemical cyclic process by which the carbon gas is exchanged between the atmosphere and biosphere. Carbon is the main content of all biological materials as well as living.
These events in carbon cycle balance the amount of carbon in atmosphere and biosphere to sustain life. Thus the wasted carbon from animals are recycled back to the atmosphere in the form of carbon dioxide.
We intake oxygen and release carbon dioxide. The released carbon dioxide is uptaken by plants and used for photosynthesis. By the process of photosynthesis, plants are making glucose and energy.
Therefore, In the carbon cycle, carbon is transferred from animals to plants in the form of A. carbon dioxide.
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A computer randomly puts a point inside the rectangle. What is the probability
that the point does not land in triangle T?
8
4
4
S
LO
T
2
7
O A.
O B. 13
C. }
CON 002
D.
3
Answer:
c
Explanation:
Question 1
Which of the following types of electromagnetic radiation has the shortest wavelengths?
A. Infrared
B. Ultraviolet
C. Visible light
D. Radio waves
Electromagnetic radiation is the energy waves with various wavelengths. Ultraviolet rays have the shortest wavelength. Thus, option B is correct.
What is wavelength?A wavelength is a ratio of the velocity and the frequency as the distance between the crests is measured. The shortest wavelength haves the largest frequency.
Radio waves have the longest wavelength but the shortest frequency and similarly the gamma rays have the shortest wavelength. Ultraviolet rays come before the X-rays and the gamma rays have a short wavelength.
Therefore, option B. UV rays have the shortest wavelength.
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