Answer: Only non-polar medicines can diffuse across the membrane. non-polar drugs are lipid soluble, while polar drugs are water soluble, so polar drugs cant absorb through biological membranes.
What contains more hydrogen atoms, 1.0 mole of H20 or 1.0 moles of НЗО?
H20
H30
both are equal
cannot be determined
(please show ur work)
How many moles are in 3.01 x 10^23 atoms of zinc?
Answer:
What is ^ for?
Explanation:
A first order reaction has a rate constant of 0.924 at 25 oC. Given that the activation energy is 89.8 kJ/mol, calculate the rate constant at 33.3 oC.
Answer:
[tex]k_2=2.46[/tex]
Explanation:
Hello!
In this case, according to the Arrhenius equation for variable temperature:
[tex]ln(\frac{k_2}{k_1} )=-\frac{Ea}{R}(\frac{1}{T_2} -\frac{1}{T_1} )[/tex]
Given the temperatures to be computed in kelvins and the activation energy, we obtain:
[tex]ln(\frac{k_2}{0.924} )=-\frac{89800J/mol}{8.314J/(mol*K)}(\frac{1}{306.45K} -\frac{1}{298.15K} )\\\\ln(\frac{k_2}{0.924} )=0.981\\\\k_2=0.924*exp(0.981)\\\\k_2=2.46[/tex]
Best regards!
What are essential elements in plants?
Answer:
Chlorophyll is one. I can't quite remember other
Sam is pushing a large rock over the ground. ALL BUT ONE of the following terms relates to the movement of the rock. What term is it? A) force B) friction C) mass D) size
Answer:
C) Mass
Explanation:
What is the name of the process happening in the picture? How do you know it’s that process? Explain your answer in 2 to 3 complete sentences
Which individual elements make up the following common
compounds?
CaCO 3
CaCl 2
C H O 3 6
HCl
Ca(OH) 2
Answer:
I think it will carbon hope it helps
I need some help to determine the mole and grams pls I would really appreciate the help
Answer:
[tex]n_{FeS}=0.686molFeS \\\\n_{H_2S}=23.3gH_2S[/tex]
Explanation:
Hello!
In this case, according to the given chemical reaction, it is possible to apply the following stoichiometric setups in order to compute the moles of reacting FeS and the grams of produced H2S, given the mass of HCl (molar mass = 36.46 g/mol) as shown below:
[tex]n_{FeS}=50.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molFeS}{2molHCl}\\\\n_{FeS}=0.686molFeS \\\\\\m_{H_2S}=50.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molH_2S}{2molHCl}*\frac{34.04gH_2S}{1molH_2S} \\\\n_{H_2S}=23.3gH_2S[/tex]
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Help pls!!!!!!!!!!!!!!!!!!!!!!!!!
Chief Keef - Love Sosa
Deforestation happens when people try to provide more:
a) water
b) waste
c) timber
d) oxygen.
Mercury is the only metal that is a liquid at room temperature. When mercury vapor is inhaled, it is readily absorbed by the lungs, causing signifiant health risks. The enthalpy of vaporization of mercury is 59.1 kJ/mol. The normal boiling point of mercury is 357°C. What is the vapor pressure of mercury at 43°C? Assume the enthalpy of vaporization does not depend on temperature.
Answer:
P = 0.0166 mm Hg
Explanation:
To solve this question, we need to use the Clausius Clapeyron equation, which is a commonly used expression to calculate vapour pressure at a given temperature. We have the enthalpy of vaporization of the mercury, so, let's write the equation:
Clausius Clapeyron equation:
Ln (P₂ / P₁) = (-ΔHv / R)(1/T₂ - 1/T₁) (1)
Where:
R: universal constant of gases (8.314 J / K.mol)
P₂: Vapour pressure at 43°C (or 316 K)
P₁: Pressure of mercury at the boiling point (1 atm)
T₂: temperature at 43 °C
T₁: Boiling point of mercury (357 °C or 630 K)
As we are given the boiling point of the mercury, we can safely assume that the pressure at this point is 1 atm, becuase remember that when a sustance boils, is because it's internal pressure has reached the atmospherical pressure of 1 atm. With this clear, all we just need to do is solve for P₂. We are going to do this very slowly so you can understand the process. First let's replace the given data:
Ln (P₂ / 1) = (-59100 J/mol / 8.314 J / K.mol) (1/316 - 1/630)
Ln P₂ = -7108.49 * (3.16x10⁻³ - 1.59x10⁻³)
Ln P₂ = -7108.49 * (1.51x10⁻³)
Ln P₂ = -10.7338
P₂ = 10⁽⁻¹⁰°⁷³³⁸⁾
P₂ = 2.18x10⁻⁵ atm
We can express this value in mm Hg and it will be:
P₂ = 2.18x10⁻⁵ * 760
P₂ = 0.0166 mm HgHope this helps
which changes when gases condense to form liquids
In condensation, matter changes from a gas to a liquid. All matter is made of tiny moving particles called molecules. Evaporation and condensation happen when these molecules gain or lose energy. This energy exists in the form of heat.
Question 12 (1 point)
You notice light pollution in
a.space
b.big cities
c.rural areas
d.our galaxy
Answer:
the answer is D . our galaxy
Answer:
our galaxy of course
How to get the density of this unknown liquid?
Answer:
Measure the volume of water poured into a graduated cylinder, then place the object in the water and remeasure the volume. The difference between the two volume measurements is the volume of the object. Now simply divide the mass by the volume to calculate the density of the object.
David Robinson, a professional basketball
player, is 7 ft, 1.0 in. tall. Convert his height to
centimeters
Show work please
Answer:
215.9 cm
Explanation:
1 foot= 30.5cm
30.5cm times 7 1/12=215.9cm
The given height of David is 7 ft, 1.0 inch, so in centimeters, the height will be 216.4 cm.
What is unit conversion?A conversion factor is a number that is used to multiply or divide one set of units into another. When converting to an equal value, the appropriate conversion factor must be used.
We must convert one unit to another in order to achieve accuracy and avoid measurement confusion.
We do not, for example, measure the length of a pencil in kilometers. In this case, one must convert kilometers (km) to centimeters (cm) (cm).
To convert feet to centimeters, multiply the given foot length by 30.48 cm.
So,
Height in cm will be = 7.1 x 30.48
Height in cm = 216.4cm
Thus, the height of David in centimeters is 216.4 cm.
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please help. it’s my last question.
Given
Atomic symbol
Required
Atomic composition
Solution
Atomic number = number of protons = number of electrons
Mass Number (A) is the sum of protons and neutrons
Number of protons and Number of Neutrons in nucleus
Number of electrons in the shell
From the picture:
protons = 3
neutrons = 4
electrons = 3
atomic number = protons = electrons = 3
mass number = protons + neutrons = 3+4 = 7
PLEASE HELP this is physical science.
Bone age : 22,920 years
Further explanationGiven
Nt = 2.5 g C-14
No = 40 g
half-life = 5730 years
Required
time of decay
Solution
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}[/tex]
t = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
Input the value :
[tex]\tt 2.5=40.\dfrac{1}{2}^{t/5730}\\\\\dfrac{2.5}{40}=\dfrac{1}{2}^{t/5730}\\\\(\dfrac{1}{2})^4=\dfrac{1}{2}^{t/5730}\\\\4=t/5730\rightarrow t=22920~years[/tex]
You are working to earn enough money for a vacation which costs 2100. Your take-home pay is $16.50/hour, but you only work 4-hour shifts each day. How many days will it take for you to earn enough money to pay for your vacation if all the money you earn goes towards your vacation?
Answer:
32 days.
Explanation:
First we determine how much is made in a day.
16.50 x 4 = 66.
Next, we divide 2100 by 66 to reach our amount of days needed.
2100 / 66 = 31.818181... [81 is what repeats over and over.]
We round this up to the nearest whole number. You can't underpay, so you have to round.
The next whole number would be 32, so our answer is 32 days.
Two units of distance used by scientists to describe distances in space are the light-year and astronomical unit. Why do scientists use the light-year instead of Astronomical Units to measure the distances between stars?
The speed of sound is too slow.
Telescopes can measure only in light years
Distant stars can only be seen if there is light
The smaller numbers that result from measuring with larger units are easier to use
Answer:
The smaller numbers that result from measuring with larger units are easier to use .
That’s the one, good luck!
The smaller numbers that result from measuring with larger units are easier to use.
Light year is a unit of astronomical distance that measures the distance traveled by light in one year. The distance between stars can also be measured using parsecs.
The equivalent of this distance in various units is written as follows;
1 light year (ly) = 9.5 x 10¹² km = 63,240 AU1 parsec = 3.26 lyUsing light year to represent the unit of distance is more concise because big measurement can be represented easily with small numbers using this large unit.
Thus, we can conclude that the smaller numbers that result from measuring with larger units are easier to use.
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According to the following reaction, how many moles of calcium chloride will be formed upon the complete reaction of 27.9 grams of calcium hydroxide with excess hydrochloric acid? calcium hydroxide (aq) + hydrochloric acid (aq) calcium chloride (aq) + water (l) moles calcium chloride
Answer: 0.377 moles of calcium chloride will be formed.
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} Ca(OH)_2=\frac{27.9g}{74g/mol}=0.377moles[/tex]
The balanced chemical reaction is:
[tex]Ca(OH)_2+2HCl\rightarrow CaCl_2+2H_2O[/tex]
According to stoichiometry :
As 1 mole of [tex]Ca(OH)_2[/tex] give = 1 mole of [tex]CaCl_2[/tex]
Thus 0.377 moles of [tex]Ca(OH)_2[/tex] give =[tex]\frac{1}{1}\times 0.377=0.377moles[/tex] of [tex]CaCl_2[/tex]
Thus 0.377 moles of calcium chloride will be formed upon the complete reaction of 27.9 grams of calcium hydroxide with excess hydrochloric acid
Convert 3.93 x 10-22 grams of X4Z3 into molecules/formula units of the same compound. (Assume that the molar mass of X is 59.45 grams per mole and the molar mass of Z is 13.84 grams per mole.)
Assume that Avogadro's number is 6.022 x 1023. Report your answer to three decimal places.
Answer:
0.847 molecule.
Explanation:
From the question given above, the following data were obtained:
Mass of X₄Z₃ = 3.93×10¯²² g
Number of molecules of X₄Z₃ =?
Avogadro's number = 6.022×10²³ molecules
Next, we shall determine the molar mass of X₄Z₃. This can be obtained as follow:
Molar mass of X₄Z₃ = (4×59.45) + (3×13.84)
= 237.8 + 41.52
= 279.32 g/mol
Finally, we shall determine the number of molecules in 3.93×10¯²² g of X₄Z₃. This can be obtained as follow:
From Avogadro's hypothesis,
1 mole of X₄Z₃ = 6.022×10²³ molecules
But 1 mole of X₄Z₃ = 279.32 g
Thus we can say that:
279.32 g = 6.022×10²³ molecules
Therefore,
3.93×10¯²² g = 3.93×10¯²² × 6.022×10²³ / 279.32
3.93×10¯²² g = 0.847 molecule.
Thus, 3.93×10¯²² g of X₄Z₃ contains 0.847 molecule.
ANSWER ASAP
2. The figure shows the first three rows, or periods, of the periodic table. Suppose the fourth period is added. How many orbits will the Bohr models in the fourth period have? How many electrons will an atom in Group 1 in the fourth period have?
Answer:
4 orbits in the fourth period.
19 electrons in the atom from group 1 and fourth period.
Explanation:
Potassium has 19 electrons distributed in its 4 orbits
The number of periods in a periodic table, tells the number of shells or orbitals of the atoms in that row in which the electrons are filled. Thus the fourth period elements have 4 orbitals and the first element in group one of the fourth period is potassium containing 19 electrons.
What are periods in periodic table?All elements in a periodic table are classified into different groups and periods. The vertical columns in the periodic table is called groups and the horizontal rows are called periods.
A group contains elements with same number of valence electrons and similar physical and chemical properties. In a period from left to right the atomic number increases but the number of orbitals in which the electrons are filled will be the same.
Down a group the number of orbitals increases by one. Thus, each elements contains electrons in an increment of 8, 18, 18 and 32 down a group. Thus, from third period to fourth period the number of orbital increases to 4.
The number of electrons will be +8 from the previous element in the group in third period. Thus, below sodium (11) the first element in fourth period is potassium with 19 electrons.
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How many carbon atoms are represented by Mg(HCO3)
Determine the density (in g/mL) of a substance with a mass of 105 g and a volume of 17.6 mL.
Answer:
Density, d = 5.96 g/mL
Explanation:
Given that,
Mass, m = 105 g
Volume, V = 17.6 mL
We need to find the density of the substance. So,
[tex]d=\dfrac{m}{V}\\\\d=\dfrac{105\ g}{17.6\ mL}\\\\d=5.96\ g/mL[/tex]
So, the density of the substance is 5.96 g/mL.
Help ASAP please
Which statement best describes the reaction pathway graph for an exothermic reaction but not an endothermic reaction?
It has a hill in the middle that is the highest point.
It has a valley in the middle that is its lowest point.
The reactants are higher in energy than the products.
The products are higher in energy than the reactants.
Answer: C ) The reactants are higher in energy than the products
Explanation:
The enthalpy that is a state variable that identifies the content of heat. Then the change of enthalpy for the exothermic reactions is negative, meaning that the energy of the products is lower than the energy of the reactants.
14.86 ml + 15.0 ml + 14.980 ml =
Answer:
44.84 ml
Explanation:
14.86
+
15.0
+
14.980
_______
44.84
Examine the diagram of the cell cycle. Which label identifies the stage in which the DNA is copied and the cell grows? W X Y Z
Explanation:
w is the stage in which dna is copied and cell grows.
Answer:
w
Explanation:
I need helppppppppppp. Btw the question is “Select three populations shown in the prairie ecosystem.”
i think the answer is 6 prairie dogs, 3 coyotes ,the grass
Hope this helps
Have a great day/night
Feel free to ask any questions
(1) Solution A and B are separated by a membrane that is permeable to Mg2 and impermeable to Cl-. Solution A contains 0.1 mM MgCl2, solution B contains 100 mM MgCl2. Mg2 will be at electrochemical equilibrium when solution A is around ____________ mV. 180 mV - 180 mV 90 mV - 90 mV 60 mV - 60 mV
Answer:
90 mV
Explanation:
Faraday constant, F = 96487
Gas constant, R = 8.314
Number of mole of electron transferred, Z = 2
MgCl in solution A, = 0.1 mm
MgCl in solution A, = 100 mm
Using the relation :
E=(RT/ZF) In(Mg out/Mgin)
E = (8.314*298) / (2*96485) * In(100/0.1)
E = (2477.572 / 192970) * 6.9077552
E = 0.0128391 * 6.9077552
E = 0.0886897 V
E = 88.68 mV (approximately 90 mV)
How many liters of N2 gas are in 2.4 moles at STP?
Answer:
any gas takes up 22.4L per mole so 2.4*22.4=53.76
Explanation:
In 2.4 moles at STP, 53.79 litres of N2 gas are present.
What are moles?Moles are defined as the amount of substance of a system that contain the same number of entities as the number of atoms in 12g of carbon 12.
What is STP?STP is defined as the standard temperature and pressure. At STP, as system has s temperature of zero degree centigrade or 273 Kelvin and the pressure is 1 atm.
PV= nRT
P= 1 atm
V= ?
n= 2.4 moles
R= 0.0821 L atm /K/mol
1 x V = 2.4 x 0.0821 x 273
V = 53.79 litres
Hence, 53.79 litres of N2 gas is present in 2.4 moles at STP.
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