Answer:
e. I, At
Explanation:
Hello!
In this case, since the periodic trends of a series of elements belonging to the same group towards physical and chemical properties tend to be the same when closer in period, we notice that Mg and Al, Br and Kr and As and Br are close but in period, not in the same group; therefore e. I, At, iodine and astatine, are going to tend to exhibit the greatest similarity in their physical and chemical properties.
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Enter your answer in the provided box. Muriatic acid, an industrial grade of concentrated HCl, is used to clean masonry and cement. Its concentration is 11.7 M. For routine use, a diluted solution of 3.50 M is prepared. How many milliliters of 3.50 M muriatic acid solution contain 32.8 g of HCl
Answer:
257 mL
Explanation:
Step 1: Given data
Concentration of the muriatic acid solution used (C): 3.50 M (3.50 mol/L)Mass of HCl (m): 32.8 gStep 2: Calculate the moles (n) corresponding to 32.8 g of HCl
The molar mass of HCl is 36.46 g/mol.
32.8 g × 1 mol/36.46 g = 0.900 mol
Step 3: Calculate the volume (V) of solution required
We will use the following expression.
C = n/V
V = n/C
V = 0.900 mol/(3.50 mol/L)
V = 0.257 L = 257 mL
An scientist located a nugget of an unknown substance. However, he determined that this nugget has a
mass of 63 g and a volume of 9 cm^3. What is the density of this nugget?
Answer: The density of this nugget is [tex]7\text{ g cm}^{-3}[/tex] .
Explanation:
We are given that,
Mass of nugget = 63 g
Volume = [tex]9\ cm^3[/tex]
The computation of density of a substance is given by :-
[tex]\text{Density}=\dfrac{\text{Mass}}{\text{Volume}}\\\\\Rightarrow\ \text{Density}=\dfrac{63}{9}\text{ g cm}^{-3}[/tex]
[tex]\Rightarrow\ \text{Density =}7\text{ g cm}^{-3}[/tex]
Therefore, the density of this nugget is [tex]7\text{ g cm}^{-3}[/tex] .
A purified protein is in a HEPES buffer at pH 7.0 with 600 mM NaCl. A 1 mL sample of the protein solution is dialyzed against 1.0 L of the same HEPES buffer with 0 mM NaCl. Once the dialysis has come to equilibrium, what is the concentration (in mM) of NaCl in the protein sample
Answer:
Explanation:
Using the dilution formula to determine the final concentration of NaCl in the protein sample.
[tex]M_1V_1 = M_2V_2[/tex]
[tex]600 \ mM \times 1 \ mL= M_2 \times ( 1000\ mL + 1 \ mL)[/tex]
[tex]M_2= \dfrac{600 \ mM \times 1 \ mL}{ ( 1001\ mL)}[/tex]
[tex]M_2= 0.599 \ mM[/tex]
However, when dialysis attains equilibrium, it implies that the sample was dialyzed twice, SO:
[tex]M_2 = \dfrac{600 \ mM\times 1 \ mL}{201 \ mL} = 2.97 \ mM[/tex]
Now, take the concentration as 2.97 mM
Then:
[tex]M_f = \dfrac{2.985 mM \times 1 mL}{201 \ mL}[/tex]
[tex]M_f = 0.01485 \ mM[/tex]
[NaCl] = 0.01485 mM
Plz help guys help me
Answer:
Six Steps to Control Workplace Hazards
Step 1: Design or re-organise to eliminate hazards. ...
Step 2: Substitute the hazard with something safer. ...
Step 3: Isolate the hazard from people. ...
Step 4: Use engineering controls. ...
Step 5: Use administrative controls. ...
Step 6: Use Personal Protective Equipment (PPE)
Explanation:
i it true?
What is the structure formula of c10h18
Answer: I'm not 100% sure this is the formula but I hope it still helps! :)
Explanation:
Bornane; Cyclodecene; Decalin; Decynes. 1-Decyne; 2-Decyne; 3-Decyne; 4-Decyne; 5-Decyne, also known as dibutylethyne; Spirodecane
Which factors directly affect the magnetic force produced by an electromagnet?
O number of turns in the wire, amount of current
O amount of current, type of force
O length of core, number of turns in the wire
O amount of current, length of core
The number of atoms in 10. grams of calcium is equal to 6.0 x 1023 multiplied by which number?
Answer:
1.51×10²³ atoms.
Explanation:
From the question given above, the following data were obtained:
Mass of Calcium (Ca = 10 g
Number of atom of Calcium (Ca) =?
The number of atoms present in 10 g of Ca be obtained as follow:
From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms. This implies that 1 mole Ca contains 6.02×10²³ atoms.
1 mole of Ca = 40 g.
Now, if 40 g of Ca contains 6.02×10²³ atoms.
Therefore, 10 g of Ca will contain = (10 × 6.02×10²³) / 40 = 1.51×10²³ atoms.
Thus, 10 g of calcium contains 1.51×10²³ atoms.
Why is it sometimes not practical to use scale models when representing objects in space?
well space base stars and I'm done know
Explanation:
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Sometimes making a scale model is not practical because it is expensive and takes a lot time to build up for large models of objects. Rebuilding of destroyed scale models is very difficult.
What is scale model ?A physical model that is geometrically comparable to an item is called a scale model . Scale models may be larger than small prototypes like anatomical structures or subatomic particles, but they are often smaller than huge prototypes like cars, buildings, or people.
Mockups are models created at the same scale as the prototype. In addition to being used as toys, scale models are also utilized as tools for engineering design and testing, marketing, and sales, as well as for military strategy and special effects in movies.
The pursuit of model construction as a pastime for artistic purposes is also common. However, it is very expensive and time consuming to create a scale model.
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a A student decreases the temperature of a 484 cm ^ 3 balloon from 570 K to 285 Assuming constant pressure, what should the new volume of the balloon be? Round your answer to one decimal place.
Answer:
242 cm³.
Explanation:
The following data were obtained from the question:
Initial volume (V₁) = 484 cm³
Initial temperature (T₁) = 570 K
Final temperature (T₂) = 285 K
Pressure = constant
Final volume (V₂) =?
The new volume (i.e final volume) of the balloon can be obtained by using the Charles' law equation as illustrated below:
V₁/T₁ = V₂/T₂
484 / 570 = V₂ / 285
Cross
484 × 285 = 570 × V₂
137940 = 570 × V₂
Divide both side by 570
V₂ = 137940 / 570
V₂ = 242 cm³
Therefore, the new volume of the balloon is 242 cm³
Which statement is always true about conversation of matter?
The mass of a system does not change during a chemical reaction
If a solid forms the mass of a system increases
If a gas forms the mass of a system decreases
The mass of a system changes when a substance changes from liquid to gas, but it does not change in a chemical reaction
Answer:
The mass of a system does not change during a chemical reaction
Explanation:
Correct Answers
According to bond energy tables, the triple bond of N2 is 946 kJ/mol while the bond of I2 is 151 kJ/mol. Based on simple chemical ideas about what molecular properties lead to activation energies, it is reasonable to expect that the reaction of H with N2 will have a higher activation energy than the reaction of H with I2.
1. Yes, I2 is heavier than N2.
2. No, bond energies do not matter much; lone pairs are crucial.
3. Yes, in both cases the reactant bond must be stretched by collisions and more energy is required for the stronger bond.
4. Yes, in both cases the reactant bond must be broken before the H can bond.
5. No, activation energies have nothing to do with bond energies.
Answer:
Yes, in both cases the reactant bond must be broken before the H can bond.
Explanation:
Let us remind ourselves of the basics of the collision theory. According to this theory, chemical reaction occurs because of the collision of particles of substances in a chemical reaction system.
This means that the bond between reactants must first be broken and new bonds formed in products. Activation energy is the minimum energy required for a reaction to occur. This energy goes into the rearrangement of reactant bonds to enable them to recombine and form products.
Since the N2 bond energy is far higher than the I2 bond energy, a greater degree of energy is needed overcome the energy barrier in the reaction of H2 with N2 compared to the reaction of H2 and I2 . Therefore, the activation energy for the reaction of H2 and N2 is much higher than the activation energy for the reaction of H2 with I2.
I need your help please thank you so much?!?!?
Answer:
The end products cannot be changed back in their original forms
Explanation:
Answer:
the first one
Explanation:
A student performs an experiment to determine the molar mass of magnesium oxide. The student repeats the experiment five times and collects the following data: 40.220gmol, 40.654gmol, 40.314 gmol, 40.165 gmol, and 40.554 gmol. If the accepted value for the molar mass is 40.304 gmol, what is the percent relative error for the average of this data?
Answer:
Percent relative error = 0.191%
Explanation:
Relative error is a measure of accuracy (How closeness is the measure to the accepted value) for a determined data. The formula is:
Percent relative error = |Experimental - Accepted| / Accepted * 100
Where experimental is the average of the data:
(40.220g/mol + 40.654g/mol + 40.314g/mol + 40.165g/mol + 40.554g/mol) / 5 =
40.381g/mol
Replacing using accepted value = 40.304g/mol:
|40.381g/mol - 40.304g/mol| / 40.304g/mol * 100
Percent relative error = 0.191%Which statement about Niels Bohr's atomic model is true?
O Higher orbits have lower energies.
O Each orbit has a specific energy level.
O Electrons can exist in any energy level.
O Orbits close to the nucleus have no energy.
Answer:
O Each orbit has a specific energy level.
Explanation:
Neils Bohr put forward his own model of the atom based on the quantum mechanics originally developed by Planck.
He assumed the Rutherford's model and suggested that the extranuclear part consists of electrons in specific spherical orbits around the nucleus.
The orbits/energy level are the permissible through which the electrons can move through.
His concept is based the concept that the electron can move round the nucleus in certain permissible orbitss
Riboflavin is one of the B vitamins It is also known as B6 and is made up of carbon, hydrogen, nitrogen and oxygen atoms. When 10.0 g of vitamin B6 is burned in oxygen, 19.88 g of CO2 and 4.79 g of H2O are obtained. Another experiment shows that vitamin B6 is made up of 14.89% of N. What is the simplest formula for vitamin B6
Answer:
C₁₇H₂₀N₄O₆
Explanation:
First, we need to determine the percentage of the atoms in the molecule. Then, assuming a basis of 100 we must convert the mass of each atom to moles. Simplest formula is the simplest ratio of atoms presents in the molecule:
%C:
19.88g CO2 * (12.01g/mol C / 44.01g/mol CO2) = 5.425g C
5.425g C / 10.0g * 100 = 54.25% C
%H:
4.79g H2O * (2*1.01g/mol / 18.015g/mol) = 0.537g H
0.537g H / 10.0g * 100 = 5.37%
%N:
14.89%
%O:
100 - 14.89% - 54.25% - 5.37% = 25.49%
Moles of each atom in a basis of 100g:
C: 54.25g * (1mol / 12.01g) = 4.517moles
H: 5.37g * (1mol / 1.01g) = 5.317 moles
N: 14.89g * (1mol / 14.01g) = 1.063 moles
O: 25.49g * (1mol / 16g) = 1.593 moles
Dividing each amount of moles in the lower number of moles (moles N):
C = 4.517mol / 1.063mol = 4.25
H = 5.317mol / 1.063mol = 5
N = 1.063mol / 1.063mol = 1
O = 1.593mol / 1.063mol = 1.5
This ratio multiplied 4 times to obtain whole-numbers:
C = 4.25*4 = 17
H = 5*4 = 20
N = 1*4 = 4
O = 1.5*4 = 6
The simplest formula for vitamin B6 is:
C₁₇H₂₀N₄O₆According to the Michaelis-Menten equation, when an enzyme is combined with a substrate of concentration s (in millimolars), the reaction rate (in micromolars/min) is
Answer:
The answer is "A"
Explanation:
Please find the complete question in the attachment file.
[tex]\to R(s)= \frac{As}{K+s}[/tex]
when the s in the approach, that is infinity R(s) tends
[tex]\to \frac{A}{\frac{K}{s}+1} \\\\ \to\frac{A}{0+1} \\\\ \to\frac{A}{1} \\\\ \to A[/tex]
a dragster in a race accelerated from rest to 60 m/s by the time it reached the finish line. the dragster moved the distance from start to finish in 8.3 seconds. what is the dragsters acceleration?
i’ll mark brainliest!!
Answer:
7.23m/s²
Explanation:
Given parameters:
Initial velocity = 0m/s
Final velocity = 60m/s
Time taken = 8.3s
Unknown:
Acceleration of the dragsters = ?
Solution:
Acceleration is defined as the rate of change of velocity with time taken.
So;
Acceleration = [tex]\frac{Final velocity - Initial velocity }{time}[/tex]
Acceleration = [tex]\frac{60 - 0}{8.3 }[/tex] = 7.23m/s²
Today, ammonia is synthesized through a series of reactions (called the Haber-Bosch process) that take place between methane, air (which is four parts N2, one part O2), and potassium carbonate:
7 CH4(g) + 8 N2(g) +2 O2(g) + 17 H2O(g) + 7 K2CO3(s) ?? 16 NH3(g) + 14 KHCO3(s)
What is the equilibrium expression for the Harber-Bosch process?
Answer:
K = [NH₃]¹⁶ [KHCO₃]¹⁴ / [CH₄]⁷ [N₂]⁸ [O₂]² [H₂O]¹⁷ [K₂CO₃]⁷
Explanation:
The equation for the reaction is given below:
7CH₄(g) + 8N₂(g) +2O₂(g) + 17H₂O(g) + 7K₂CO₃(s) —> 16NH₃(g) + 14KHCO₃(s)
Equilibrium constant (K) =..?
Equilibrium constant, K for a reaction is simply defined as the ratio of the concentration of the products raised to their coefficient to the concentration of the reactants raised to their coefficient.
Thus, the equilibrium expression for the Harber-Bosch process for the synthesis of ammonia can be written as shown below:
K = [NH₃]¹⁶ [KHCO₃]¹⁴ / [CH₄]⁷ [N₂]⁸ [O₂]² [H₂O]¹⁷ [K₂CO₃]⁷
Joaquin tells his science class that galaxies consist of gas, dust, and many planets. What is the most important component of galaxios Joaquin is missing in his description?
astero de
comets
constellations
Stars
Answer:
the answer is asteroids!
Explanation:
Answer:
astroid
Explanation:
becaus
Many compressed gases come in large, heavy metal cylinders that are so bevy that they need a special cart to move them around. An 80.0-L tank of nitrogen gas pressurized to 172 arm atm is left in the sun and heats from its normal temperature of 20.0 degrees Celsius to 140.0 degrees Celsius. Determine (a) the final pressure inside the tank and (b) the work, heat, and delta U of the process. assume that behavior is ideal and the heat capacity of diatomic nitrogen is 21.0 j/molk.
Answer:
a) final pressure inside the tank is 242.4 atm
b)
Work = 0
heat q = 1440.85 kJ
DU = 1440.85 kJ
Explanation:
Given that;
Pressure P1 = 172 atm
Volume V = 80 L
Temperature T1 = 20°C = ( 273.15 + 20) = 293.15 K
Temperature T2 = 140°C = ( 273.15 + 140) = 413.15 K
we know that, gas constant R = 0.0821 atm.L/mol.K
from the Ideal Gas equation;
pV = nRT1
n = pV/RT1
we substitute
n = (172 × 80) / (0.0821 × 293.15)
n = 13760 / 24.067615
n = 571.72 moles
now
P2 = nRT2/V2
P2 = (571.72 × 0.0821 × 413.15) / 80
P2 = 19392.5222 / 80
P2 = 242.4 atm
Therefore, final pressure inside the tank is 242.4 atm
b)
we know
w = -∫[tex]P_{ext}[/tex] dv
now, since there is no change in volume; dv = 0
so
w = 0
Work = 0
dU = cVDT
Cv = nCr,m
Cv = 571.72 × 21.0
Cv = 12007.12 J/k
DU = CvΔT
DU = 12007.12 × (413.15 - 293.15)
DU = 1440854.4 J
DU = 1440.85 kJ
DU = q + w
1440.85 = q + 0
heat q = 1440.85 kJ
PLZ HELP ASAP WILL GIVE BRAINLISTS TO RIGHT ANSWER
How many molecules of carbon dioxide are in 12.2 L of the gas at STP?
A) 3.28 x 10^23 molecules
B) 5.01 X 10^23 molecules
C)2.24 x 10^23 molecules
D)8.12 x 10^22 molecules
Answer:
c
Explanation:
ok than not c than b maybe
How can you model the cycling of matter in the Earth system?
Answer:
The cycling of matter is important to many Earth processes and to the survival of organisms the existing matter must cycle continuously for this planet to support life Water, carbon, nitrogen, phosphorus, and even rocks move through cycles If these materials did not cycle, Earth could not support life.
Explanation:
Earth activities depend on matter cycling, and for organisms to survive, this planet's surface must cycle with the flow of matter.
What is Earth system?Rocks, as well as water, carbon, nitrogen, and phosphorus, go through cycles. The planet Earth could not support life if these materials did not cycle.
Subsystems exist within the Earth system. These subsystems include the exosphere, atmosphere, hydrosphere, lithosphere and geosphere, also referred to as the lithosphere, and the living environment (biosphere).
These systems are powered by energy that comes from both the Sun and the interior of the Earth. Through processes known as biogeochemical cycles, nutrients and elements also move through these systems along with energy.
Therefore, Earth activities depend on matter cycling, and for organisms to survive, this planet's surface must cycle with the flow of matter.
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What is the charge is the ion when lithium reacts with chlorine
2.Your culture media recipe says you need to add 2.625g of Sodium Bicarbonate per liter of media. You realize you only have a 7.5% solution of Sodium Bicarbonate you can use. What volume of that solution can you add, while making your media, to have the necessary mass of NaHCO3
Answer:
35mL of the 7.5% solution are required to meake the media
Explanation:
To prepare the culture media there are required 2.625g of sodium bicarbonate. We have a 7.5% solution of sodium bicarbonate (That is, 7.5g of sodium bicarbonate in 100mL of solution). Thus, to obtain 2.625g we need:
2.625g Sodium bicarbonate * (100mL / 7.5g) =
35mL of the 7.5% solution are required to meake the mediahelppp nowwww plsssss!!
Answer:
The sun will appear to rise and set more slowly
have a nice day! (^o^)
Which element is classified as a transition metal?
A) lithium (Li)
B) zirconium (Zr)
C) tellurium (Te)
D) xenon (Xe)
Answer:
C) tellurium (Te) is the correct answer.
What role do wolves play in the tundra?
Answer:
predator
Explanation:
Wolves, arctic foxes, and snowy owls are predators in the tundra.
Experiments were done on a certain pure substance X to determine some of its properties. There's a description of each experiment in the table below. In each case, decide whether the property measured was a chemical or physical property of X, if you can. If you don't have enough information to decide, choose can't decide in the third column.
Property P: A small sample of X is dissolved in water. Drops of another solution, containing dissolved sodium hydroxide, are slowly added, and a pH indicator is used to determine when the sodium hydroxide has completely reacted with X. From the amount of sodium hydroxide needed, the value of P may be calculated.
Property D: A sample of X is carefully weighed and put inside a vented flask. Water is added to the flask until it just covers the sample, and the volume of sample and water is recorded. Then the sample is removed and the volume of water alone recorded. From the mass of the sample and the difference in volumes, the value of R may be calculated.
Property V: Sample of X is melted and put into a reservoir from which a very thin tube leads down. The rate at which X flows out of the tube is measured, and from this rate the value of V may be calculated.
Answer:
The property P measured, was a chemical property of X; its acidity
The property D measured, was a physical property of X; its density
The property V measured, was a physical property of X; it's viscosity probably.
Explanation:
1. The property V that was measured is the acidity of X. The acidity of X is a measure of the concentration of hydrogen ions present in it. When drops of another solution, containing dissolved sodium hydroxide, are slowly added, and a pH indicator is used to determine when the sodium hydroxide has completely reacted with X, the procedure determines the concentration of X that would neutralize the base, sodium hydroxide.
2. The property of X determined in the step is the density of X, a physical property. First the volume of X was determined by the displacement method. Then the density of X is calculated from its mass and volume.
3. Since during the determination of the property V, there was no alteration done to the chemical constitution of X, the property thus determined is a physical property. Melting of the sample is a physical change and likewise its flow rate through a very thin tube.
ASAP I WILL GIVE BRAINLIEST The diagram shows a lever. What is the mechanical advantage of the lever? O 2 03 3 m 6 m mi 0 9
Answer:
A) 2
Explanation:
Answer:
2, i got it right thanks to the other user :) <3
Explanation:
A cold air mass and a warm air mass are predicted to meet. What type of weather can be expected between the two air masses?
A.
warm weather
B.
cold weather
C.
dry weather
D.
stormy weather
Answer:
Explanation:
C. warm weather
Answer:
stormy weather