Answer:
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
Answer:
A covalent bond is the “interatomic linkage that results from the sharing of an electron pair between two atoms.”
Explanation:
Hope this helps have a nice day
How many species are known to be living on Earth?
Answer:
8.7 million species
Explanation:
Scientists have estimated that there are around 8.7 million species of plants and animals in existence.
13. Which has the largest atomic radius?
A. fluorine B. chlorine C. bromine
D. a bromine anion with a charge of 1-
Answer:
bromine
Explanation:
. What mass of ammonium chloride must be added to 250. mL of water to give a solution with pH
4.85? [Kb(NH3) = 1.8 x 10-1
a. 4.7 g
b. 75 g
c.2.3 x 10-ºg
d. 19 g
e.10g
The mass of ammonium chloride that must be added is : ( A ) 4.7 g
Given data :
Volume of water ( V ) = 250 mL = 0.25 L
pH of solution = 4.85
Kb = 1.8 * 10⁻⁵
Kw = 10⁻¹⁴
Given that the dissolution of NH₄Cl gives NH₄⁺⁺ and Cl⁻ ions the equation is written as :
NH₄CI + H₂O ⇄ NH₃ + H₃O⁺
where conc of H₃O⁺
[ H₃O⁺ ] = [tex]\sqrt{Ka.C}[/tex] and Ka = Kw / Kb
∴ Ka = 5.56 * 10⁻¹⁰
Next step : Determine the concentration of H₃O⁺ in the solution
pH = - log [ H₃O⁺ ] = 4.85
∴ [ H₃O⁺ ] in the solution = 1.14125 * 10⁻⁵
Next step : Determine the concentration of NH₄CI in the solution
C = [ H₃O⁺ ]² / Ka
= ( 1.14125 * 10⁻⁵ )² / 5.56 * 10⁻¹⁰
= 0.359 mol / L
Determine the number of moles of NH₄CI in the solution
n = C . V
= 0.359 mol / L * 0.25 L = 0.08979 mole
Final step : determine the mass of ammonium chloride that must be added to 250 mL
mass = n * molar mass
= 0.08979 * 53.5 g/mol
= 4.80 g ≈ 4.7 grams
Therefore we can conclude that the mass of ammonium chloride that must be added is 4.7 g
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A student was asked to determine the concentration of ammonia, a volatile substance used in the clinical setting as a respiretory stimulant to prevent fainting. First the student pipetted 25.00 mL of the cloudy ammonia solution into a 250.0 mL conical flask. 50.00 mL of 0.100 mol L' HCl(aq) was immediately added to the conical flask which reacted with the ammonia in solution. The excess (unreacted) HCI was then titrated with 0.050 mol L- Na2CO3(aq). 21.50 mL of Na2CO3(aq) was required. Calculate the concentration of the ammonia in the cloudy ammonia solution.
This question is describing two chemical equations whereby the concentration of ammonia has to be determined. The first reaction is between 25.00 mL of ammonia and 50.00 mL of 0.100-M HCl whose excess was neutralized with 21.50 mL of 0.050-M Na₂CO₃ and thus, the concentration ammonia in the cloudy solution was determined as 0.114 M.
First of all we need to go over the titration of the excess HCl with Na₂CO₃ by writing the chemical equation it takes place when they react:
[tex]2HCl+Na_2CO_3\rightarrow 2NaCl+CO_2+H_2O[/tex]
Whereas the mole ratio of HCl to Na₂CO₃ is 2:1 and the volume of the HCl leftover is determined as follows:
[tex]V_{HCl}^{leftover}=\frac{2*0.050M*21.50mL}{0.100M} =21.5mL[/tex]
Next, we infer that the consumed volume of HCl by the ammonia solution was:
[tex]V_{HCl}^{consumed}=50.00mL-21.50mL=28.5 mL[/tex]
Then, we write the chemical equation that takes place between ammonia and HCl:
[tex]HCl+NH_3\rightarrow NH_4Cl[/tex]
Whereas the mole ratio is now 1:1, which means that the concentration of ammonia was:
[tex]M_{NH_3}=\frac{28.5mL*0.100M}{25.00mL}\\\\ M_{NH_3}=0.114M[/tex]
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(Titration) https://brainly.com/question/15687419(Titration) https://brainly.com/question/25328286What quantity of energy is required to heat a piece of iron wighing 1.31 g from 25.0 degrees celsius to 46.0 degrees celsius
The quantity of energy required to heat a piece of iron weighing 1.31 g from 25.0 degrees Celsius to 46.0 degrees Celsius is 2.93 calories.
What is energy?The ability or power to perform tasks, such as the ability to move an object (having a certain mass) by exerting force.
Energy can exist in many forms, including electrical, mechanical, chemical, thermal, and nuclear, and it can also change its form.
The equation q = mcT, where m is the sample mass, c is the specific heat, and T is the temperature change, can be used to determine the amount of heat acquired or lost by a sample (q).
Q = mcΔT
Q = 1.31 g x 449 x 21° C = 12.26 joule
12.26 /1 x 1 cal / 4.189= 2.93 calories
Therefore, the quantity of energy required to heat a piece of iron is 2.93 cal.
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I have a hard time telling the difference between convection, conduction, and radiation, anybody got any tips?
How many moles does 205 g of helium,He, contain ?
Answer:
4.002602
Explanation:
Seems Am Converting Between Grams Helium And Mole.
What Is the answers?
Answer:
oxygen is responsible for rusting
Hello do anyone on here no something about Gizmos Fan Cart Physics?
Answer:
yes here is the answer key
for the last question it is a challenge question, here is the answer:
(A) The mass of the cart is 1.214 kg
(B) The mass of one fan is 1.262 kg
(C) The mass of one of the draggable mass units is 3.131 kg
Explanation:
what are nanofluids and how they work?
Answer:
What is nanofluids?
Nanofluids are engineered suspensions of nanometer-sized solid particles in a base fluid. Suspending small solid particles in the energy transmission fluids can improve their thermal conductivity and provides an effective and innovative way to enhance their heat transfer characteristics significantly.
How nanofluids work?
Nanofluid refers to the dispersion of metal or non-metal nano-powder into traditional heat exchange media such as water, alcohol, and oil to prepare a uniform, stable and high thermal conductivity. The traditional heat exchange medium has a low thermal conductivity and has been unable to meet the growing demand for industrial engineering heat exchange. The thermal conductivity of some metal or non-metal nanoparticles is often hundreds of times higher than that of heat-conducting media. For example, common silicon carbide nanoparticles have a thermal conductivity of 170-270 W/m•K. The researchers found that if the nanoparticles can be uniformly and stably dispersed in the heat transfer medium, the thermal conductivity of the nanoparticles will be greatly improved.
If there is .03L of NaOH in a flask, how can a .12M solution of H2SO4 be used to determine the concentration of NaOH in the reaction?
The concentration of NaOH in the reaction can be determined using the Titration method.
The concentration of NaOH in the reaction can be determined by titration.
A burette if filled with the known concentration of H₂SO₄ and then titrated against the known volume of NaOH in a conical flask. An indicator is used in order to determine the end-point of the titration process. At the end-point of the titration, the volume of acid used is recorded.
Next, we will write the balanced chemical equation of the reaction.
The balanced chemical equation for the reaction is
2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O
This means 2 moles of NaOH is required to neutralize 1 mole of H₂SO₄
Now, we can determine the concentration of NaOH by using the titration formula.
[tex]\frac{C_{A}V_{A} }{C_{B}V_{B}} = \frac{n_{A}}{n_{B}}[/tex]
Where [tex]C_{A}[/tex] is the concentration of acid
[tex]V_{A}[/tex] is the volume of acid
[tex]C_{B}[/tex] is the concentration of base
[tex]V_{B}[/tex] is the volume of base
[tex]n_{A}[/tex] is the mole ratio of acid
[tex]n_{B}[/tex] is the mole ratio of base
Then, we put the respective parameters, including the volume of acid determined from the titration process, into the formula to determine the concentration of the NaOH.
Hence, the concentration of NaOH in the reaction can be determined using the Titration method.
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How many electrons does chlorine need to gain in order to be like Argon ?
- 2 electrons
- 3 electrons
- 1 electron
As part of an investigation into the strength of electrostatic forces between molecules of water, a student will measure the melting point temperature. Which part of the experimental design does this describe?(1 point)
determining the procedure
determining what data to collect
deciding on the appropriate equipment
deciding on the number of trials to perform
Which experimental design would be best to use in investigating the boiling points of water and ethanol?
Heat samples of water and ethanol in two separate beakers using a Bunsen burner. Measure the temperatures at which the samples boil using a thermometer. Record these temperatures as the boiling points.
Mix samples of water and ethanol in a beaker, then heat using a Bunsen burner. Measure the temperature at which the sample boils using a thermometer. Record this temperature as the boiling point.
Heat samples of water and ethanol in two separate beakers using a Bunsen burner. Measure the temperatures at which the samples boil using a thermometer. Conduct several trials and record the average temperatures as the boiling points.
Mix samples of water and ethanol in a beaker, then heat using a Bunsen burner. Measure the temperature at which the sample boils using a thermometer. Conduct several trials and record the average temperature as the boiling point.
Which change happens when a substance melts?(1 point)
The vibration of the molecules produces enough heat to weaken the forces of attraction between the molecules of the substance.
Heat energy overcomes the forces of attraction between the molecules of the substance, so the molecules can move more freely.
Heat energy forces the molecules of the substance farther apart until the rigid structure of the solid breaks.
The molecules of the substance move farther apart, which pulls on the intermolecular bonds between them.
Which change occurs to cause water to boil into steam?(1 point)
The addition of kinetic energy causes the motion of water molecules to overcome gravitational forces.
The addition of kinetic energy causes the motion of water molecules to overcome gravitational forces.
The removal of kinetic energy causes the motion of water molecules to overcome electrostatic forces.
The removal of thermal energy causes the motion of water molecules to overcome gravitational forces.
Answer:
1) B. determining what data to collect
2) C. Heat samples of water and ethanol in two separate beakers using a Bunsen burner. Measure the temperatures at which the samples boil using a thermometer. Conduct several trials and record the average temperatures as the boiling points.
3) B. Heat energy overcomes the forces of attraction between the molecules of the substance, so the molecules can move more freely.
4). The addition of thermal energy causes the motion of water molecules to overcome electrostatic forces.
Explanation:
I think these are the answers, i'll confirm when I finish the test.
In an experiment it is known what quantity has to measured, thus the measurement of melting point has been determining what data to collect. Thus, Option B is correct.
To investigate the boiling point of water and ethanol, the samples has to boiled at constant parameters and the data has been collected with several trials. Thus, option C is correct.
Melting has been described as the change of the solid to the liquid state. With melting, there has been heat energy higher than the force of attraction allowing the molecules to move freely. Thus, option B is correct.
The boiling has been the change in the water at liquid state to the gaseous state. With boiling there is thermal energy capable of increasing the motion of water molecules overcoming electrostatic force.
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Explain the verse below in your own words in a little summary.
Hebrews 11:7
God had warned Noah of the flood and directed him to build an ark. Noah had faith in God and began building.
Answer:
God Warned Noah for the Flood comindg to Earth to wash away all the bad people's lives and god also said get couple animals girls and boys then build an ark then bring your family and food there to then noah had a faith in god so he obey and start builind the ark in a top of a mountain
Explanation:
Hebrews 11:7
A block has 73 kg is being pushed and accelerated at rate of 10 m/s. what force is being applied to the block?
A-730 N
B-7.3 N
C-7300 N
D-730 Kg
Answer:
730 N
Explanation:
force =mass×acceleration
force= 73kg × 10 m/s
f=730N
Heart, 5 stars, and Brainiest if right! Answer needed ASAP PLEASE!What type of forces do not change the motion of an object?
A. Acceleration forces
B. Balanced forces
C. Inertia forces
D. Unbalanced forces
Answer:
unbalanced force
Explanation:
pls mark me brainliest
Answer:
B. balanced forces
Explanation:
the motion of an object will not change if the forces pushing or pulling the object are balanced
Van der Waals bonds initiate
a) Between non-metals
b) Within ionic binds
c) Between metals
d) With H-bond
e) All of the above
I think e no
I am giving you hint
Draw the Lewis Structure for C2F4. b. Total RED's c. Nonbonding RED's d. Electron-Pair Geometry e. Molecular Shape f. Is it Polar, Nonpolar or Ionic
The molecule C2F4 has a trigonal planar molecular and electron pair geometry.
The shape of a molecule is dependent on the number of electron pairs that surround the central atom in the molecule. In the molecule C2F4, there are two central carbon atoms.
Each of the central carbon atoms have a trigonal planar molecular and electron pair geometry. C2F4 is a symmetrical molecule so it is nonpolar and has a zero dipole moment.
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what is the result of collisions of particles with an object? *
A. pressure on the object
B. pressure away from the object
C. the object gets lighter
D. the object gets heavier
Answer:
Particle collisions cause pressure.
Explanation:
The fast motion of gas particles gives them a relatively large amount of kinetic energy. Recall that kinetic energy is the energy that an object possesses because of its motion. The particles of a gas move in straight-line motion until they collide with another particle or with one of the walls of its container.
Equation for the incomplete combustion of methanol
Answer:
The basis for incomplete combustion is that instead of carbon dioxide being produced alongside water, carbon monoxide and carbon is produced instead, the carbon being released as soot. That handily sets the products up for the equation.
And combustion is simply a reaction between a fuel, in this case, methanol and oxygen.
The chemical formula for methanol is CH3OH. Simply write the reactants and products as a chemical equation and balance it, and you have the equation.
Explanation:
According to Hebrews 11, what did Abraham believe God would do if Isaac was slain as a sacrifice?
Answer:
He thought he was going to bring Isaac back from the dead. They ended up sacrificing the donkey instead.
Which of the following describes a heterotroph?
Heterotrophs get their energy directly from the sun.
Heterotrophs conduct photosynthesis.
Heterotrophs can create their own food.
Heterotrophs cannot create their own food.
heterotrophs cannot create their own food and rely on others for food
Which molecule does not obey the Octate rule of valence electrons .
BeCl2
FeCl2
CuCl2
ZnCl2
Explanation:
Which molecule does not obey the Octate rule of valence electrons .
BeCl2
FeCl2
CuCl2
ZnCl2
→BeCl2
Explaination:
BeCl2 violates the octet rule because the boron should be in a suitable valence state such that it binds to 3 chlorines. However, in this molecule boron is associated with six electrons.
Answer:
BeCl2
Explanation:
hope Its useful for you
[tex] \\ \\ [/tex]
kk
Select True or False: The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol. Bloom's Level: Understand
True, the entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.
The third law of thermodynamics states that, the entropy of a system approaches a constant value as the temperature of the system approaches absolute zero.
The entropy of any perfectly ordered, crystalline substance at absolute zero temperature is zero. That is, the entropy of a pure, perfect crystalline substance at 0 K is 0 J/K.
Thus, we can conclude that the given statement is true. The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.
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Which are the two key factors that affect the rate of weathering of rocks?
Select 2.
A Climate
B Rock Type
C Bedrock
Answer:
A and B.
Explanation:
Climate:
High temperatures and greater rainfall increase the rate of chemical weathering. Lower temperatures can break rocks to by freezing water inside of a rock cracks. When it freezes it expands the water and forces the crack of the rock to expand.
Rock Type:
Certain types of rock are very resistant to weathering. Igneous rocks, especially intrusive igneous rocks such as granite, weather slowly because it is hard for water to penetrate them. Other types of rock, such as limestone, are easily weathered because they dissolve in weak acids.
Safety considerations
• Sodium Hydroxide (please insert one statement of caution from MSDS)
Answer:
d took the test
Explanation:
In each of the combinations, predict the more electronegative element based on its position on the
periodic table. Then look up the actual electronegativities. Circle the reaction pair that should
actually caust a reaction.
More
Combination Combination electronegative
A
B
element based on
position on table
Ba + Fe2-
Ba?- + Fe
Actual
Actual
electronegativity electronegativity
of element of element
a)
Ba =
Fe=
b)
)
Sn + Hg
Sn- + Hg
Sn =
Hg =
c)
)
Na + Mg2+
Na + Mg
Na=
Mg =
=
Zn + CO2-
Zn?- + Co
Zn =
Co=
c)
)
Na + Mg2+
Na + Mg
Na=
Mg =
=
Zn + CO2-
Zn?- + Co
Zn =
Co=
You have a block of an unknown metal. Which properties would be most helpful in determining what it is? If it could be
PLEASE HELP WILL GIVE BRAINLIEST
Answer:
Explanation:
Gravity pulls the balls down the ramp, and the force of gravity is bigger on larger-mass objects. The extra force on the bigger ball means that it has more energy when it gets to the bottom of the ramp and consequently travels more before stopping.
A 4.0 L balloon has a pressure of 406 kPa. When the pressure increases to 2,030 kPa, what is the volume? *
0.4 L
0.8 L
0.2 L
1 L
The new volume when pressure increases to 2,030 kPa is 0.8L
BOYLE'S LAW:
The new volume of a gas can be calculated using Boyle's law equation:
P1V1 = P2V2
Where;
P1 = initial pressure (kPa)P2 = final pressure (kPa)V1 = initial volume (L)V2 = final volume (L)According to this question, a 4.0 L balloon has a pressure of 406 kPa. When the pressure increases to 2,030 kPa, the volume is calculated as:
406 × 4 = 2030 × V2
1624 = 2030V2
V2 = 1624 ÷ 2030
V2 = 0.8L
Therefore, the new volume when pressure increases to 2,030 kPa is 0.8L.
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