Answer:
a. KCl, c. BaCl2 and e. LiF.
Explanation:
Hello,
In this case, we can identify the ionic compounds by verifying the difference in the electronegativity between the bonding compounds when it is 1.7 or more (otherwise it is covalent) as shown below:
a. KCl: 3.0-0.9=2.1 -> Ionic.
b. C2H4: 2.5-2.1=0.4 -> Covalent.
c. BaCl2: 3.0-0.8=2.2 -> Ionic.
d. SiCl4: 3.0-1.8=1.2 -> Covalent.
e. LiF: 4.0-1.0=3.0 -> Ionic.
Therefore, ionic compounds are a. KCl, c. BaCl2 and e. LiF.
Regards.
why diamond has a high melting point
Explanation:
Each carbon atom is covalently bonded to four other carbon atoms in diamond. A lot of energy is needed to separate the atoms. This is because covalent bonds are strong. This is the reason why diamond has a high melting point.
1. Why is it important to know the names and appearance of lab equipment before doing laboratory work? 1. So you will score higher on the lab test. 2. So you quickly obtain your laboratory supplies before lab. 3. So you can follow the lab instructions clearly. 4. So you can make sure everything has been cleaned before beginning the lab procedure.
Answer:
1. because what if you do a incorrect ion? it would be all wrong! 2. you dont get it quickly because! you might get the wrong equipment. 4. yep! no food or drinks!
Explanation:
hope this helps ☻︎
A football field is supposed to be exactly 120yd long, including the end zones. How many inches is this?
Answer:
4320 inches
Explanation:
math
A football field is supposed to be exactly 120yd long, including the end zones is 4320 inches.
What are zones?Zones are defined as a space that is physically or artificially isolated from other spaces. There are numerous sorts and sizes of zones.
Zones are also defined as a region that is designated as having a specific average annual minimum temperature, which is important for many plants to survive.
There are four types of zones.
The intimate spaceThe personal spaceThe social spaceThe personal spaceThe Torrid Zone, Temperate Zone, and Frigid Zone are the three temperature-based regions of the Earth.
Planting zones are predetermined areas based on the types of plants that thrive there.
Thus, a football field is supposed to be exactly 120yd long, including the end zones is 4320 inches.
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Which of the changes are chemical changes?
In order to find the density of an object, Maria is trying to measure its volume. However, the object does not fit in the
tool she is using. To solve this problem, Maria decides to break apart the object.
Will Maria be able to find density following this method? Why or why not?
O Yes, if she measures the volume and mass of all the pieces of the object, she should be able to calculate density
O Yes, if she measures the volume and mass of one of the pieces of the object, she should be able to calculate
density.
O No, once the object is broken apart and the shape has been altered, it is not possible to calculate the volume of
the whole object to find density.
O No, once the object is broken apart and the shape has been altered, it is not possible to calculate the mass of the
object to find density.
Answer: She needs to divide the mass by the volume to find the density of the object.
Explanation:
When you calculate apercent recovery you may find sometimes that it islarger than 100%. Assuming this is NOT due to errors associated with zeroing the balance, subtracting the weight of the watch glass or weigh paper, or inaccuracies in the balance calibration, suggest a possible reason for this.
Answer:
Presence of impurities in the product.
Explanation:
Laboratory experience has shown that the percent yield obtained from a reaction may be greater than 100% if the product obtained from the reaction contains impurities that causes its mass to be greater than it actually would be if the product was pure.
A typical impurity that may be present in a product is the solvent used. This can be removed by evaporation of the solvent or by washing the product thoroughly.
Reaction of solid products with gases may also increase the percentage yield above 100%.
Which of the following would a chemist be most likely to study? A. what happens when a moving car comes to a stop B. what happens when iron rusts in the presence of water C. what happens when ice melts to form liquid water D. what happens when light reflects from a shiny surface
Answer:
B. what happens when iron rusts in the presence of water
Explanation:
Consider the interaction of two hydrogen ls atomic orbitals of the same phase. Which statements below is an incorrest description of this interaction? A) A sigma bonding molecular orbital is formed. B) The molecular orbital formed is lower in energy than a hydrogen 1s atomic orbital. C) The molecular orbital formed has a node between the atoms. D) The molecular orbital formed is cylindrically symmetric. E) A maximum of two electrons may occupy the molecular orbital formed.
Answer:
B) The molecular orbital formed is lower in energy than a hydrogen 1s atomic orbital.
Explanation:
When two atoms of hydrogen come close to each other , there is formation of molecular orbital . Due to overlap of 1 s orbital of one and 1 s orbital of another atom , two molecular orbitals are formed . One of these molecular orbital has energy less than 1 s atomic orbital . It is called 1 s sigma bonding molecular orbital . The other molecular orbital has energy more than 1 s atomic orbital . It is called antibonding molecular orbital . Two electrons occupy bonding sigma molecular orbital .
So , the statement that "the molecular orbital formed is lower in energy than a hydrogen 1s atomic orbital " is wrong .
How many protons and neutrons does iron-56 have? Question 10 options: 26 protons and 56 neutrons 26 protons and 26 neutrons 30 protons and 56 neutrons 26 protons and 30 neutrons
Answer:
Protons: 26
Neutrons: 30
Explanation:
what is the mass of an electron is
Answer:
the rest mass of an electron is 9.1093837915
Answer:
Fundamental properties. The invariant mass of an electron is approximately 9.109×10−31 kilograms, or 5.489×10−4 atomic mass units. On the basis of Einstein's principle of mass–energy equivalence, this mass corresponds to a rest energy of 0.511
Chocolate candy melting in your hand is what type of heat transfer
Ignore my writing, but I’m so confused on this. Please help me
Before this it was talking about sig figs, so I’m not sure if you’re supposed to use sig figs in this or not.
Explanation:
You are suppose to use sig figs.
5.
Which statement is false?
Chemistry explains many aspects of nature.
Knowledge of chemistry allows the public to make informed decisions.
How does heat conduction work in the metal brownie pan?
The heat from the oven heats up the metal pan, and the metal pan transfers the heat to the brownies.
What is heat conduction?Heat conduction is defined as the transfer of heat in an object from the area of hotter region to the area of cooler region through microscopic particles and movement of electrons within the body.
All the objects such as metal brownie pan that is capable of conducting heat is called the term thermal conductivity.
Examples of metals that are good conductors of heat include the following Gold, Silver, Copper, Aluminium, Iron.
Therefore, is can be concluded that the oven heats up the metal pan, and the metal pan transfers the heat to the brownies.
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Which is a symbol that represents SI units for temperature.
A. 'C
B. g
C. L
D. 'F
Answer:
A.'C
Explanation:
Please answer my question
Answer:
the answer would be a
Explanation:
You may want to reference (Page) Section 12.4 while completing this problem. Enter the balanced chemical equation for the complete combustion of each of the following hydrocarbons found in gasoline used to start a fire:________.
Part A. liquid nonane
Express your answer as a chemical equation including phases.
Part B. liquid isopentane (2-methylbutane)
Express your answer as a chemical equation including phases.
Part C. liquid 3-ethyltoluene
Express your answer as a chemical equation including phases.
Answer:
See explanation
Explanation:
In this question, we have to remember that in all combustion reactions we will have Oxygen as reactive ([tex]O_2[/tex]) and the products are Carbon dioxide ([tex]CO_2[/tex]) and Water ([tex]H_2O[/tex]). Additionally, for the states, we will have (l) for the liquid state and (g) for the gas state. So, we can analyze each reaction:
Part A.
The formula for nonane is [tex]C_9H_2_0[/tex], with this in mind we can write the combustion reaction:
[tex]C_9H_2_0_(_I_)~ +~ O_2~->~CO_2_(_g_)~ +~H_2O_(_g_) [/tex]
When we balance the reaction we will obtain:
[tex]C_9H_2_0_(_I_)~ +~14 O_2_(_g_)~->~9CO_2_(_g_)~ +~10H_2O_(_g_) [/tex]
Part B.
The formula for 2-methylbutane is [tex]C_5H_1_2[/tex], with this in mind we can write the combustion reaction:
[tex]C5H12_(_I_)~ +~O_2_(_g_)~->~CO_2_(_g_)~ +~H2O_(_g_) [/tex]
When we balance the reaction we will obtain:
[tex]C5H12_(_I_)~ +~8O_2_(_g_)~->~5 CO_2_(_g_)~ +~6 H2O_(_g_) [/tex]
Part C.
The formula for 3-ethyltoluene is [tex]C_9H_1_2[/tex], with this in mind we can write the combustion reaction:
[tex]C_9H_1_2_(_I_)~+~O_2_(_g_)~->~CO_2_(_g_)~+~H2O_(_g_)[/tex]
When we balance the reaction we will obtain:
[tex]C9H12_(_I_)~ +~12O_2_(_g_)~->~9CO_2_(_g_)~ +~6H2O_(_g_)[/tex]
See figure 1 for further explanations.
I hope it helps!
Is it true you will often have more control over the setting when photographing a pet versus a wild animal
Answer: Sí
Explanation: ya que una mascota es inofensiva, pero para fotografiar a un animal salvaje, debes esperar pacientemente el momento perfecto
Calculate the mass of sucrose necessary to make a 5% by mass sucrose solution if the solution contains 50.0 ml of distilled water. (Hint: the total mass of the solution is the mass of sucrose plus the mass of water.)
Answer:
2.6 g
Explanation:
Percent concentration = 5%
Volume of water = 50ml
Since 1ml of water = 1g of water
Mass of water= 50g
Let the mass of sucrose be x
Mass% = mass of solute/mass of solute + mass of solvent × 100
5= x/x+ 50 ×100
5/100 = x/x + 50
0.05 = x/x + 50
0.05(x + 50) = x
0.05x + 2.5 = x
2.5 = x - 0.05x
2.5 = 0.95x
x= 2.5/0.95
x=2.6 g
Calculate ΔHrxn for the following reaction:
5C(s)+6H2(g)→C5H12(l)5C(s)+6H2(g)→C5H12(l)
Use the following reactions and given ΔH values:
C5H12(l)+8O2(g)→ 5CO2(g)+6H2O(g) ΔH= -3505.8 kJ
C(s)+O2(g)→CO2(g) ΔH= -393.5 kJ
2H2(g)+O2(g)→ 2H2O(g) ΔH= -483.5 kJ
Answer:
ΔH = 87.8kJ
Explanation:
You can determine ΔH of a reaction from the sum of similar reactions (Hess's law). In the problem with the given ΔH:
1. C5H12(l)+8O2(g)→ 5CO2(g)+6H2O(g) ΔH= -3505.8 kJ
2. C(s)+O2(g)→CO2(g) ΔH= -393.5 kJ
3. 2H2(g)+O2(g)→ 2H2O(g) ΔH= -483.5 kJ
5 times 2. + 3 times 3:
5C(s) + 8O2(g) + 6H2(g) → 5CO2(g) + 6H2O(g)
ΔH= 5*(-393.5 kJ) + 3*(-483.5 kJ) = -3418kJ
Now, this reaction - 1:
5C(s)+6H2(g) → C5H12(l) ΔH= -3418kJ - (-3505.8kJ)
ΔH = 87.8kJ8. An example of an atom that has no charge is one that has
A. 2 protons, 2 electrons, and 1 neutron.
B. 3 protons, 2 electrons, and 1 neutron.
C. 1 proton, 2 electrons, and 3 neutrons.
D. 3 protons, 1 electron, and 3 neutrons.
Please help ASAP, thank you
Answer:
A. 2 protons, 2 electrons, and 1 neutron .
Answer:
A 2 protons, 2electrons,1 neutron
270kJ are needed to keep a 75 watt light bulb burning for 1 hour. How many kilocalories are needed to burn this light bulb for 3 hours?
Answer:
For 1 hour 75w light bulb requires 270 kj for burning
for 3 hours 75 w light bulb requires 270*3 = 810kj for burning
Explanation:
Calculate the PE of an object that has a mass of 2kg that is resting on a 6m table. HELP ME PLEASE I REALLY NEEEEED HELP!!!! 21 POINTS PLEASSEEEE
Answer:
Calculate the unknown variable in the equation for gravitational potential energy, where potential energy is equal to mass multiplied by gravity and height; PE = mgh. Calculate for different gravity of different enviornments - Earth, the Moon, Jupiter, or specify your own. Free online physics calculators, mechanics, energy, calculators.
Explanation:
Ocean water becomes colder; the density of ocean water increases or decreases?
Answer:
the density increases
Explanation:
Coz high temperature makes water less dense. As water gets warmer, its molecules spread out, so it becomes less dense. As it gets colder, it becomes denser
A 5.0g sample of MgCl2 may contain measurable amounts of other compounds as impurities. Which of the following quantities is (are) needed to determine that the sample is pure MgCl2 ?
Answer:
The mass of Mg and the mass of Cl in the sample
Explanation:
We have that the sample's is purity is simply the mass of Mg and the mass of Cl in the sample
From the Question we are told that
Mass of MgCl2 =5g
Therefore
What we need to determine that the sample's is purity is simply the mass of Mg and the mass of Cl in the sample because
the mass of MgCl should be equal to mass of Mg and mas of Cl
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The TV weather forecaster announces that one location has a 30% chance of rain tomorrow and a 35% chance of hail. What is the probability that it will rain or hail in this location?
Answer: 65%
Explanation:
When in probability and the outcome is mutually exclusive which means that either one or the other will happen then the probabilities of the events should be added up.
P(A or B) = P(A) + P(B)
P(Rain or Hail) = P(Rain) + P(Hail)
P(Rain or Hail) = 30% + 35%
P(Rain or Hail) = 65%
A protein has an isoelectric point (pI) of 9. Which of the following statements best describes the state of this protein in aqueous solution at pH 7?
A. The side chains of the protein's basic residues will be mostly uncharged
B. The side chains of the protein's acidic residues will be mostly protonated
C. The protein will have no net charge
D. The protein will have a net positive charge
E. The protein will have a net negative charge
Answer:
The correct option is D
Explanation:
From the question we are told that
The pH of the aqueous solution is [tex]pH = 7[/tex]
The isoelectric point is [tex]pl = 9[/tex]
From the data given we see that the
[tex]pH[/tex] is below [tex]pl[/tex]
So the protein will have a net positive charge
A protein has an isoelectric point (pI) of 9, the statement which best describes the state of this protein is that the protein will have a net positive charge.
What is isoelectric point?Isoelectric point of any susbatnce is the pH of the substance where net charge on that substance will be zero, i.e. no. of positive charged ions will equal to the number of negative charged ions.
In the question it is given that value of isoelectric point (pl) of protein is 9 and given value of pH is 7. It means that isoelectric point is higher that given pH so the protein molecule should bear a positive charge on it. If pH value is greater than pl value then molecule will bear a negative charge.
Hence option (D) is correct.
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PLEASE HELP WITH PAGE 1 FOR QUESTIONS 1, 2, 3 WITH THE GRAPHING THANK YOU.
Jade wants to measure the thickness of a copper wire. She wound the copper wire 30 times around a pencil and used a ruler to measure the length of the wound wire as shown in the figure.
Section of ruler is shown next to a pencil with a wire wound around it. The markings on the ruler are from zero to two centimeters. There are two small markings, one is between zero and one and the other is between one and two. The length of the entire wound wire starts at zero and goes to the small marking which is exactly between one and two.
Which of these is the most accurate thickness of the copper wire? (1 point)
0.001 cm
0.005 cm
0.01 cm
0.05 cm
Answer: 0.05
Explanation:Divide the length (1.5 cm) by the number of turns (30)
The direct proportion rule allows you to find that the correct answer for the result of the thickness of the copper wire is:
0.05 cm
Copper is a strong material with which the cross section is constant, therefore the copper wire has a constant thickness, which is why when making a full turn it advances the same amount
When Jade wound thirty times (n = 30) it has the same diameter each time, therefore with a direct rule of proportions we can find the thickness of the wire.
If in 30 laps we have 1.5 cm, in one lap we have?
[tex]x= 1 turn ( \frac{1.5 cm}{30 turn} )[/tex]
x = 0.05 cm
In conclusion using a direct rule of proportions we can that the correct answer for the result of the thickness of the copper wire is:
0.05 cm
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Which of the following statements does not correctly characterize the rate of evaporation of a liquid?
I. Increases with increasing temperature because molecules have higher kinetic energies.
II. Increases with increasing surface area of the liquid because more molecules are located at the 54. surface.
III. Increases with stronger intermolecular forces because molecules in the liquid repel each other more.
a. I only
b. IIl only II only
c. II and III only
d. I and II only
Answer:
d. I and II only
Explanation:
Evaporation is the breakaway of liquid molecules through the surface of a liquid, into the surrounding atmosphere in the form of a gas. Evaporation increases with temperature, since the molecules posses more kinetic energy to break through the liquid surface barrier at a higher temperature. Also, an increase in the surface area puts more of the molecules of the liquid close to the interface of the liquid and the surrounding atmosphere, increasing their chances of breaking away. An increase in the intermolecular forces between the molecules of the liquid will only decrease the rate of evaporation, since more energy will be required by the liquid molecules to break free from the bond between them and their neighboring molecules.
Measured value 28.7053 cm, which has six significant figures. Round the measurement to five significant figures
Answer:
28.705 cm
Explanation:
Hello,
In this case, for rounding the number to five significant figures we must "cut" it at 5 so we hide the 3, therefore it turns out:
28.705 cm.
Moreover, we must realize that since such 3 is less than five, we do not modify the previous five to six, case which would happen if that three has changed to five or more.
Regards.