Answer:As temperature increases, reactions take place. Generally, higher temperatures mean faster reaction rates; as molecules move about more quickly, reactant molecules are more likely to interact, forming products.
Explanation:
Answer:
Endothermic and Exothermic Reactions
Many familiar chemical reactions, such as the burning of coal, rusting and exploding gunpowder, give off heat; chemists call these reactions exothermic. Because reactions liberate heat, they increase the ambient temperature.
Deforestation, intensive agriculture, and drought can result in a condition called
A) urban sprawl
B) land reclamation
C) pollution
D) desertification
Answer:
D
Explanation:
Human activities that contribute to desertification include the expansion and intensive use of agricultural lands, poor irrigation practices, deforestation, and overgrazing. ... Some meteorologists and soil scientists measure the impacts and length of a drought to determine if it is an example of desertification.
Which of the following is a true statement about wind erosion?
Most wind erosion happens in the Arctic.
Most wind erosion happens in deserts, beaches, and plowed fields.
Most wind erosion happens only on top of mountains.
Most wind erosion happens in areas with tropical climate.
Answer :
B. Most wind erosion happens in deserts, beaches, and plowed fields.
what does the suffix -ine mean in the word heroine?
example :
the silent movie heroine faced danger from an evil villain.
a. female
b. many
c. young
d. great
Answer:
Female
Explanation:
Answer: A. Female.
Explanation: The word 'heroine' means a female or a woman that is admired and looked upon for her courage, bravery, and noble qualities.
Arrange the following substances from the lowest to highest normal boiling point: CaO, O2, H2, H2CO, H2O.
Answer:
The answer is CH4<CH3OCH3<CH4O<CaCO3
Explanation:
The order of the lowest to highest normal boiling point:
H₂ < O₂ < H₂CO₃ < H₂O < CaO
What is the boiling point?The boiling point is the temperature at which the vapor pressure of the liquid becomes equal to the atmospheric pressure. At this temperature, the liquid phase is changed into a vapor phase.
The boiling point is the temperature point at which the material transforms into the gas phase in the liquid phase. The Celsius scale was created on the basis of the ice or water melting point and the liquid water or vapor boiling point. Each substance consists its own boiling point.
The boiling point of Calcium oxide is 2850° C as it has a strong force of attraction between the ions. The boiling point of water as we already know is equal to 100° C.
The boiling point of the oxygen gas is -183°C and the boiling point of the hydrogen gas is - 252.8°C. The boiling point of carbonic acid is 333.6°C.
Therefore, CaO has the highest, and hydrogen gas has the lowest normal boiling point among the given compounds.
Learn more about Boiling point, here
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What is true if a liquid and a gas are in equilibrium?
O A Liquid molecules forming a gas and gas molecules forming a
liquid are equal in number.
O B. Liquid molecules are continually forming to replace escaping gas
molecules.
C. The liquid molecules stay liquid, and the gas molecules stay gas.
O D. The number of liquid molecules and the number of gas molecules
vary
Answer:
A - Liquid molecules forming a gas and gas molecules forming a
liquid are equal in number.
Explanation:
A P E X
Determine the Oxidation number of the indicated element in each of the following substances: Mn in KMnO4 S in SO2 C in COCl2 P in PF4 O in K2O2
Answer:
1. Mn = +7
2. S = +4
3. C = +4
4. P = +4
5. O = -1
Explanation:
The oxidation number of each element in a compound is as follows:
1. Mn in KMnO4
KMnO4 = 0
Where; K = +1, O = -2, Mn = x
+1 + x -2(4) = 0
1 + x - 8 = 0
x - 7 = 0
x = +7
2. S in SO2
SO2 = 0
Where; S = x, O = -2
x + -2(2) = 0
x - 4 = 0
x = +4
3. C in COCl2
COCl2 = 0
Where; C = x, O = -2, Cl = -1
x + -2 + -1(2) = 0
x + -2 + -2 = 0
x -2 - 2 = 0
x - 4 = 0
x = +4
4. P in PF4
PF4 = 0
Where; P = x, F = -1
x + -1 (4) = 0
x - 4 = 0
x = +4
5. O in K2O2
K2O2 = 0
Where; K = +1, O = x
+1(2) + x(2) = 0
2 + 2x = 0
-2x = 2
x = -1
if an exothermic reaction takes place in an insulated container at the end of the reaction the temperature of the content of the container will
Answer:
Remain the same.
Explanation:
The reaction of the temperature of the content of the container will remain the same because no heat energy is transfer from the container to the external environment due to insulating material of the container. Insulators are poor conductor of heat and electricity so the container is unable to absorb the heat energy produced during a chemical reaction and all energy of the product remain the same.
CHEMISTRY HELP! Lewis structure rules
Please help, is this correct?
Answer:
it is the one below that. NO, because it debt net the octet rule
can u pls help me with this question
In Universe L, recently discovered by an intrepid team of chemists who also happen to have studied interdimensional travel, quantum mechanics works just as it does in our universe, except that there are three d orbitals instead of the usual number we observe here. Use these facts to write the ground-state electron configurations of the second and third elements in the first transition series in Universe.
Answer:
Second element(Titanium); [Ar] 3d2 4s2
Third element(Vanadium):Ar 3d3 4s2
Explanation:
Given that there are only three d orbitals in universe L instead of five, the electronic configuration of the second and third elements in the first transition series will now look thus;
Second element(Titanium); [Ar] 3d2 4s2
Third transition element(Vanadium):Ar 3d3 4s2
Hence, the electronic configuration of Titanium and Vanadium in universe L is just the same as what it is on earth.
HURRY
Fill in the blank -
metals like to _ electrons to form ionic bonds
It is a hot summer day. Your dog, Spot, is lying in the shade, panting. The water content in the dog's blood gets low. Spot gets up
to find________ because he is responding to the internal stimulus of_______
A)
food; hunger
B)
water; thirst
C)
his bed; sleepiness
D)
shade; high temperatures
How does the environment play an important role in creating petrified fossils?
Cold environment prevents fossils from being created.
The right conditions need to be present in order for fossilization to occur.
All fossils are created in the same type of environment.
Hot environment prevents fossils from being created.
How does the environment play an important role in creating petrified fossils?
Answer:The right conditions need to be present in order for fossilization to occur.
Drier environments, such as land, are more susceptible to the effects of erosion and so it is more difficult to preserve the organism before it decays.
#CARRYONLEARNING #STUDYWELLA friend is calculating the energy of reaction for a combustion reaction using bond energies, and the calculations are returning a positive for ?H. What, if anything, has your friend done incorrectly?
A. He or She used the wrong table of bond energies
B. Nothing, a combustion reaction should have a positive ?H
C. He or she may have subtracted the reactants from the products
D. Bond energies don’t apply to combustion reactants and should not be used.
Answer:
He or She used the wrong table of bond energies
Explanation:
We know that we obtain the energy of a reaction also known as the enthalpy of reaction from the formula; ΔHo(reaction) = sum of the bond energies of bonds being broken - sum of the bond energies of the bonds being formed.
Combustion is an exothermic reaction for which the value of ΔH is expected to the negative. If ΔH is not negative, then the calculation was not properly done and the wrong values of bond energy were probably used.
Answer:
He or she may have subtracted the bond energies for the reactants from the products.
Explanation:
Select the correct answer.
Which phrase correctly describes temperature?
A.
average rotational kinetic energy of the particles in an object
B.
average energy of the particles in an object
C.
average translational kinetic energy of the particles in an object
D.
all energy possessed by the particles in an object
Answer:
C. average transnational kinetic energy of the particles in an object.
Explanation:
Temperature measures the average kinetic energy of the particles in a substance. Thermal energy measures the total kinetic energy of the particles in a substance. The greater the motion of particles, the higher a substance's temperature and thermal energy. Therefore we could say that the average kinetic energy of a gas particle is directly proportional to the temperature. Hence an increase in temperature increases the speed in which the gas molecules move. All gases at a given temperature have the same average kinetic energy.Describe how to use a transfer pipet to deliver 10.00 mL of liquid by placing the steps in the correct order.
This question is incomplete, the complete question is;
Describe how to use a transfer pipet to deliver 10.00 mL of liquid by placing the following steps in the correct order;
- Replace the bulb with your index finger and wipe excess liquid off the outside of the pipette.
- Place the tip of the pipette against the side of the beaker and drain the liquid from the pipette until the bottom of the meniscus reaches the calibration mark.
- Transfer the pipette to the receiving vessel.
- Drain the pipette by gravity while holding the tip against the side of the receiving vessel.
- Use a rubber bulb to suck liquid up past the 10.00 ml calibration mark.
- Suck up a third volume of liquid past the 10.00 ml calibration mark.
- Discard the first two pipette volumes of the liquid to rinse the pipette.
Answer:
- Use a rubber bulb to suck liquid up past the 10.00 ml calibration mark.
- Discard the first two pipette volumes of the liquid to rinse the pipette.
- Suck up a third volume of liquid past the 10.00 ml calibration mark.
- Replace the bulb with your index finger and wipe excess liquid off the outside of the pipette.
- Place the tip of the pipette against the side of the beaker and drain the liquid from the pipette until the bottom of the meniscus reaches the calibration mark.
- Transfer the pipette to the receiving vessel.
- Drain the pipette by gravity while holding the tip against the side of the receiving vessel.
Explanation:
First of all, We use a suction device to suck up liquid into pipet. Then we will fill the pipet up to the 10 mL marks and will discard the initial two volumes of liquid and will take a final third volume. We will replace the bulb with index finger and will drain it by placing the tip of pipet at the wall of beaker and drain the liquid.
Arranged in the following steps correctly;
- Use a rubber bulb to suck liquid up past the 10.00 ml calibration mark.
- Discard the first two pipette volumes of the liquid to rinse the pipette.
- Suck up a third volume of liquid past the 10.00 ml calibration mark.
- Replace the bulb with your index finger and wipe excess liquid off the outside of the pipette.
- Place the tip of the pipette against the side of the beaker and drain the liquid from the pipette until the bottom of the meniscus reaches the calibration mark.
- Transfer the pipette to the receiving vessel.
- Drain the pipette by gravity while holding the tip against the side of the receiving vessel.
Suppose 128 radioactive atoms have a half-life of 15 seconds. Approximately how many radioactive atoms will be left after 60 seconds
Answer:
8 electrons
Explanation:
Number of atoms = 128
Half life = 15 s
After each half life, the number of atoms reduces by half. So we need to determine how many half lives are in 60s.
Number of half lives = 60s / 15s = 4
After the first life;
Number of electrons left = 128 / 2 = 64
After the second life;
Number of electrons left = 64 / 2 = 32
After the third half life;
Number of electrons left = 32 / 2 = 16
After the fourth half life;
Number of electrons left = 16 / 2 = 8
Answer:
C. 8
Explanation:
correct on gizmo; After one half-life (15 seconds), about 64 radioactive atoms will remain, half of the original 128. After a second half-life passes (30 seconds total), about 32 radioactive atoms will remain, half of 64. After a third half-life passes (45 seconds), about 16 radioactive atoms will remain. A time of 60 seconds represents four half-lives, so about 8 radioactive atoms will remain.
Balance the equation.
P + 02 --> P4O10
Answer:
4P + 5O₂ —> P₄O₁₀
Explanation:
From the question given above, we obtained:
P + O₂ —> P₄O₁₀
The above equation can be balance as illustrated below:
P + O₂ —> P₄O₁₀
There are 4 atoms of P on the right side and 1 atom on the left side. It can be balance by 4 in front of P as shown below:
4P + O₂ —> P₄O₁₀
There are 10 atoms of O on the right side and 2 atoms on the left side. It can be balance by putting 5 in front of O₂ as shown below:
4P + 5O₂ —> P₄O₁₀
Now the equation is balanced.
How does an objects speed affect its kinetic energy?
CHEMISTRY HELP!! due in 10 minutes! :(
Answer:
Yes, because it match the octet rule!!
It is double bond lewis structure of ch2s!!
Explanation:
which element is the least reactive? Neon, Chlorine, Gallium or Tin
0.2 mol of hydrocarbons undergo complete combustion to give 35.2 of carbon dioxide and 14.4g of water as the only product. What is the molecular formula of hydrocarbon
Answer:
[tex]\rm C_4 H_8[/tex].
Explanation:
Look up the relative atomic mass of [tex]\rm C[/tex], [tex]\rm H[/tex], and [tex]\rm O[/tex] on a modern periodic table:
[tex]\rm C[/tex]: [tex]12.011[/tex].[tex]\rm H[/tex]: [tex]1.008[/tex].[tex]\rm O[/tex]: [tex]15.999[/tex].Calculate the molecular mass of [tex]\rm CO_2[/tex] and [tex]\rm H_2O[/tex]:
[tex]M(\mathrm{CO_2}) = 12.011 + 2 \times 15.999 = 44.009\; \rm g \cdot mol^{-1}[/tex];
[tex]M(\mathrm{H_2O}) = 2 \times 1.008 + 15.999 = 18.015\; \rm g \cdot mol^{-1}[/tex].
Given the mass [tex]m[/tex] of [tex]\rm CO_2[/tex] and [tex]\rm H_2O[/tex] produced, calculate the number of moles of molecules that were produced:
[tex]\displaystyle n(\mathrm{CO_2}) = \frac{m(\mathrm{CO_2})}{M(\mathrm{CO_2})} \approx 0.80\; \rm mol[/tex];
[tex]\displaystyle n(\mathrm{H_2O}) = \frac{m(\mathrm{H_2O})}{M(\mathrm{H_2O})} \approx 0.80\; \rm mol[/tex].
Calculate the number of moles of [tex]\rm C[/tex] atoms and [tex]\rm H[/tex] atoms in these [tex]\rm CO_2[/tex] and [tex]\rm H_2O[/tex] molecules.
Each [tex]\rm CO_2[/tex] molecule contains one [tex]\rm C[/tex] atom. Therefore, that [tex]0.80\; \rm mol[/tex] of [tex]\rm CO_2\![/tex] contains [tex]0.80\; \rm mol\![/tex] of [tex]\rm C\![/tex] atoms.Each [tex]\rm H_2O[/tex] molecule contains two [tex]\rm H[/tex] atoms. Therefore, that [tex]0.80\; \rm mol[/tex] of [tex]\rm H_2O\![/tex] contains [tex]2 \times 0.80\; \rm mol = 1.60\; \rm mol[/tex] of [tex]\rm H\![/tex] atoms.The combustion reaction here include two reactants: the hydrocarbon and [tex]\rm O_2[/tex].
As the name suggests, hydrocarbons contain only [tex]\rm C[/tex] atoms and [tex]\rm H[/tex] atoms. On the other hand, [tex]\rm O_2[/tex] contains only [tex]\rm O[/tex] atoms.
Therefore, all the [tex]\rm C[/tex] and [tex]\rm H[/tex] atoms in those [tex]\rm CO_2[/tex] and [tex]\rm H_2O[/tex] molecules are from the unknown hydrocarbon. (With a similar logic, all the [tex]\rm O[/tex] atoms in those combustion products are from [tex]\rm O_2[/tex].)
In other words, that [tex]0.20\; \rm mol[/tex] of this unknown hydrocarbon molecules contains:
[tex]0.80\; \rm mol[/tex] of [tex]\rm C[/tex] atoms, and [tex]1.60\; \rm mol[/tex] of [tex]\rm H[/tex] atoms.Hence, each of these hydrocarbon molecules would contain [tex](0.80\; \rm mol) / (0.20\; \rm mol) = 4[/tex] carbon atoms and [tex](1.60\; \rm mol) / (0.20\; \rm mol) = 8[/tex] hydrogen atoms.
The molecular formula of this hydrocarbon would be [tex]\rm C_{4} H_{8}[/tex].
Write a balanced half-reaction for the reduction of gaseous nitrogen N2 to aqueous hydrazine N2H4 in acidic aqueous solution. Be sure to add physical state symbols where appropriate.
Answer:
Explanation:
N₂ (g ) + 4H⁺( aq ) + 4e⁻ = N₂H₄ ( aq )
H⁺ ion comes from acidic medium . 4 positive charge on proton is balanced by 4 electron to make left hand side neutral because right hand side is neutral .
How many liters of oxygen are necessary for the combustion of 425 g of sulfur, assuming that the reaction occurs at STP
Answer:
V = 296.6 liters of oxygen.
Explanation:
The reaction of combustion of sulfur is:
O₂(g) + S(s) → SO₂(g) (1)
To find the volume of the oxygen we need to use the Ideal Gas Law:
[tex] V = \frac{n_{O}RT}{P} [/tex] (2)
Where:
V: is the volume
[tex]n_{O}[/tex]: is the number of moles of oxygen
R: is the gas constant = 0.082 L*atm/(K*mol)
T: is the temperature = 273 K (at STP)
P: is the pressure = 1 atm (at STP)
So we need to find the number of moles of oxygen that reacts with sulfur:
[tex]n_{S} = \frac{m}{M}[/tex]
Where:
[tex]n_{S}[/tex]: is the number of moles of sulfur
m: is the mass of sulfur = 425 g
M: is the molar mass of sulfur = 32.065 g/mol
[tex]n_{S}=\frac{m}{M} =\frac{425 g}{32.065 g/mol} = 13.25 moles[/tex]
From reaction (1) we have that 1 mol of O₂ reacts with 1 mol of S, hence the number of moles of oxygen is:
[tex] n_{S} = n_{O} = 13.25 moles [/tex]
Finally, the volume of oxygen is (equation (2)):
[tex]V = \frac{13.25 moles*0.082 L*atm/(K*mol)*273 K}{1 atm} = 296.6 L[/tex]
Therefore, are necessary 296.6 liters of oxygen for the combustion of sulfur.
I hope it helps you!
The diagram shows salt dissolved in water. What does it show about water molecules
and chloride ions?
+
Chloride
Oxygen
Hydrogen 4
Sodium
Answer:
that they all dissolved went on watef
Please help me 17 points!
Answer:
A dam: 3
solar cells: 2
food: 1
a rocket: 1
Answer:
1: yes
Explanation:
blank is the total disappearance of all members of a species.
Answer:
Extinction
Explanation:
When a species becomes extinct, every last specimen has died out
When an endothermic chemical reaction (the system) occurs inside a calorimeter containing water (the surroundings) and no heat escapes from the calorimeter, which of the following statements is true?
a. Heat flows from the system to the surroundings and the temperature of the water increases.
b. Heat flows from the surroundings to the system and the temperature of the water decreases.
c. Heat flows from the system to the surroundings and the temperature of the water decreases.
d. Heat flows from the surroundings to the system and the temperature of the water increases.
Answer:
b. Heat flows from the surroundings to the system and the temperature of the water decreases.
Explanation:
The laws of thermodynamics lets us know that energy is neither created nor destroyed but can be converted from one form to another. Also, energy transfer does accompany chemical reactions in the form of heat.
For an endothermic reaction, heat is absorbed by the system from the surroundings. This leads to a drop in the temperature of the surroundings as energy is removed.
This implies that the water temperature decreases.
How many moles are in 64 grams of Ca(NO3
)2
Answer:
0.39 moles
Explanation:
Given mass of calcium nitrate =64gram
Molar mass of calcium nitrate = 164 gram
No of moles = given mass/ molar mass
No of moles = 64/164
= 0.39 moles
Use the drop-down menus to identify the parts of DNA.
Label A:
Label B:
please help.