Answer:
ΔH = -110.5kJ
Explanation:
It is possible to obtain enthalpy of combustion of a particular reaction by the algebraic sum of similar reactions (Hess's law). Using:
1. C(s) + O₂(g) → CO₂(g) ΔH₁ = -393.5kJ
2. CO(g) + 1/2O₂(g) → CO₂(g) ΔH₂ = -283.0kJ
The sum of 1 -2 gives:
C(s) + O₂(g) + CO₂(g) → CO₂(g) + CO(g) + 1/2O₂(g)
C(s) + 1/2O₂(g) → CO(g) ΔH = -393.5kJ - (-283.0kJ) =
ΔH = -110.5kJWhich of the following best describes the material that makes us the mantle?
Answer:
A- a rigid solid
Explanation:
The Earths mantle is mainly made up of rock and rocks are rigid and are solid.
Why do atoms become larger as you move down a group?
O The numbers of energy levels increase.
O Electron shielding increases.
O The decrease in ionization energy.
O The mass of the atom increases.
Explanation:
option C is the correct answer of this question
Using VSEPR theory which of the following would be the correct shape for nitrogen trifluoride?
Answer:
trigonal pyramidal
Explanation:
In NF3, the nitrogen atom is sp3 hybridized. Now we must remember that according to the VSEPR theory, the number of electron pairs in the valence shell of the central atom in a molecule determines its shape.
Here, the nitrogen atom is the central atom and its outermost shell is surrounded by four electron pairs - one lone pair and three bond pairs. This means that it has a tetrahedral electron pair geometry.
However, due to the lone pair, the three fluorine atoms are arranged in a trigonal pyramidal geometry. Hence the correct shape of the molecule is trigonal pyramidal.
How many moles are in 7.18x10^24 ions of mg
Answer:
11.93 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{7.18 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 11.92691...[/tex]
We have the final answer as
11.93 molesHope this helps you
MULTIPLE CHOICE QUESTION
Gain or Lose
Magnesium (Mg) has 2 valence electrons. Will
the Mg atom gain or lose electrons to form an
ion?
• Elements > 4 valance e-
gain e-
• Elements < 4 valance e-
lose e-
Neither
Lose
Gain
Please help me answer this first question.
Answer:
I think it would be 9 moles.
Scientists were studying three different embryos to determine their relationship to humans. The notes about each embryo are shown in the chart. Based on the information, what can you determine?
Answer:
Species A and C are related to humans.
Explanation:
got it right on edge.
Answer:A. Species And C are related to humans
Explanation: In the embryo humans and other Species have gill slits, and a tail. Vestigesof tales grew and non-human ancestors. On rare occasions, aremnant of the tail through and embryological development, although this tale of course has no function. An embryos splits are found in the boreals of all vertebrates because they share a common ancestors with fish and which structures first
The function of a specific enzyme is mostly determined by its
Answer:
What does the shape of an enzyme determine? The shape of the enzyme determines which chemical reaction it will speed up. -The region on an enzyme that the substrate fits into. ... The active site of an enzyme only fits one type of substrate molecule.
Explanation:
10 points
10. What is the correct order of your blood vessels from largest to
smallest?
a. veins arteries, capillaries
b. capillaries, veins, areteries
c. arteries, veins, capillaries
d. none of the above
Dr. Bert Vogelstein and his partners study the causes of cancer. In 2017, they published a study of 32 types of cancer. The study concluded that most cancer cases are caused by DNA replication errors. In fact, 66% of the cancer cases they studied were caused by random DNA replication errors. Environmental factors such as diet, sunburns, and smoking caused 29% of the cancers. The last 5% of cancers in the study were caused by inherited factors.
Briefly describe the steps of DNA replication and point out one place in the code where an error can occur.
Answer:
Error or mistakes during DNA replication is accountable for two-thirds or 66% of the cancer cases. These random and unpredictable errors called mutations that occur during the division of a cell as an error in copying of DNA.
DNA replication has three main steps:
Opening and separation of DNA strands of a helix - carried by an enzyme known as helicase that breaks the hydrogen bonds between nitrogenous bases of the helix of DNA.
The priming of the template strand - DNA primase helps RNA primers to bind to both strands at 3' end as soon as it separated
strat assembling the segments of new DNA on strands called elongation of the strands with help DNA polymerase I and after forming new strands the termination of the replication.
Errors or mistakes can occasionally take place if DNA polymerase inserts a wrong base during elongation of the strands.
Explain Nuclear Fusion vs Gravity a.Gravity pushes outward and Nuclear fusion pushes inward. b.Both gravity and nuclear fusion push inward. c.Both gravity and nuclear fusion push outward. d.Nuclear fusion pushes outward, and gravity pushes inward.
Answer:
d.
Explanation:
The term known as "Nuclear Fusion" is a very important concept in chemistry and it is studied mostly under the topic or aspect of Chemistry known as or called radioactivity. Nuclear Fusion is the kind of reaction in which two or more atomic nucleus combines to for bigger ones.
There is a saying that there is no life without nuclear fusion because it is the reaction that causes the stars to have light.
Option 'd' is correct. This is what happens in stars in order for light to be produced that is the inward movement of gravity and the outward movement of nuclear fusion.
What is happening to the total amount of water on earth?
Olt is increasing.
Olt is decreasing.
Otisn't changing.
Answer:
It isnt changing
Explanation:
It stays basically the same becuase it is considered a constant
HELP please it’s due soon
Answer:
1. D
2. A
3. B
4. A
5. BB
Explanation:
1d. 50%
2a. 29.5
3b. increasing
4a. decreasing
5b. waxing
Which product of photosynthesis is mainly considered to be waste for plants, although some is used during respiration?
A. oxygen
B. carbon dioxide
C. glucose
D. energy
Answer:
A. Oxygen
Explanation:
A is the only one that makes sense because plants take in carbon dioxide, use glucose for food, and use energy to photosynthesize, and the only answer they don't use is A (oxygen) because they only produce it but not use it
We have a photon with the wavelength of 605 nm. What is the frequency of this
photon?
Answer:
Explanation:
Speed of light = Wavelength x Frequency.
605 nm x Frequency = 3x10^8 m/s
6.05 x 10^-7 m x Frequency = 3x10^8 m/s
Frequency = 4.96 x 10^14 Hz
Answer:
ν=4.96x10^14 Hz
Explanation:
c=λν
λ=wavelength
ν=frequency
in this problem:
c=3x10^8
λ=605x10^-9
so ν=c/λ
v=(3x10^8)/(605x10^-9)
v=4.96x10^14
please give thanks :)
x-rays had a frequency of about 3x10^18 determine it's wavelength (in nm) and energy per photon
Answer:
E = 19.89×10⁻¹⁶ J
λ = 1×10⁻¹ nm
Explanation:
Given data:
Frequency of xray = 3×10¹⁸ Hz
Wavelength of xray = ?
Energy of xray = ?
Solution:
speed of wave = wavelength × frequency
speed = 3×10⁸ m/s
3×10⁸ m/s = λ ×3×10¹⁸ s⁻¹
λ = 3×10⁸ m/s / 3×10¹⁸ s⁻¹
λ = 1×10⁻¹⁰m
m to nm:
λ = 1×10⁻¹⁰m×10⁹
λ = 1×10⁻¹ nm
Energy of x-ray:
E = h.f
h = plancks constant = 6.63×10⁻³⁴ Js
by putting values,
E = 6.63×10⁻³⁴ Js ×3×10¹⁸ s⁻ ¹
E = 19.89×10⁻¹⁶ J
A saturated aqueous solution of sucrose contains 200 grams of sucrose and 100 grams of water. Which is the solvent: sucrose or water?
Answer:
The solvent is water
Explanation:
The solvent is the substance in the mixture that is able to dissolve the other substances. The solvent is usually the liquid.
In the problem is said: "A saturated aqueous solution", that means the solution is made by a solute that is in excess (Sucrose) dissolved in the solvent (Water).
The solvent is water
How does the concept of action- reaction apply to the human body?
Answer:
The physical body of human work accosting to Action-Reaction law.
Explanation:
The rule of action-reaction state that an equivalent and reverse reaction occurs with any action. If one entity imposes force on a second entity, the second responds by exerting an equivalent force on first entity in the same direction.
Fission U235 can produce what?
A Krypton
B Strontium
C Barium
D Xeonon
E All of the above
Answer:
A. krypton
Explanation:
give me brainly
Which phrase justifies why the theory of evolution is a theory and not a law?
1. Describes the relationship between an organism and its environment
2. Makes accurate predictions based on only a small amount of empirical evidence
3. Explains diversity based on the principle of natural selection
4. Cannot be modified with the discovery of new evidence
Answer:
2. Makes accurate predictions based on only a small amount of empirical evidence
Explanation:
For a phrase or scientific finding to be considered a law, there has to be clear evidence and facts to support that specific finding. In the case of the evolution theory, the evidence is not clear enough to make it a law
Answer:
2. Makes accurate predictions based on only a small amount of empirical evidence
Explanation:
5. Where are red blood cells produced?
10 points
O a. in the heart
b. in the blood vessels
c. in bone marrow
O d. in the plasma
Answer:
C
Explanation:
it's produced in the bone marrow
What is the electron configuration for Ti (titanium)?
Explanation:
Titanium is an element found in the d-block group on the periodic table. It is a transition element.
To write the electronic configuration of an element, we must know the number of electrons in them;
In a titanium atom, we have 22 electrons;
Shell notation = 2 8 10 2
Orbital notation = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d² 4s²
Answer: [Ar]4s^2 3d^2
Explanation:
The recessive allele tends to (blank) when it's in the presence of the dominant allele.
Answer:
The recessive allele tends to be masked when it's in the presence of the dominant allele.
Explanation:
Many of our traits are affected by our genes. From each of our parents, we receive one copy of every gene. These copies are called alleles.
There are different types of relationships that can occur between alleles. One of them is called dominance. This occurs when one allele masks the other, not allowing its effect to be expressed. The allele that masks the other is called the dominant allele (A), and the masked one is called the recessive allele (a). This means that an individual needs to have only one dominant allele in order for its effect to be expressed (AA or Aa). The effect of the recessive allele will be expressed only when an individual has both recessive alleles (aa).
What is the percent composition for dihydrogen monoxide?
Answer:
I think the answer is 11.190% :)
Explanation:
Hope this helps <3
Lithium is a metal,chlorine is a non metal,so LiCl would be a ______bond
a.Metallic
b.Covalent
c.Ionic
Please answer for me.
Answer:
54.5%
Explanation:
The percentage composition of oxygen in C₆H₈O₆ can be obtained as follow:
Molar mass of C₆H₈O₆ = (12×6) + (8×1) + (16×6)
= 72 + 8 + 96
= 176 g/mol
Next, there are 6 oxygen atoms in C₆H₈O₆. Therefore the mass of oxygen in C₆H₈O₆ is:
Mass of Oxygen = 16 × 6 = 96 g
Finally, we shall determine the percentage composition of oxygen in C₆H₈O₆ as follow:
Percentage of oxygen =
Mass of Oxygen/mass of C₆H₈O₆ × 100
Percentage of oxygen = 96 / 176 × 100
Percentage of oxygen = 54.5%
Thus, the percentage composition of oxygen in C₆H₈O₆ is 54.5%.
For an object to remain at rest, which of the following must be true?
The forces on it are balanced
There is no friction
Gravity does not act on it
The object has no mass
Answer: I believe that it is that the forces are balanced.
Explanation:
Acids containing polyatomic ions are named according to the name of the anion. true or false
Answer:
true
Explanation:
Names for such acids consist of the prefix “hydro-“, the first syllable of the anion, and the suffix “-ic”. Complex acid compounds have oxygen in them. For an acid with a polyatomic ion, the suffix “-ate” from the ion is replaced with “-ic.”
5. Which part makes up most of our blood vessels?
O a capillaries
Ob veins
O carteries
d. blood
Answer: a capillaries
Explanation:
0.500 L of a gas is collected at 2911 MM and 0°C. What will the volume be at STP?
Answer:
V₂ = 1.92 L
Explanation:
Given data:
Initial volume = 0.500 L
Initial pressure =2911 mmHg (2911/760 = 3.83 atm)
Initial temperature = 0 °C (0 +273 = 273 K)
Final temperature = 273 K
Final volume = ?
Final pressure = 1 atm
Solution:
Formula:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
by putting values,
V₂ = P₁V₁ T₂/ T₁ P₂
V₂ = 3.83 atm × 0.500 L × 273 K / 273 K × 1 atm
V₂ = 522.795 atm .L. K / 273 K.atm
V₂ = 1.92 L