Answer:
A chemical reaction that has a positive ΔH is said to be endothermic , while a chemical reaction that has a negative ΔH is said to be exothermic . What does it mean if the ΔH of a process is positive? It means that the system in which the chemical reaction is occurring is gaining energy.
please answer this questions soon
i will mark him or her brillient
Answer:
1)Or
d.Sublimation
2)
b.iodine is the solute and alcohol is solvent
3)
a.compostion of solute
Answer:
1) a) centrifugation
OR
b) sublimation
2) a) iodine is the solute and alcohol is solvent
3) a) concentration of soLute
6. 240J of electric energy flows into a certain light bulb every second, and some energy is transformed into
light energy while some 'waste' thermal energy is also generated. If 200J of thermal energy is generated each
second, what is the efficiency of this bulb? (Hint: Pay good attention to what energy values you've been
given, before you start plugging them into the efficiency formula.)
Looking for
Solution
Given
I
Relationship Formula
Answer:
don't know
Explanation:
try it your self
try it your self
try it your self
try it your self
try it your self
try it your self
1125 J of energy is used to heat 250 g of iron to 55 °C. The specific heat capacity of iron is 0.45 J/(g·°C).
What was the temperature of the iron before it was heated?
55 °C
55 °C
35 °C
35 °C
45 °C
45 °C
20 °C
Answer:
45 °C.
Explanation:
From the question given above, the following data were obtained:
Heat (Q) = 1125 J
Mass (M) = 250 g
Final temperature (T₂) = 55 °C
Specific heat capacity (C) = 0.45 J/gºC
Initial temperature (T₁) =?
The initial temperature of the iron can be obtained as illustrated below:
Q = MC(T₂ – T₁)
1125 = 250 × 0.45 (55 – T₁)
1125 = 112.5 (55 – T₁)
Divide both side by 112.5
1125/112.5 = 55 – T₁
10 = 55 – T₁
Collect like terms
10 – 55 = –T₁
–45 = –T₁
Multiply through by –1
45 = T₁
T₁ = 45 °C
Therefore, the initial temperature of the iron is 45 °C
list from soft to hard
List the following minerals in order from softest to hardest:
apatite, calcite, talc, quartz, diamond.
Calculate the amount of mole of iron produced from the reaction of 15.9 grams of iron oxide.
Fe2O3 + 3 H2 +2 Fe + 3 H2O
Answer:
0.19875
Explanation:
nFe2O3=0.099375
nFe=2nFe2O3=0.19875
Write the empirical formula for at least four ionic compounds that could be formed from the following ions: NO3, Pb^4+, NH4, SO4
Explanation:
here's the answer to your question
double arrow just mean that it's a reversible process, and the reaction can go back and forth.
0.2g of water represents how many mole?
Answer:
0.0111moles
Explanation:
as moles = mass/ mr(16+1+1)
so 0.2g / 18
gives you 0.111moles
hope this helps :)
(Q014) Silicates a. are classified on the basis of what kind of metals they contain. b. form through the evaporation of water. c. are a large category of minerals that includes the common minerals calcite and dolomite. d. have the silicon-oxygen tetrahedron as their structural unit.
Answer: d. have the silicon-oxygen tetrahedron as their structural unit.
Explanation:
Silicates are anions that have both Oxygen and Silicon as the basis of their structure. These two form a tetrahedron type structure that enable them to be useful for a whole lot of things.
Silicates are very abundant on Earth as they comprise around 95% of the Earth's crust as well as the upper mantle which explains why they are mostly found in igneous rocks.
What do the solid white and red balls in this model represent?
H
H— — О
A. Planets and
the Sun
B. Electrons
C. Molecules
D. Atoms
PREVIOUS
Answer:
C. Molecules
Explanation: Water is a compound that conatins molecules hydrogen and oxygen.
Answer: Atoms
Explanation:
10. As electrons move through the electron-transport chain,
they lose energy, which is used to form
A. NAD.
B. ADP
C. ATP.
D. GBP
Answer:
NAD
Explanation:
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Answer:
They lose energy which is used to form ATP
How does adding oxygen (O) to this reaction change the equilibrium?
2s02(g) + O2(g) = 2s03(8)
Answer:
The equilibrium shifts right to produce more SO3 molecules.
Explanation:
The equilibrium law states that when a system encounters a disturbance like a temperature, concentration, or pressure modifications, it will react to restore a new state of equilibrium.
Adding a reactant such as oxygen (O2) will shift the reaction in the direction of the product, on the basis of the equilibrium law. Therefore, the equilibrium will move toward the product side.
hii pls help me to balance the equation thanksss
Answer:
2H2S (g) + 3O2 (g) = 2H2O (l) + 2SO2 (g)
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
[tex]\boxed{\pmb{\green{\sf{2H_{2}S(g) + 3O_{2}(g)\dashrightarrow 2H _{2}O(l)+2SO_{2}(g)}}}}[/tex]
▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
The compound KOH is ________. insoluble, because all compounds containing K are insoluble insoluble, because all compounds containing OH- are in soluble soluble, because all compounds containing K are soluble soluble, because all compounds containing OH- are soluble insoluble, because KOH is insoluble
Answer:
soluble because all compounds containing K are soluble
Explanation:
Most metal hydroxides are insoluble. However, alkali metal hydroxides (such as KOH and NaOH) are very soluble.
In the case of KOH, the K cation is attracted to the electronegative oxygen on water. The OH anion is capable of hydrogen bonding to the water. (Notice how OH⁻ is simply the deprotonated form of water.)
The compound KOH is soluble insoluble, because all compounds containing K are insoluble insoluble, because all compounds containing OH- are in soluble soluble, because all compounds containing K are soluble soluble, because all compounds containing OH- are soluble insoluble, because KOH is insoluble
What are alkalis?Alkalis are bases which are soluble in water. The basic alkalis are as follows:
KOHNaOHCa(OH)2Mg(OH)2 is insoluble in water.
In conclusion, KOH is a soluble base
Learn more about alkalis:
https://brainly.com/question/25317545
What are the metals that can displace Iron(||) from a solution
What does it mean to view something from a frame reference
Answer:
In physics, a frame of reference, or reference frame, is a perspective that one uses to determine if an object is moving.
For example, when you see a ball roll down a street, you can tell the ball is moving because the frame of reference is the streets, whatever may be on the side of the roads, or the Earth
Stickleback fish are collected from a lake in Alaska. 600 from the sample are spineless, which is a recessive trait in the fish. 80 of the fish collected have spines. Calculate:
Answer:
Frequency of spinal trait in the population = 0.11
Explanation:
Given:
Total spineless trait = 600
Number of spinal trait = 80
Find:
Frequency of spinal trait in the population
Computation:
Total population = Total spineless trait + Number of spinal trait
Total population = 600 + 80
Total population = 680
Frequency of spinal trait in the population = Number of spinal trait / Total population
Frequency of spinal trait in the population = 80 / 680
Frequency of spinal trait in the population = 0.11
What volume of O2 is required to completely burn 15cm3 of pentane? Equation - C5H12 + O2 - CO2 + H2O.
Answer:
The volume of [tex]\rm O_2[/tex] required would be [tex]120\; \rm cm^{3}[/tex], assuming that both the pentane and the [tex]\rm O_2\![/tex] in this question are ideal gases and are under the same temperature and pressure.
Explanation:
Balance the equation for the reaction:
[tex]\rm ?\; C_{5}H_{12} + ?\; O_2 \to ?\; CO_{2} + ?\; H_{2}O[/tex].
Start by setting the coefficient of the molecule with the largest number of atoms to [tex]1[/tex].
In the combustion of alkanes (including pentane,) consider setting the coefficient of the alkane to [tex]1\![/tex].
[tex]\rm 1\; C_{5}H_{12} + ?\; O_2 \to ?\; CO_{2} + ?\; H_{2}O[/tex].
Number of carbon atoms among the reactants: [tex]5[/tex].
Number of hydrogen atoms among the products: [tex]12[/tex].
By the conservation of atoms, there would need to be the same number of carbon and hydrogen atoms (along with the oxygen atoms) among the products.
Hence, the coefficient of [tex]\rm CO_2[/tex] would be [tex]5[/tex] while the coefficient of [tex]\rm H_2O[/tex] would be [tex]12 / 2 = 6[/tex].
[tex]\rm 1\; C_{5}H_{12} + ?\; O_2 \to 5\; CO_{2} + 6\; H_{2}O[/tex].
There would be [tex]5 \times 2 + 6 \times 1 = 16[/tex] oxygen atoms among the products. Also by the conservation of atoms, there would be the same number of oxygen atoms among the reactants.
Hence, the coefficient of [tex]\rm O_2[/tex] would be [tex]16 / 2 = 8[/tex].
[tex]\rm 1\; C_{5}H_{12} + 8\; O_2 \to 5\; CO_{2} + 6\; H_{2}O[/tex].
The ratio between the coefficient of [tex]\rm O_2[/tex] and [tex]\rm C_{5}H_{12}[/tex] in the balanced equation is:
[tex]\displaystyle \frac{n({\rm O_2})}{n({\rm C_{5}H_{12}})} = \frac{8}{1} = 8[/tex].
In other words, it would take eight [tex]\rm O_2[/tex] molecules to react with one [tex]\rm C_{5}H_{12}[/tex] molecule.
Assume that both [tex]\rm O_2[/tex] and [tex]\rm C_{5}H_{12}[/tex] are ideal gases. Under the same temperature and pressure, the volume of the two gases would be proportional to the number of molecules in each gas:
[tex]\displaystyle \frac{V({\rm O_2})}{V({\rm C_{5}H_{12}})} = \frac{n({\rm O_2})}{n({\rm C_{5}H_{12}})} = \frac{8}{1} = 8[/tex].
In other words, it would take [tex]8\; \rm cm^{3}[/tex] of [tex]\rm O_2[/tex] to react with [tex]1\; \rm cm^{3}[/tex] of [tex]\rm C_{5}H_{12}[/tex] under these assumptions. It would then take [tex]8 \times 15\; \rm cm^{3} = 120\; \rm cm^{3}[/tex] of [tex]\rm O_2\![/tex] to react with [tex]15\; \rm cm^{3}\![/tex] of [tex]\rm C_{5}H_{12}\![/tex].
Oxide of nitrogen that is acidic
Answer:
Nitrogen oxides are used in the production of nitric acid, lacquers, dyes, and other chemicals. Nitrogen oxides are used in rocket fuels, in the nitrification of organic chemicals, and in the manufacture of explosives.
Explanation:
The dehydration of a secondary alcohol, like cyclohexanol, is a mechanism that occurs Choose... . First, the alcohol is protonated to Choose... , creating Choose... intermediate. Then, a Choose... is removed, moving the electrons from that bond to make a Choose... bond.
Answer:
Mechanism
explanation:
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The atomic mass of calcium is calculated by adding the mass (amount) of
A) Protons and Electrons
B) Protons and Neutons
C) Electrons and Neutons
D) Protons and Protons
Answer:
B. Protons and Neutrons
Answer:
Option"B" is correct.
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The hydroboration of an alkene occurs in ___________ which places the boron of the borane on the ___________ carbon of the double bond. The oxidizing agent then acts as a nucleophile, attacking the electrophilic _____________ and resulting in the placement of a hydroxyl group on the attached carbon. Thus, the major product of the hydroboration oxidation reaction ______ follow Markovnikov's rule.
Answer: The hydroboration of an alkene occurs in TWO CONCERTED STEP which places the boron of the borane on the LESS SUBSTITUTED carbon of the double bond. The oxidizing agent then acts as a nucleophile, attacking the electrophilic BORON and resulting in the placement of a hydroxyl group on the attached carbon. Thus, the major product of the hydroboration oxidation reaction DOES NOT follow Markovnikov's rule.
Explanation:
Hydroboration is defined as the process which allows boron to attain the octet structure. This involves a two steps pathway which leads to the production of alcohol.
--> The first step: this involves the initiation of the addittion of borane to the alkene and this proceeds as a concerted reaction because bond breaking and bond formation occurs at the same time.
--> The second step: this involves the addition of boron which DOES NOT follow Markovnikov's rule( that is, Anti Markovnikov addition of Boron). This is so because the boron adds to the less substituted carbon of the alkene, which then places the hydrogen on the more substituted carbon.
Note: The Markovnikov rule in organic chemistry states that in alkene addition reactions, the electron-rich component of the reagent adds to the carbon atom with fewer hydrogen atoms bonded to it, while the electron-deficient component adds to the carbon atom with more hydrogen atoms bonded to it.
The process of diffusion can be described as: Movement of water from the area of high concentration of solute to the area of low concentration of solute. Movement of solute from the area of low concentration of solute to the area of high concentration of solute. Movement of water from the area of low concentration of solute to the area of high concentration of solute. Movement of solute from the area of high concentration of solute to the area of low concentration of solute.
Answer:
Movement of water from the area of high concentration of solute to the area of low concentration of solute.
Explanation:
Diffusion can be defined as the movement of gas molecules from a region of high concentration to a region of lower concentration until an equilibrium is attained or reached. This mixing of gas molecules in the liquid or gaseous state is due to their kinetic energy of random motion i.e without requiring bulk motion.
This ultimately implies that, diffusion is a phenomenon through which gas molecules in either a gaseous or liquid state spread out in response to a concentration gradient, which is simply the difference in concentration of the gases across a space.
During diffusion, molecules move from areas of high concentration to areas of low concentration. Also, diffusion does not require energy to move molecules.
Hence, the process of diffusion can be described as movement of water from the area of high concentration of solute to the area of low concentration of solute.
A solute can be defined as a substance that is typically dissolved in a liquid solvent such as water, coffee, tea, etc., to produce a solution.
Which of the following are held together by nonpolar covalent bonds?
The Periodic Table
A. Atoms of phosphorus (P) and chlorine (CI)
B. Atoms of chlorine (CI)
C. Atoms of chlorine (CI) and magnesium (Mg)
D. Atoms of magnesium (Mg)
Answer:
Answer: Atoms of chlorine (CI) and magnesium (Mg)
Answer: Atoms of chlorine (CI) and magnesium (Mg)is your answer
What is the mass, in grams, of one mole of any substance known as?
ОА.
atomic mass
OB.
molar mass
O C.
molecular weight
OD.
atomic number
Answer:
I think it's answer would be A
Temperature is measured in degrees C whereas heat is measured in
J
m
t
q
Answer:
J
Explanation:
Heat is measured in Joules (J)
Why doesn’t the KHP concentration have to be exactly 0.100M? Explain using complete sentences.
Answer:
The answer is in the explanation.
Explanation:
The KHP is an acid used as standard in titrations to find concentration of bases as NaOH.
The reaction that explain this use is:
KHP + NaOH → KNaP + H2O
where 1 mole of KHP reacts per mole of NaOH
That means, at equivalence point of a titration in which titrant is NaOH, the moles of KHP = Moles of NaOH added
With the moles of KHP = Moles of NaOH and the volume used by titrant we can find the molar concentration of NaOH.
The moles of KHP are obtained from the volume and the concentration as follows:
Volume(L)*Concentration (Molarity,M) = moles of KHP
If the concentration is more or less than 0.100M, the moles will be higher or lower. For that reason, we need to know the concentration of KHP but is not necessary to be 0.100M.
What happens when you rub a plastic ruler and bring it closer to the tissue bits
Answer:
rubbing the ruler transfers electrons from the clothe to the ruler now the ruler has excess electrons and it is negatively charged... electrons will move away from the ruler leaving a positive charge on the tissue near the ruler so they attach
I hope this helps
which statement best describes the polarity of the molecule Sil4
a. it is polar, because the bond polarities add together in a tetrahedral molecule
b. It is non-polar, because the bond polarities cancel each other out in a tetrahedral molecule
c. it is non-polar, because the bonds between silicon (si) and iodine (I) are not polar
d. it is polar, because the bond polarities add together in a trigonal-planar molecule
please help I will mark as brainliest........
Name 2 materials that will ferment when added to water and mixed together at about 20°c.
Answer:
vegetables and salt
Explanation:
The ideal temperature for fermenting vegetables is between 18⁰-22⁰C. Within this range, the bacteria do their best work, giving high levels of lactic acid. The naturally occurring bacteria on fruits and vegetables is called lactobacillus. These bacteria convert the sugar to lactic acid, which is what gives that characteristic tangy/sour taste.
Please help with the Volume one
Answer:
im a just achild
Explanation:
Answer:
c
Explanation:
0.5dm³
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