Answer:
CH4 + 2O2 --> CO2 2H2O, Combustion Reaction
Explanation:
Which substance is an element that is composed of molecules?
A. water (H2O)
B. methane (CH4)
C. hydrogen (H2)
D. helium (He)
Answer:
the answer is hydrogen which is B
The substance is an element that is considerably composed of molecules known as hydrogen (H2). Thus, the correct option for this question is C.
What is a Chemical element?A chemical element may be defined as a species of an atom that remarkably bears a specific number of sub-atomic particles in its structure. These elements are not further decomposed into smaller components in a chemical reaction.
H2 is also known as molecular hydrogen. It forms when two hydrogen atoms are significantly bonded to one another in order to give rise to a molecule. Water is not an element, it is a molecule. While methane is a chemical compound that possesses a chemical formula CH4. Helium (He) is a chemical element only.
Therefore, hydrogen is an element that is composed of molecules. Thus, the correct option for this question is C.
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calculate the number of each atom in 2.5 gram of caco3
Answer:
[tex]2.5\; \rm g[/tex] of [tex]\rm CaCO_{3}[/tex] would contain:
Approximately [tex]1.5 \times 10^{22}[/tex] calcium atoms (approximately [tex]0.025\; \rm mol[/tex],)Approximately [tex]1.5 \times 10^{22}[/tex] carbon atoms (approximately [tex]0.025\; \rm mol[/tex],) andApproximately [tex]4.5 \times 10^{22}[/tex] oxygen atoms (approximately [tex]0.075\; \rm mol[/tex].)Explanation:
Look up the Avogadro constant: [tex]N_{\rm A} \approx 6.022 \times 10^{23}\; \rm mol^{-1}[/tex].
For example, "[tex]1\; \rm mol[/tex] of carbon atoms" would contain [tex]N_{\rm A}[/tex] carbon atoms (approximately [tex]6.022\times 10^{23}[/tex]) by definition.
Look up the relative atomic mass of carbon, calcium, and oxygen on a modern periodic table:
Calcium: [tex]40.078[/tex].Carbon: [tex]12.011[/tex].Oxygen: [tex]15.999[/tex].In other words, the mass of [tex]1\; \rm mol[/tex] of calcium atoms would be [tex]40.078\; \rm g[/tex]. The mass of [tex]1\; \rm mol\![/tex] of carbon atoms would be [tex]12.011\; \rm g[/tex], and the mass of [tex]1\; \rm mol \!\![/tex] of oxygen atoms would be [tex]15.999\; \rm g[/tex].
As the formula [tex]\rm CaCO_{3}[/tex] suggests, every formula unit of this ionic compound includes one calcium atom, one carbon atom, and three oxygen atoms. The formula mass of [tex]\rm CaCO_{3}\![/tex] would give the mass of every mole of [tex]\rm CaCO_{3}\!\![/tex] formula units.
Calculate the formula mass of [tex]\rm CaCO_{3}[/tex] from the relative atomic mass data:
[tex]\begin{aligned} & M({\rm CaCO_{3}}) \\ =\; & 40.078\; \rm g \cdot mol^{-1} \\ & + 12.011\; \rm g \cdot mol^{-1} \\ & + 3 \times (15.999\; \rm g \cdot mol^{-1}) \\ =\; & 100.086\; \rm g \cdot mol^{-1}\end{aligned}[/tex].
Calculate the number of [tex]\rm CaCO_{3}[/tex] formula units in that [tex]2.5\; \rm g[/tex] of this compound:
[tex]\begin{aligned}& n({\rm CaCO_{3}}) \\ =\; & \frac{m({\rm CaCO_{3}})}{M({\rm CaCO_{3}})} \\ =\; & \frac{2.5\; \rm g}{100.086\; \rm g \cdot mol^{-1}} \\ \approx\; & 0.025\; \rm mol\end{aligned}[/tex].
In other words, [tex]2.5\; \rm g[/tex] of [tex]\rm CaCO_{3}[/tex] would contain approximately [tex]0.025\; \rm mol[/tex] [tex]\rm CaCO_{3}\![/tex] formula units.
Again, there are one calcium atom, one carbon atom, and one oxygen atom in every [tex]\rm CaCO_{3}[/tex] formula unit. That approximately [tex]0.025\; \rm mol[/tex] [tex]\rm CaCO_{3}\![/tex] formula units would thus contain:
Approximately [tex]1 \times 0.025\; \rm mol = 0.025\; \rm mol[/tex] calcium atoms, Approximately [tex]1 \times 0.025\; \rm mol = 0.025\; \rm mol[/tex] carbon atoms, andApproximately [tex]3 \times 0.025\; \rm mol = 0.075\; \rm mol[/tex] oxygen atoms.Make use of the Avogadro constant to convert the numbers.
For example, the number of calcium atoms in that approximately [tex]0.025\; \rm mol[/tex] of calcium atoms would be:
[tex]\begin{aligned} & N({\text{calcium}) \\ = \; & n({\text{calcium}) \cdot N_{\rm A} \\ \approx \; & 0.025\; \rm mol \times 6.022\times 10^{23} \cdot mol^{-1} \\ \approx \; & 1.5 \times 10^{22} \end{aligned}[/tex].
Likewise, the number of carbon atoms in that approximately [tex]0.025\; \rm mol[/tex] of carbon atoms would be:
[tex]\begin{aligned} & N({\text{carbon}) \\ = \; & n({\text{carbon}) \cdot N_{\rm A} \\ \approx \; & 0.025\; \rm mol \times 6.022\times 10^{23} \cdot mol^{-1} \\ \approx \; & 1.5 \times 10^{22} \end{aligned}[/tex].
The number of oxygen atoms in that approximately [tex]0.075\; \rm mol[/tex] of oxygen atoms would be:
[tex]\begin{aligned} & N({\text{oxygen}) \\ = \; & n({\text{oxygen}) \cdot N_{\rm A} \\ \approx \; & 0.075\; \rm mol \times 6.022\times 10^{23} \cdot mol^{-1} \\ \approx \; & 4.5 \times 10^{22} \end{aligned}[/tex].
If you wanted to increase the speed of
vaporization, you could
A. put the substance in the freezer.
B. place a lid on the substance.
C. heat the substance to the boiling point.
D. cool the substance to the freezing point.
>
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Answer:
C. heat the substance to the boiling point.
Answer:
heat the substance
Explanation:
what is x if x - 2 =0
Answer:
x-2 = 0
x = 2
hope this was help full
4. In KCl, how are the valence electrons distributed?
O A. The electrons are shared between many K and Cl ions, creating a "sea of electrons."
B. The electrons are transferred from K to CI.
O c. The electrons are equally shared between K and Cl, forming a covalent bond.
D. The electrons are unequally shared between K and Cl, forming a polar covalent bond.
Answer:
Since KCl is an ionic compound, there is transfer of electrons from K to Cl. Thus right answer should be (B)
KCl is a chemical called potassium chloride that has been known to be an ionic compound. The valence electrons ion KCl gets transferred from K to Cl ion. Thus, option B is correct.
What is an ionic bond?An ionic bond is said to be a type of chemical bond that involves the gain and loss of the electron in the valence shell of the atom species. It involves the bond formation between the ions.
The ions with opposite charges, carrying a positive and negative are said to bond by accepting and donating their electrons to achieve the noble-gas (electronic) configuration.
In KCl, potassium has more electrons and can donate it to chlorine species as the latter lacks electrons. Chlorine accepts electrons and in the process acquires a negative charge, whereas potassium gains a positive charge.
Therefore, option B. the KCl involves ionic bonds by transferring electrons.
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What is the final temperature of water given an initial temperature of 28 ˚C, a mass of 7 g, and heat (q) of 184 J (Specific Heat of water = 4.184 )?
Answer:34.28 Degree celcius
Explanation:The heat given is equal to the change in temperature multiplied by the mass and the specific heat capacity
This gives the equation:Q=mc∆T
Where Q=184,m=7, specific heat capacity=4.184,∆T=X-28,
But ∆T=Final temperature (T'')-Initial temperature (T')
Therefore the equation becomes
184=7×4.184(X-28)
Solving the remaining linear equation gives you X as 34.28°C
If an inverse relationship exist between x and y, and k = 200, which of the following would be points on the graph?
-(200,0.1)
-(100, 0.2)
-(400, 0.5)
-(800, 0.4)
Answer:
The answer is (400, 0.5)
Element X forms the ion X22- What is the formula of the covalent compound X forms with chlorine?
A XCI
B XCl2
C XCl3
D XCl4
Answer:
the answer is mostly option a)XCl
Explanation:
Which of these statements best describes how mining of minerals helps solve societal problems?
A) By reducing pollution in air.
B) By removing contaminants from the soil.
C) By improving the condition of groundwater.
D) By providing jobs to the unemployed people
Answer:
d cause it is
Explanation:
If I have a bottle of compound X at a pressure of 45 atm and temperature of 100 °C, what will happen if I raise the temperature to 400 °C?*
Answer:
55/350
Explanation:
because the answer is in the middle of 50and 400
what is joules? plz help
What is the correct clases for this drugs
Promethazine
heelp me please
Answer:
MedlinePlus Drugs Information
Explanation:
Promethazine is in a class of medication called phenothiazines
When 0.60 mol NH 3 is decomposed in a 1 Liter flask at 850 K, the equilibrium concentration of NH3 is measured as 0.12 M. Given that ammonia decomposes according to the reaction
2 NH3(g) ⇌ N2(g) + 3 H2(g),
what is Kc for the reaction?
a. 0.16
b. 12.00
c. 1.44
d. 6.22
e. 0.75
Answer:
in a 1 Liter flask at 850 K, the equilibrium concentration of NH3 is measured as 0.12 M. Given that ammonia decomposes according to the reaction
2 NH3(g) ⇌ N2(g) + 3 H2(g),
what is Kc for the reaction?
a. 0.16
b. 12.00
c. 1.44
d. 6.22
e. 0.75
The response is 12.00 (b). Using the equation Kc = [N2][H2]3/[NH3]2, we can find the equilibrium constant Kc for the reaction 2 NH3(g) N2(g) + 3 H2(g).
What is the equilibrium concentration ?In this instance, the capacity of the flask is 1 litre, and the equilibrium concentration of NH3 is 0.12 M. Therefore, using the reaction's stoichiometry, it is possible to determine the equilibrium concentrations of N2 and H2.
Since 2 moles of NH3 break down into 1 mole of N2 and 3 moles of H2, the equilibrium concentrations of N2 and H2 are 0.06 M and 0.18 M, respectively. As a result, the equilibrium constant Kc = [N2][H2]3/[NH3]2 = (0.06)(0.18)3/0.122 = 12.00 may be computed.
Therefore, b. 12.00 is the right response. You should be aware that the equilibrium constant Kc is a value that is temperature-dependent and is only applicable at the specified temperature. As a result, Kc will have a varied value depending on the temperature. The temperature in this instance is 850 K, and the Kc value is 12.00.
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2. An Isotope of technetium, mixed with sulphur and colloidally dispersed in water, is frequentyused in diagnosing various medical conditions because it is readily taken up by various tissues Prior to excretion. Explain why this important
mixture is not a true solution.
Answer:
This is not a true solution because the colloidal dispersion is not completely homogeneous, and it does not have uniform properties throughout.
Explanation:
hope i helped
Which of the following statements is incorrect for the reaction of 1,3- butadiene with a substituted alkene CH2=CHX when X is a nitro group?
Answer:
hugsvsbsbbsnjsjsnsbsbbzbd
2. Based on the following balanced equation:
2 NH3 + 202 N2O + 3 H2O
a. How many moles of O2 are required to react completely with 3.00 moles of NH3?
1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00
b. How many moles of H20 are produced after complete reaction of 3.00 moles of NH3?
1.00
1.50 2.00 2.50 3.00
3.50 4.00 4.50 5.00
c. How many moles of N O are produced after complete reaction of 3.00 moles of NH3?
1.00 1.50 2.00 2.50 3.00
3.50
4.00 4.50 500
To do this, just take the given miles and multiply it with the ratio of molecules in the chemical equation to get your answer.
Which list only includes terms that describe oxygen gas, O2?
A. element, molecule, pure substance
B. atom, compound, molecule
C. atom, element, molecule
D. compound, molecule, pure substance
Answer:
d
Explanation:
it just makes alot of sense and you got this
Oxygen is a gas that belongs to the chalcogen family and is a reactive non-metal. It is an element, molecule, or pure substance. Thus, option A is correct.
What is a pure substance?A pure substance is defined as a substance that cannot be physically separated into its constituent particles. They are known to have a definite and constant chemical composition. It can be a molecule, element, or compound.
An element is atomic species that cannot be broken into simple sub-particles by chemical processes. On the other hand, if an atomic element bonds to the same or different atom it forms a molecule.
Oxygen gas is an element composed of two atoms of oxygen and is a molecule as the two atoms are linked chemically. It is also a pure substance as it contains the same element.
Therefore, option A. oxygen gas is a pure substance, an element, and a molecule.
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what is the chemical formula of ( methane ) ??
[tex]\huge{ \color{violet}{ \boxed{ \color{hotpink}{Answer}}}}[/tex]
what is the chemical formula of ( methane ) ??
» CH4[tex] \: [/tex]
--⚘ Mishi ChaeYoon ⚘--Answer:
[tex]CH_4[/tex]
Explanation:
Methane is a chemical compound with the formula CH4. ( One atom of carbon and four atoms of hydrogen).
------------------------
OAmalOHopeO
------------------------
Convert 50 kilograms into grams.show your work
Answer:
50000 g
Explanation:
1 kilogram (kg) is equal to 1000 grams (g).
1 kg = 1000 g
The mass m in grams (g) is equal to the mass m in kilograms (kg) times 1000:
m(g) = m(kg) × 1000
Choose the best possible answer for Q.No. A, B, and C.
The following is an acid-base reaction between sulfuric acid and aluminum hydroxide. Use the provided molar masses to answer the questions below:
molar
mass
3 H2SO4
+
2 Al(OH)3
⟶
Al2(SO4)3
+
6 H2O
g/mol
98.08
78.00
342.15
18.02
Note: You need to upload the documents for A, B, and C to show your work.
A. How many moles of sulfuric acid would be required to form 65.21g of Water?
moles of H2SO4 = ________
[ Select ]
B. How many grams of Aluminum Sulfate could be formed if 197.0g aluminum hydroxide reacts with sulfuric acid?
mass of Al2(SO4)3 = ________
[ Select ]
C. To determine the concentration of a sulfuric acid sample, a titration is performed with the above reaction. What is the concentration of the sulfuric acid if a 15.00mL sample reached its titration endpoint with 29.26mL of 0.2855M Al(OH)3?
Molarity of H2SO4 = ________
[ Select ]
Answer:
c i think
Explanation:
HELP PLEASE WILL MARK BRAINLIEST!!!!!!!
Answer:
Precise
Explanation:
hope it helps!!!!!!!!
which function of lysosomes is carried out by vacuoles in plant cells
Answer:
Lysosomes are predominantly found in eukaryotic animal cells and are responsible for breaking down cellular debris
Explanation:
Identify whether the solubility of Ag_2CrO_4 will increase or decrease by adding the following agents.
a. Na2CrO4
b. HCl
c. NH3
The Coca- cola is diluted and reacted with molybdate/metavanadate reagent before the %T is measured.
a. True
b. False
Answer:
true
Explanation:
I believe that is the correct answer (if right brainiest plz)
When salt dissolves completely into water, which term is used to describe the water?
Answer:
A salt that is dissolved in water is called a solute
Once you have dissolved the salt - you have a solution
The water is called the solvent
Explanation:
We have that When salt dissolves completely into water the water is called a Solvent
it is important to not that once the salt compound comes into water it breaks down the molecule apart the Na on one hand and the Cl on the other hand
Once the NaCl is dissolved in to the H_2O it is known as a solute of salt
And when When salt dissolves completely into water the water is called a Solvent
Therefore
When salt dissolves completely into water the water is called a Solvent
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Please help thank you (15 points)
Answer:
Jupiter.
Explanation:
Jupiter has the fastest axial rotation time (day) in the list of answers, based on the fact that its day is only 10 hours long.
HCl reacts with O2 as follows: 4HCl+O2→2Cl2+2H2O When 1.79 g of HCl reacts with 5.68 g of O2 , which statement applies?
the statements that are applicable are the ones that mention HCl being a limiting reactant, or the one that includes that the maximum amount of Cl gas that can be produced is 1.74g
Where did you put H an He? What are your reasoning for placement?
Answer:
On the placement of hydrogen and helium in the periodic system
H1=1
He2=2
A sealed reaction vessel initially contains 1.113×10-2 moles of water vapor and 1.490×10-2 moles of CO(g).
H20(g) +CO(g) <==> H2(g) + CO2(g)
After the above reaction has come to equilibrium, the vessel contains 8.326×10-3 moles of CO2(g).
What is the value of the equilibrium constant Kc of the reaction at the temperature of the vessel?
Answer:
Kc =[tex]\frac{[8.326x10-3]^{1} }{[1.113x10-2]^{1}[1.490x10-2]^{1} }[/tex]
Kc = 50.2059
Explanation:
1. Balance the equation
2. Use the Kc formula
Remember that pure substances, like H2 are not included on the Kc formula
The value of the equilibrium constant Kc of the reaction at the temperature of the vessel is 0.05.
Calculation,
The balanced chemical equation is given as,
[tex]2H_{2}O[/tex] + [tex]2CO[/tex] → [tex]2H_{2}[/tex] + [tex]2CO_{2}[/tex]
At t=0 1.113×[tex]10^{-2}[/tex] 1.490×[tex]10^{-2}[/tex] 0
At [tex]t=t_{eq}[/tex] 1.113×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex] 1.490×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex] 8.326×[tex]10^{-3}[/tex]
The number of moles of [tex]H_{2}O[/tex] at equilibrium = 1.113×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex]
The number of moles of [tex]CO[/tex] at equilibrium = 1.490×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex]
The number of moles of [tex]CO_{2}[/tex] at equilibrium = 8.326×[tex]10^{-3}[/tex]
What is equilibrium constant?Equilibrium constant is calculated bt ratio of product of concentration of reactant by product.
K = [tex][H_{2}O]^{2}[/tex]×[tex][CO]^{2}[/tex]/[tex][CO_{2}]^{2}[/tex]
K =( 1.113×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex] )∧2× (1.490×[tex]10^{-2}[/tex]-8.326×[tex]10^{-3}[/tex])∧2/(8.326×[tex]10^{-3}[/tex])∧2
K = 0.049 ≈ 0.05
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How many elements have properties of both metals and non-metals?
Answer:
The elements boron, silicon, germanium, arsenic, antimony, and tellurium separate the metals from the nonmetals in the periodic table. These elements, called metalloids or sometimes semimetals, exhibit properties characteristic of both metals and nonmetals.
Elements: Oxygen
