Answer: Electrons are taken up by [tex]PbO_2[/tex] and they are lost by [tex]HCl[/tex]
Explanation:
Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously. It is also called the reaction where the exchange of electrons takes place.
An oxidation reaction is defined as the reaction in which a chemical species loses electrons takes place. In this reaction, the oxidation state of a substance gets increased.
A reduction reaction is defined as the reaction in which a chemical species gains electrons takes place. In this reaction, the oxidation state of a substance gets reduced.
For the given chemical reaction:
[tex]PbO_2+4HCl\rightarrow PbCl_2+Cl_2+2H_2O[/tex]
The half-reactions for this redox rection follows:
Oxidation half-reaction: [tex]2HCl\rightarrow ClO_2 + 2e^-[/tex]
Reduction half-reaction: [tex]PbO_2+2e^-\rightarrow PbCl_2[/tex]
Hence, electrons are taken up by [tex]PbO_2[/tex] and they are lost by [tex]HCl[/tex]
light energy travels in
Light energy travels in the form of waves.
The table below shows some characteristics of three different types of muscles
Answer: Type A are cardiac muscles Type B are skeletal muscles, and Type C are smooth muscles.
Explanation: sub to technoblade :P
Hydration of alkynes gives good yields of single compounds only with symmetrical or terminal alkynes. Draw the major organic product(s) formed when 3-methylcyclodecyne undergoes hydration in the presence of HgSO4 and H2SO4.
Answer:
Following are the solution to the given choice:
Explanation:
Hex-2-yne is just not alkyne symmetric, therefore two things respectively hexan-3-one and hexan-2-one are to be given.
The attached file it displayed the response along with the mechanism, please find the.
Calculate the mass of 100.0 mL of a substance whose density is 19.32 kg/L. Express your answer in kilograms using the correct number of significant figures. Do not enter your answer using scientific notation.
Answer:
1.932 kg
Explanation:
First we convert 100.0 mL to L:
100.0 mL / 1000 = 0.1000 LThen we calculate the mass of the substance, using the definition of density:
Density = mass / volumemass = density * volume19.32 kg/L * 0.1000 L = 1.932 kgAs the multiplication involves two numbers of 4 significant figures each, the answer needs to have 4 significants figures as well.
In which substance are molecules moving the fastest? The options are, a. Solid water (ice) b. Liquid water c. Water vapor (gas)
Answer:
The answer is C
Explanation:
The more space the molecules have the faster they will move, solid doesn't allow movement at all, when it gets to liquid they are free to move around because it's more space, when a gas they can move all around in the air.
(1 point) Which compound produces the greatest number of ions when one mole of it is dissolved in water
The question is incomplete, the complete question is;
Which produces the greatest number of ions when one mole dissolves in water? a. NaCl b. NH4Cl c. NH4NO3 d. Na2SO4
Answer:
Na2SO4
Explanation:
If we consider the compounds listed in the options one after the other;
NaCl produces two moles of ions in solution
NH4Cl produces two moles of ions in solution
NH4NO3 produces two moles of ions in solution
Na2SO4 produces three moles of ions in solution
We can see that Na2SO4 produces the greatest number of ions when one mole of the substance is dissolved in water, hence the answer above.
Given the reaction: N2 + O2 = 2NO for which the Keq at 2273 K is 1.2 x 10-4
a. Write the equilibrium constant expression for the reaction.
b. Write the equation that would allow you solve for the concentration of NO.
c. What is the concentration of NO if [NZ] = 0.166M and [02] = 0.145M?
Answer:
(a): The expression of equilibrium constant is [tex]K_{eq}=\frac{[NO]^2}{[N_2][O_2]}[/tex]
(b): The equation to solve the concentration of NO is [tex][NO]=\sqrt{K_{eq}\times [N_2]\times [O_2]}[/tex]
(c): The concentration of NO is 0.0017 M.
Explanation:
The equilibrium constant is defined as the ratio of the concentration of products to the concentration of reactants raised to the power of the stoichiometric coefficient of each. It is represented by the term [tex]K_{eq}[/tex]
(a):
The given chemical equation follows:
[tex]N_2+O_2\rightarrow 2NO[/tex]
The expression for equilbrium constant will be:
[tex]K_{eq}=\frac{[NO]^2}{[N_2][O_2]}[/tex]
(b):
The equation to solve the concentration of NO follows:
[tex][NO]=\sqrt{K_{eq}\times [N_2]\times [O_2]}[/tex] ......(1)
(c):
Given values:
[tex]K_{eq}=1.2\times 10^{-4}[/tex]
[tex][N_2]_{eq}=0.166M[/tex]
[tex][O_2]_{eq}=0.145M[/tex]
Plugging values in equation 1, we get:
[tex][NO]=\sqrt{(1.2\times 10^{-4})\times 0.166\times 0.145}[/tex]
[tex][NO]=\sqrt{2.88\times 10^{-6}}[/tex]
[tex][NO]=0.0017 M[/tex]
Hence, the concentration of NO is 0.0017 M.
If atoms are electrically neutral then how do they form bonds?
Answer:
The nucleus contains neutrons and protons; protons carry the positive charge. The shells contain electrons which carry the negative charge. So, how can the atom be changed. ... Covalent bonds are electrically neutral because they are not formed due to the transfer of electrons but sharing of electrons.Explanation:
Hope it helps ^-^
#CarryOnLearning
Answer:
When an atom has an equal number of electrons and protons, it has an equal number of negative electric charges (the electrons) and positive electric charges (the protons). The total electric charge of the atom is therefore zero and the atom is said to be neutral. ... Chemically, we say that the atoms have formed bonds
A 1.0 kg bottle of sodium carbonate (Na2CO3, 106.0 g/mol) is available to clean up 5.00 liters of spilled concentrated aqueous hydrochloric acid (9.75 M). Is this enough sodium carbonate to neutralize the acid according to the following reaction?
2 HCl (aq) + Na2CO3 (s) 2NaCl (aq) + CO2 (g) + H2O (l)
(1) No, there is approximately 40% too small amount of sodium carbonate needed.
(2) Yes, there is approximately 80% more than what is needed.
(3) No, there is approximately 60% too small amount of sodium carbonate needed.
(4) Yes, there is exactly enough sodium carbonate, but no excess.
(5) No, there is approximately 20% too small amount of sodium carbonate needed.
Answer:
The correct answer is option 4, that is, there is exactly enough sodium carbonate.
Explanation:
Based on the given question, the reaction will be,
2 HCl (aq) + Na2CO3 (s) ⇒ 2 NaCl (aq) + CO2 (g) + H2O (l)
Therefore, for neutralizing 2 moles of HCl, one mole of Na2CO3 is required.
No of moles present in 1 Kg or 1000 grams of Na2CO3 will be,
Moles = Weight/Molecular mass of Na2CO3
Moles = 1000 / 106 = 9.43
Thus, 9.43 moles of Na2CO3 is present.
No of moles present in 1 liter of 9.75 M HCl is 9.75.
No. of moles present in 5 Liters of HCl (9.75 M),
= 5 × 9.75 = 48.75
Thus, for 2 moles of HCl 1 mole of Na2CO3 is required. Now for 48.75 moles of HCl, the moles required of Na2CO3 is 9.75. Therefore, for complete neutralization, the moles of Na2CO3 required is 9.75, and the present moles is 9.43.
Hence, there is exactly enough sodium carbonate.
Find the mass of 0oC ice that 10 gof 100oC steam will completely melt. Latent heat of fusion of ice is 80cal/g oCand heat of vaporization of water 540 cal/g oC ?
Answer:
The right approach is "80 g".
Explanation:
Given:
[tex]L_f=80 \ Cal/g[/tex]
[tex]L_v=540 \ Cal/g[/tex]
[tex]S=1 \ Cal/g[/tex]
Now,
The amount of heat cooling will be:
= [tex]mL_v+mS \Delta T[/tex]
= [tex](10\times 540)+10\times 1\times (100-0)[/tex]
= [tex]5400+1000[/tex]
= [tex]6400 \ Cal[/tex]
then,
⇒ [tex]m_{ice} L_f=6400[/tex]
[tex]m_{ice}\times 80=6400[/tex]
[tex]m_{ice}=\frac{6400}{80}[/tex]
[tex]=80 \ g[/tex]
In the following reaction, C5H12(1) + 8 O2 (g) - 6 H2O (g) + 5 CO2 (g), how many
moles of water (H20) are produced by 14.2 moles of O2?
Answer:
10.65 moles
Explanation:
O2:H2O
8:6
14.2:x
x= 10.65 moles
How do isotopes of the same atom react chemically? How do isotopes of the same atom compare in size?
Atoms of the same elements differing in the number of neutrons in their nuclei are known as isotopes. Thus, isotopes of an element have the same atomic number but different atomic mass number. Isotopes of an element have similar chemical properties but different physical properties.
200 grams of iron (III) chloride reacts with ammonium carbonate [(NH4)2CO3] in the following equation.
FeCl3 + (NH4)2CO3 ---------> NH4Cl + Fe2(CO3)3
_ mole(s) of iron (III) carbonate [Fe2CO3)3] is/are produced in the balanced equation.
a
4
b
1
c
3
d
2
Answer:
0.616 moles of Fe₂(CO₃)₃ are produced when 200 g of FeCl₃ react
b. 1.
Explanation:
The balanced reaction is:
2FeCl₃ + 3(NH₄)₂CO₃ → 6NH₄Cl + Fe₂(CO₃)₃First we convert 200 grams of FeCl₃ into moles, using its molar mass:
200 g ÷ 162.2 g/mol = 1.23 mol FeCl₃Then we convert 1.23 moles of FeCl₃ into moles of Fe₂(CO₃)₃, using the stoichiometric coefficients of the balanced reaction:
1.23 mol FeCl₃ * [tex]\frac{1molFe_2(CO_3)_3}{2molFeCl_3}[/tex] = 0.616 mol Fe₂(CO₃)₃The closest answer would be option b. 1.
Explanation:
[tex]FeCl₃ + (NH₄)₂CO₃ → NH₄Cl + Fe₂(CO₃)₃[/tex]
first balance the chemical equation
[tex]2FeCl₃ + 3(NH₄)₂CO₃ → 6NH₄Cl + Fe₂(CO₃)₃[/tex]
2 mole. 3 mole. 6mole. 1mole
2*162g of FeCl₃ produce 236 g of Fe₂(CO₃)₃
200g of of FeCl₃
produce 236/(2*162)*20=145.68 g of Fe₂(CO₃)₃
1 mole of Fe₂(CO₃)₃=236g
145.68g of Fe₂(CO₃)=1/236*145.68=}0.61mole
closest answer is b 1
b.1mole(s) of iron (III) carbonate [Fe2CO3)3] is/are produced in the balanced equation
Which of the following describes a spectrum?
A. A measurement of the energy associated with an electron
transition
B. A piece of glass that causes light to be divided into different
colors
C. A range of wavelengths or frequencies of electromagnetic
radiation
D. A list of the quantum numbers assigned to a particular electron
Answer: The Answer would be C
Explanation: A spectrum is a Range of Wavelengths and Frequencies of Electromagnetic Radition.
The statement that describe spectrum is a range of wavelengths or frequencies of electromagnetic radiation.
What is Spectrum?Spectrum arrangement or electromagnetic radiations base on their wavelength and frequency which can be visible light, ultraviolet, and infrared light. An instrument that is use for visual observation of spectra is called a spectroscope.
Therefore, The statement that describe spectrum is a range of wavelengths or frequencies of electromagnetic
radiation.
Learn more about spectrum from the link below.
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If the molecule has n-C2 axes perpendicular to its Cn axis, choose True. Otherwise, choose False. Be sure to build a model or draw the structure before selecting your answer. If needed, search for the molecular structure online or in a textbook.XeF4[PdCl4]2−naphthalenefuran, C4H4O
Answer:
XeF4 True
[PdCl4]2− True
naphthalene True
Furan False
C4H4O False
Explanation:
From the given information:
Only XeF4; [PdCl4]2−; naphthalene are true. This is because their molecules contain -nC₂ axis which is perpendicular to the Cn axis. The image attached below shows the structural formula of each compound, there below, we can see that Furan only possesses one C₂ axis but not -nC₂ ⊥ C₂.
Explain why the coefficients on the left side of the equation don’t necessarily equal the coefficients on the right side of the equation. Is this possible if mass is being conserved?
Answer:
Explanation:
Short answer: Yes.
The coefficients may not be conserved, but mass always has to be. Take this equation as an example
2 Mg3P2 ===> 6Mg + P4
There is a 2 on the left side and 6 and 1 on the right. I hope you mean that the coefficient 2 is not equal to 7.
But let's look a little closer. You have to look at the molecular structure of the left and right side.
2Mg3P2 has 6 Mgs and 4 Ps on the left side.
6Mg is on the right. They are free standing.
P4 has 1 molecule consisting of 4 Ps.
Everything balances.
This is a terrific question to be asking. You need to understand the internal balance numbers vs the molecular ones on the out side.
That sounds like a bit of gobbledygook and it takes a bit of study.
2 Mg3P2 means that Mg3P2 is written twice.
Mg3P2 ==> "3 Mg2+ + 2P3+ and there is another one written the same way.
Mg3P2 ==> "3 Mg2+ + 2P3+
PLEASE HELP ME!!!!!!!
Answer:
The heat capacity of the metal underneath the gold is 0.431 J/g°C
Explanation:
Using the formula as outlined in the image:
Q = m × c × ∆T
Where;
Q = amount of heat energy (J)
m = mass of substance (g)
c = specific heat capacity (J/g°C)
∆T = change in temperature (°C)
According to the information in this question;
Q = 503.9J
m = 23.02g
c = ?
∆T = 74°C - 23.2°C = 50.8°C
Using Q = m × c × ∆T
c = Q ÷ m∆T
c = 503.9 ÷ (23.02 × 50.8)
c = 503.9 ÷ 1169.42
c = 0.431 J/g°C
From the above heat capacity of the metal underneath the gold, it is obvious that the metal is not pure gold (c = 0.129J/g°C)
Congratulations you have worked hard and now you are done with the year! I am so proud of you!
Answer:
lololol
Explanation:
Pick the correct statement about the pure water. Group of answer choices Pure water contains no ions. Pure water contains equal amounts of hydroxide [OH-] and hydronium [H3O ] ions. Pure water contains larger amounts of hydroxide [OH-] than hydronium [H3O ] ions. Pure water is an electrolyte. Pure water contains smaller amounts of hydroxide [OH-] than hydronium [H3O ] ions.
Answer:
Pure water contains no ions. TRUE
Pure water contains equal amounts of hydroxide [OH-] and hydronium [H3O+ ] ions. TRUE
Explanation:
This is the equilibrium for pure water:
2H₂O ⇄ H₃O⁺ + OH⁻ Kw
We see that pure water has no Ions. Pure water can not conduct electricity.
Generally ionized water comes from the water tap.
Another feature of pure water is pH.
Definetely pH of pure water is : 7
As pH = 7, [H₃O⁺] = 1×10⁻⁷
Then, [OH⁻] = 1×10⁻⁷
This is reazonable because Kw is 1×10⁻¹⁴ and Kw = [H₃O⁺] . [OH⁻]
In conclussion:
Pure water contains no ions. TRUE
Pure water contains equal amounts of hydroxide [OH-] and hydronium [H3O+ ] ions. TRUE
Pure water contains larger amounts of hydroxide [OH-] than hydronium [H3O+] ions. FALSE
Pure water is an electrolyte. FALSE
Pure water contains smaller amounts of hydroxide [OH-] than hydronium [H3O ] ions. FALSE
Choose the group that corresponds to each element.
Alkali Metal
Alkali earth metal
Halogen
Noble gas
The group corresponding to alkali metal, alkali earth metal, halogen, and noble gas is IA,IIA, 17, 18 group respectively.
Alkali metals have one outermost electron in their valence shell. They are kept under oil and are in the group IA of the periodic table.Alkaline earth metals have two outermost electrons in their valence shell. Examples are beryllium, magnesium, etc.Halogens have seven electrons in their outermost shells. They are in the periodic table in group 17 naming fluorine to iodine.Noble gas is the one that has fulfilled electronic configuration and doesn't react with any other compound.This is present in group 18 of periodic table.Learn more about alkali metals at:
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WILL GIVE BRAINLIEST TO FIRST ANSWER
picture ⬆️
Answer: A Molecular Approach, 2/e. Mole ratio. 2 mol C4H10 : 13 mol O2 : 8 mol CO2 : 10 mol H2O. ❖ 2 molecules of C4H10 react ... of aluminum and 73.15 g of sulfur are combined to form aluminum sulfide according to the equation:.
Explanation:
In a different titration, a 0.7529 g sample of a mixture of solid C6H5COOH and solid NaCl is dissolved in water and titrated with 0.150 M NaOH. The equivalence point is reached when 24.78 mL of the base solution is added. Calculate each of the following.
a. The mass, in grams, of benzoic acid in the solid sample
b. The mass percentage of benzoic acid in the solid sample
Answer:
a. 0.4539g benozic acid
b. 60.29% of benzoic acid in the solid sample
Explanation:
The benzoic acid reacts with NaOH as follows:
C6H5COOH + NaOH → C6H5COONa + H2O
Where 1 mole of the acid reacts per mole of NaOH
The NaCl doesn't react with NaOH
To solve this question we must find the moles of NaOH added = Moles of benzoic acid. With the moles of the acid and its molar mass (C6H5COOH = 122.12g/mol) we can find the mass of the acid and its mass percentage:
a. Moles NaOH = Moles Benzoic acid:
24.78mL = 0.02478L * (0.150mol / L) = 0.003717 moles Benozic acid
Mass benzoic acid:
0.003717 moles Benozic acid * (122.12g / mol) = 0.4539g benozic acid
b. Mass percentage is:
0.4539g / 0.7529g * 100 = 60.29% of benzoic acid in the solid sample
What is the [OH-] in a solution if the [H*] = 1.2 x 10-3 M?
We know that [OH⁻] * [H⁺] = 10⁻¹⁴
plugging the value of [H⁺]
[OH⁻] * 1.2 * 10⁻³ = 10⁻¹⁴
[OH⁻] = 10⁻¹⁴ * (10³/1.2)
[OH⁻] = 833.3 * 10⁻¹⁴
[OH⁻] = 8.33 * 10⁻¹²
Write a conclusion statement that addresses the following questions: • Explain what the color change indicated about the changes in the concentrations of Co(H2O)62+ and CoCl42– in each trial. • Do your data support or fail to support your hypothesis (include examples)? • How do you think the investigation can be explored further?
When the concentration of the HCl is varied, the color of the solution is changed as the equilibrium position moves to the left or right.
What is equilibrium?The term equilibrium in a chemical reaction connotes that the forward and the revers reactions proceed at the same rate. Let us note that Co(H2O)6^2+ is pink in color while CoCl4^2– is blue in color.
As such, when the concentration of the HCl is varied, the color of the solution is changed as the equilibrium position moves to the left or right.
Learn more anout equilibrium: https://brainly.com/question/365923
PLEASE HELP ME!!!!
TRUE or FALSE: When sperm and egg cells combine in fertilization, the
offspring ends up with the same number of chromosomes as their
parents.
Answer: False
Explanation:
Hope this help
Answer:
True.
Explanation:
Every child will contain the same number of chromosomes as the parents (otherwise they wouldn't be considered the same species). Additionally, animals can only mate with a species containing the same number of chromosomes as themselves. This means if the offspring of the parents had a different number fo chromosomes the offspring would be unable to mate with animals of it's own species.
Map
Formulate your hypothesis.
List down the materials.
• Write the methods.
Answer:
How to Formulate an Effective Research Hypothesis
State the problem that you are trying to solve. Make sure that the hypothesis clearly defines the topic and the focus of the experiment.
Try to write the hypothesis as an if-then statement. ...
Define the variables.
Explanation:
Given 32.0 g of water, if we see a temperature change from 25.0°C to 20.0°C, then how much heat energy (q) is transferred from the water?
(The specific heat of water is 4.184 J/g°C )
Answer:
Q = 669.44 J
Explanation:
Given that,
Mass of water, m = 32 g
The temperature change from 25.0°C to 20.0°C.
We need to find the amount of heat energy transferred. Let it is Q. We know that,
[tex]Q=mc\Delta T[/tex]
Where
c is the specific heat of water
Put all the values,
[tex]Q=32\times 4.184 \times (20-25)\\Q=669.44\ J[/tex]
So, 669.44 J of heat energy is transferred from the water.
A chemist must dilute of aqueous silver perchlorate solution until the concentration falls to . He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Round your answer to significant digits
The given question is incomplete, the complete question is:
A chemist must dilute 54.1 mL of 20.2 M aqueous silver perchlorate (AgC102) solution until the concentration falls to 3.00 M. He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in liters. Round your answer to 3 significant digits.
Answer:
The correct answer is 0.364 L.
Explanation:
A solution is made less concentrated by diluting it with a solvent. There is no change in the number of moles when more solvent is added to the solution. In case, if the solution is diluted from V1 to V2, a change is noticed in the molarity of the solution based on the given equation,
M1V1 = M2V2
In the given case, the V1 or the volume of the original solution is 54.1 ml, M1 or the molarity of the original solution is 20.2 M.
The M2 or the molarity of the diluted solution is 3.00 M, there is a need to find the V2 or the volume of the diluted solution.
Now by putting the values in the equation we get,
= 20.2M * 54.1 ml = 3.0 M * V2
V2 = 364.27 ml
It is known that 1000 ml is equivalent to 1L, therefore, 1 ml = 0.001 L
Now, the value of V2 will be,
= 364.27 * 0.001 L = 0.36427 L or 0.364 L
Now we need to find the amount of NF3 that can be formed by the complete reactions of each of the reactants. If all of the N2 was used up in the reaction, how many moles of NF3 would be produced
The question is incomplete, the complete question is:
Nitrogen and fluorine react to form nitrogen fluoride according to the chemical equation:
[tex]N_2(g)+3F_2(g)\rightarrow 2NF_3(g)[/tex]
A sample contains 19.3 g of [tex]N_2[/tex] is reacted with 19.3 g of [tex]F_2[/tex]. Now we need to find the amount of [tex]NF_3[/tex] that can be formed by the complete reactions of each of the reactants.
If all of the [tex]N_2[/tex] was used up in the reaction, how many moles of [tex]NF_3[/tex] would be produced?
Answer: 1.378 moles of [tex]NF_3[/tex] are produced in the reaction.
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.
Excess reagent is defined as the reagent which is left behind after the completion of the reaction.
In the given chemical reaction, [tex]N_2[/tex] is considered as a limiting reagent because it limits the formation of the product and it was completely consumed in the reaction.
We are given:
Mass of [tex]N_2[/tex] = 19.3 g
Molar mass of [tex]N_2[/tex] = 28.02 g/mol
Putting values in equation 1:
[tex]\text{Moles of }N_2=\frac{19.3g}{28.02g/mol}=0.689mol[/tex]
For the given chemical reaction:
[tex]N_2(g)+3F_2(g)\rightarrow 2NF_3(g)[/tex]
By the stoichiometry of the reaction:
1 mole of [tex]N_2[/tex] produces 2 moles of [tex]NF_3[/tex]
So, 0.689 moles of [tex]N_2[/tex] will produce = [tex]\frac{2}{1}\times 0.689=1.378mol[/tex] of [tex]NF_3[/tex]
Hence, 1.378 moles of [tex]NF_3[/tex] are produced in the reaction.
what is a compound ? Give five examples ?
[tex]\huge\mathsf{\red{\underline{\underline{Compound}}}}[/tex]
[tex]{\green{\dashrightarrow}}[/tex]A chemical compound is a chemical substance that is made of two or more atoms of different elements that share a chemical bond.
[tex]{\green{\dashrightarrow}}[/tex]A chemical formula represents the ratio of atoms per element that make up the chemical compound.
[tex]\large{\pink{\sf{5~ Examples~ of~ Compound~ are:-}}}[/tex]
Example 1 :-Water (H2O, consisting of 2 hydrogen atoms and one oxygen atom)Example 2 :- Carbon dioxide (CO2, consisting of one carbon atom and two oxygen atoms)Example 3 :- Sodium Chloride (NaCl, consisting of one sodium atom and one chloride atom)Example 4:-Methane (CH4, consisting of one carbon atom and four hydrogen atoms)Example 5 :- Pure glucose is a compound made from three elements - carbon, hydrogen, and oxygen. The ratio of hydrogen to carbon and oxygen in glucose is always 2:1:1.