Which of the following chemical equations is correctly balanced?
A.) H2 + O2 → H2O
B.) 2 C2H4O + 5 O2 → 4 CO2 + 4 H2O
C.) K2S + I2 → 2 KI + S
D.) CaCO3 + 2 HCl → CaCl2 + 2 CO2 + H2O

Respuesta :

Option B and C both are balanced.

A chemical reaction is said to be balanced if all the constituent on the left side of the reaction arrow are equal to right side.

(A) The chemical reaction is as follows:

[tex]H_{2}+O_{2}\rightarrow H_{2}O[/tex]

There are 2 hydrogen atoms and 2 oxygen atoms on left side of the reaction arrow and 2 hydrogen and 1 oxygen on right hand side thus, number of oxygen atoms are not balanced.

Therefore, the above chemical reaction is not balanced.

(B) The chemical reaction is as follows:

[tex]2C_{2}H_{4}O+5O_{2}\rightarrow 4CO_{2}+4H_{2}O[/tex]

There are 4 carbon atoms, 8 hydrogen atoms and 12 oxygen atoms on both side of the reaction arrow thus, the chemical reaction is balanced.

(C) The chemical reaction is as follows:

[tex]K_{2}S+I_{2}\rightarrow 2KI+S[/tex]

There are 2 potassium atoms, 1 sulfur atom and 2 iodine atoms on both side of the reaction arrow thus, it is a balanced chemical reaction.

(D) The  chemical reaction is as follows:

[tex]CaCO_{3}+2HCl\rightarrow CaCl_{2}+2CO_{2}+H_{2}O[/tex]

There is 1 calcium atom, 1 carbon atom, 3 oxygen atoms, 2 hydrogen atoms and 2 chlorine atoms on left side of the reaction arrow and 1 calcium atom, 2 chlorine atoms, 2 carbon atoms, 5 oxygen atoms and 2 hydrogen atoms on right hand side of the reaction arrow. Thus, number of carbon and oxygen atoms are not balanced in the chemical reaction.

A balanced chemical reaction has the same and a balanced number of stoichiometry coefficients. Option B. [tex]\rm 2 C_{2}H_{4}O + 5 O_{2} \rightarrow 4 CO_{2} + 4 H_{2}O[/tex] and option D. [tex]\rm K_{2}S + I_{2} \rightarrow 2 KI + S[/tex] are balanced equations.

What is a balanced chemical reaction?

A balanced chemical reaction is the equated reaction and depiction of the chemical reactants and the products of the reaction. They have balanced stoichiometry coefficients on the left and the right side of the reaction.

In the second reaction,  [tex]\rm 2 C_{2}H_{4}O + 5 O_{2} \rightarrow 4 CO_{2} + 4 H_{2}O[/tex], the number of carbon atoms are four on both sides, 8 atoms of hydrogen on both sides and 12 atoms of oxygen balanced on both sides of the chemical reaction.

In the third reaction, [tex]\rm K_{2}S + I_{2} \rightarrow 2 KI + S[/tex], 2 atoms of potassium, 2 atoms of iodine and 1 atom of sulphur is balanced.

Therefore, reactions B and D are balanced reactions.

Learn more about the balanced equations here:

https://brainly.com/question/8033286