Answer
Verified
396.9k+ views
Hint: The reactant that fully reacts in the reaction is called reactant limiting or reagent limiting. The reactant that is not fully consumed in the reaction is called excess reactant. You should write the balanced reaction equation before solving the question. A balanced equation is an equation for a chemical reaction in which the number of atoms in the reaction for each element and the total charge for both the reactants and the products is equal.
Complete answer:
The Law of Definite Proportions, states that any chemical compound will always contain a fixed ratio of elements by mass. The Law of Definite Proportions is also sometimes called Proust's Law.
Mg is burnt with ${{O}_{2}}$ in a closed vessel to produce MgO.
The reaction used in question is: $2Mg+{{O}_{2}}\to 2MgO$
1 mole of ${{O}_{2}}$ reacts with 2 moles of Mg to produce 2 moles of MgO.
Moles (n) = $\dfrac{given weight(w)}{molar mass(m)}$
As given in question, the weight of ${{O}_{2}}$ is 0.28g.
Molar mass of ${{O}_{2}}$ is 32.
Therefore, numbers of moles of ${{O}_{2}}$ $\dfrac{0.28}{32}=0.00875$
0.00875 moles of ${{O}_{2}}$ reacts with $2\times 0.00875$ moles of Mg $=0.0175$ moles of Mg to produce $=0.0175$ moles of MgO.
Mass of magnesium that reacts = $moles\times molar mass$
Molar mass of Mg is 24.
Hence, mass of magnesium that reacts $0.0175\times 24=0.42$
That means, out of the 1g of Mg, only 0.42g is used.
Therefore, Mg is in excess by (1 - 0.42) = 0.58 g.
Therefore, limiting reagent is ${{O}_{2}}$.
So, the correct answer is “Option B”.
Note: The limiting reagent (also known as limiting reactant) in a chemical reaction is a reactant that is totally consumed when the chemical reaction is completed. The amount of product formed is limited by this reagent, since the reaction cannot continue without it.
Remember this reaction equation,
$2Mg+{{O}_{2}}\to 2MgO$
When 2 moles of Mg combine with 1 mole of ${{O}_{2}}$ to produce 2 moles of MgO.
Complete answer:
The Law of Definite Proportions, states that any chemical compound will always contain a fixed ratio of elements by mass. The Law of Definite Proportions is also sometimes called Proust's Law.
Mg is burnt with ${{O}_{2}}$ in a closed vessel to produce MgO.
The reaction used in question is: $2Mg+{{O}_{2}}\to 2MgO$
1 mole of ${{O}_{2}}$ reacts with 2 moles of Mg to produce 2 moles of MgO.
Moles (n) = $\dfrac{given weight(w)}{molar mass(m)}$
As given in question, the weight of ${{O}_{2}}$ is 0.28g.
Molar mass of ${{O}_{2}}$ is 32.
Therefore, numbers of moles of ${{O}_{2}}$ $\dfrac{0.28}{32}=0.00875$
0.00875 moles of ${{O}_{2}}$ reacts with $2\times 0.00875$ moles of Mg $=0.0175$ moles of Mg to produce $=0.0175$ moles of MgO.
Mass of magnesium that reacts = $moles\times molar mass$
Molar mass of Mg is 24.
Hence, mass of magnesium that reacts $0.0175\times 24=0.42$
That means, out of the 1g of Mg, only 0.42g is used.
Therefore, Mg is in excess by (1 - 0.42) = 0.58 g.
Therefore, limiting reagent is ${{O}_{2}}$.
So, the correct answer is “Option B”.
Note: The limiting reagent (also known as limiting reactant) in a chemical reaction is a reactant that is totally consumed when the chemical reaction is completed. The amount of product formed is limited by this reagent, since the reaction cannot continue without it.
Remember this reaction equation,
$2Mg+{{O}_{2}}\to 2MgO$
When 2 moles of Mg combine with 1 mole of ${{O}_{2}}$ to produce 2 moles of MgO.
Recently Updated Pages
Basicity of sulphurous acid and sulphuric acid are
Three beakers labelled as A B and C each containing 25 mL of water were taken A small amount of NaOH anhydrous CuSO4 and NaCl were added to the beakers A B and C respectively It was observed that there was an increase in the temperature of the solutions contained in beakers A and B whereas in case of beaker C the temperature of the solution falls Which one of the following statements isarecorrect i In beakers A and B exothermic process has occurred ii In beakers A and B endothermic process has occurred iii In beaker C exothermic process has occurred iv In beaker C endothermic process has occurred
What is the stopping potential when the metal with class 12 physics JEE_Main
The momentum of a photon is 2 times 10 16gm cmsec Its class 12 physics JEE_Main
How do you arrange NH4 + BF3 H2O C2H2 in increasing class 11 chemistry CBSE
Is H mCT and q mCT the same thing If so which is more class 11 chemistry CBSE
Trending doubts
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
Write an application to the principal requesting five class 10 english CBSE
Difference Between Plant Cell and Animal Cell
a Tabulate the differences in the characteristics of class 12 chemistry CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
What organs are located on the left side of your body class 11 biology CBSE
Discuss what these phrases mean to you A a yellow wood class 9 english CBSE
List some examples of Rabi and Kharif crops class 8 biology CBSE