Question

Lab: Limiting Reactant and Percent Yield

Answer 1

Answer : If a substance is the limiting reactant, then it limits the formation of products because in the reaction it is present in limited amount.

Explanation :

While observing a chemical reaction, we can tell about whether a reactant is limiting or excess.

Step 1 : first write the chemical reaction and then balanced the chemical equation.

$C_2H_4+H_2\rightarrow C_2H_6$

Step 2 : convert the given masses into the moles if mass of $C_2H_4$ is 10.5 g and molar mass of $C_2H_4$ is 28 g/mole and the mass of hydrogen is 0.40 g and molar mass of hydrogen is 2 g/mole.

$\text{moles of }C_{2}H_{4}=\frac{10.5g}{28g/mole}=0.375moles$

$\text{moles of }H_{2}=\frac{0.40g}{2g/mole}=0.20moles$

Step 3 : Now we have to determine the limiting reagent and excess reagent.

$\text{ moles of }C_{2}H_{4}\text{ in excess}=0.375-0.20=0.175\text{moles}$

Now we conclude that $C_{2}H_{4}$ is the limiting reagent and hydrogen is an excess reagent.

Hypothesis :

Limiting reagent : It is the reagent in the chemical reaction that is totally consumed when the chemical reaction is complete.  Limiting reagent limits the formation of products.

Answer 2

Answer:

If a substance is the limiting reactant, then . . .

it will limit the formation of products

because . . .

the reaction is presented at limited

Explanation:

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