Answer:- 448 mL of hydrogen gas are formed.
Solution:- It asks to calculate the volume of hydrogen gas formed in milliliters at STP when 0.020 moles of magnesium reacts with excess HCl acid. The balanced equation is:
There is 1:1 mol ratio between Mg and hydrogen gas. So, the moles of hydrogen gas is also equals to the moles of Mg reacted.
moles of Hydrogen gas formed = 0.020 mol
At STP, volume of 1 mol of the gas is 22.4 L. We need to calculate the volume of 0.02 moles of hydrogen gas.
= 0.448 L
They want answer in mL. So, let's convert L to mL using the conversion formula, 1L = 1000mL
= 448 mL
So, 0.020 moles of magnesium would produce 448 mL of hydrogen gas at STP on reacting with excess of HCl acid.
If the bonds of the product store 27 KJ more energy than the bonds of the reactants, It means the surroundings absorb 27 kj of energy from the reaction system Hence, Option (D) is the correct answer
<h3>What is the Exothermic reaction ?</h3>
An exothermic process releases heat, causing the temperature of the immediate surroundings to rise.
The bonds of the product store 27 KJ more energy than the bonds of the reactants, It means that energy has been absorbed by the surrounding as the product formed is more stable due to more stronger bond
This can be inferred from more stored energy with in the bonds and Thus, It is a exothermic reaction.Hence, Option (D) is the correct answer
Learn more about exothermic reaction here ;
brainly.com/question/9799465
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