Why did the acid go to the gym? To get better at balancing equations!
Alright, let's get down to business. The unbalanced chemical equation for the reaction between sulfuric acid (H2SO4) and potassium hydroxide (KOH) is:
H2SO4 + KOH → K2SO4 + H2O
To find the molar mass of a compound, you need to add up the atomic masses of all the atoms in that compound. For example, for sulfuric acid (H2SO4), the molar mass would be:
(2 x atomic mass of hydrogen) + atomic mass of sulfur + (4 x atomic mass of oxygen)
Now, to balance the chemical equation, we want the same number of atoms on both sides. We start by balancing the atoms that appear in only one compound. In this case, we have potassium (K), sulfur (S), and hydrogen (H).
In the unbalanced equation, we have 1 potassium atom on the left (from KOH) but 2 potassium atoms on the right (from K2SO4). To balance them out, we put a 2 in front of KOH:
H2SO4 + 2KOH → K2SO4 + H2O
Next, we have 1 sulfur atom on the left but 1 sulfur atom on the right, so sulfur is already balanced.
Lastly, we have 2 hydrogen atoms on the left (from H2SO4) and 2 hydrogen atoms on the right (from H2O). Hydrogen is balanced as well.
Now we have a balanced chemical equation:
H2SO4 + 2KOH → K2SO4 + H2O
This balanced equation allows us to determine the mole ratio between the reactants and products. In this case, the mole ratio tells us that for every 1 mole of sulfuric acid, we need 2 moles of potassium hydroxide to produce 1 mole of potassium sulfate and 1 mole of water.
To find the mass of sulfuric acid required to react with 1.27 g of potassium hydroxide, we need to convert grams of potassium hydroxide to moles, using its molar mass. Then, we use the mole ratio from the balanced equation to determine the moles of sulfuric acid needed. Finally, we convert moles of sulfuric acid to grams, using its molar mass.
For the number of significant figures, you should use the same number of significant figures as the given mass of potassium hydroxide. In this case, it's 1.27 g, so your final answer should also have 3 significant figures.
Hope this chemistry clown act didn't leave you in acid reflux!