Zn+2HCl=ZnCl2+H2 How many grams of the reactant remains unreacted?
IDK. How many grams did you have at the beginning. What was the concentration of the HCl?
To determine how many grams of the reactant remains unreacted, we need more information such as the initial masses or quantities of the reactants. The given chemical equation only tells us the stoichiometry of the reaction, but it does not give us the starting quantities.
To calculate how many grams of the reactant remains unreacted in the given chemical reaction, you need to know the quantities of the reactants involved and their stoichiometric ratios.
Let's assume you know the mass of zinc (Zn) and hydrochloric acid (HCl) used in the reaction. For this example, let's say you have 10 grams of zinc and 20 grams of hydrochloric acid.
1. Determine the molar masses: The molar mass of zinc (Zn) is approximately 65.38 g/mol, and the molar mass of hydrochloric acid (HCl) is approximately 36.46 g/mol.
2. Convert masses to moles: Divide the mass of each substance by its molar mass to obtain the number of moles. In this example, you have 10 g Zn / 65.38 g/mol = 0.153 moles of Zn and 20 g HCl / 36.46 g/mol = 0.548 moles of HCl.
3. Use the stoichiometric ratio: Examine the balanced equation to determine the stoichiometric ratio between the reactants. From the equation, you can see that one mole of Zn reacts with two moles of HCl to produce one mole of ZnCl2 and one mole of H2.
Since the stoichiometric ratio is 1:2 for Zn to HCl, you need to have twice as many moles of HCl as moles of Zn to react completely.
4. Calculate the moles required for complete reaction: Multiply the moles of Zn by the stoichiometric ratio. In this case, 0.153 moles of Zn * 2 = 0.306 moles of HCl are required for complete reaction.
5. Determine the excess reactant: Subtract the actual moles of the excess reactant from the stoichiometric moles. In this example, 0.548 moles of HCl - 0.306 moles of HCl = 0.242 moles of excess HCl.
6. Convert moles to grams: Multiply the moles of excess reactant by the molar mass of HCl. In this case, 0.242 moles of HCl * 36.46 g/mol = 8.83 grams of excess HCl.
Therefore, in this example, 8.83 grams of hydrochloric acid remain unreacted.