Answer to Question #106495 in General Chemistry for Brendy Fanfan

Question

Due to the Corona virus Im really struggling in my chemistry class, without a professor to help me. Can someone help me find the answer for this question? I've been stuck on it for an hour now...

zinc + hydrochloric acid ----- > zinc(II) chloride + hydrogen

How many moles of hydrochloric acid need to react with 4.524 grams of zinc?

Answer 1

In order to answer the question and find the number of the moles of hydrochloric acid (HCl) needed to react with 4.524 grams of zinc (Zn), one should first correctly write the reaction equation and equilibrate it. Here is the correct equation:

Zn + 2HCl -> ZnCl₂ + H₂

As you can see from the equation, 1 mole of zinc reacts with 2 moles of hydrochloric acid. Therefore, the number of the moles of hydrochloric acid needed is twice the number of the moles of zinc.

Let's calculate the number of the moles of zinc. We know its molar mass, we can find it in the Periodic Table: 65.38 g/mol. The number of the moles of zinc is its mass divided by its molar mass:

$n = \frac{m}{M} = \frac{4.524}{65.38} = 0.06920 \text{ mol}$

Now, we can calculate the number of the moles of hydrochloric acid, needed to react with 4.524 grams of zinc: 2x0.06920, or 0.1384 mol.

Answer: The number of the moles of hydrochloric acid, needed to react with 4.524 grams of zinc is 0.1384 mol.