Answer:
8.96×10²³ molecules of HCl are needed
Explanation:
We analyse the reaction:
Mg(OH)₂(s) + 2 HCl(aq) → 2 H₂O(l) + MgCl₂(aq)
1 mol of magnessium hydroxide reacts with 2 moles of hydrochloric acid to produce 2 moles of water and 1 mol of magnessium chloride.
We determine the moles of salt, to know how many moles of it we have formed. → 70.84 g . 1 mol / 95.2g = 0.744 moles
Ratio is 2:1, so let's make a rule of three:
1 mol of chloride can be produced by 2 moles of HCl
Then, 0.744 of chloride were produced by (0.744 m . 2 m) / 1 m = 1.48 moles of HCl
Let's find out the number of molecules.
1.48 moles . 6.02×10²³ molecules / 1 mol = 8.96×10²³ molecules of HCl are needed
Answer:
We need 8.96*10^23 molecules HCl
Explanation:
Step 1: Data given
Mass of MgCl2 = 70.84 grams
Molar mass of MgCl2 = 95.211 g/mol
Number of Avogadro = 6.022 * 10^23 / mol
Step 2: The balanced equation
Mg(OH)₂(s) + 2 HCl(aq) → 2 H₂O(l) + MgCl₂(aq)
Step 3: Calculate moles MgCl2
Moles MgCl2 = mass MgCl2 / molar mass MgCl2
Moles MgCl2 = 70.84 grams / 95.211 g/mol
Moles MgCl2 = 0.744 moles
Step 4: Calculate moles HCl
For 2 moles H2O and 1 mol MgCl2 produced , we need 1 mol Mg(OH)2 and 2 moles HCl
For 0.744 moles MgCl2 we need 2*0.744 = 1.488 moles HCl
Step 5: Calculate molecules
Molecules = 1.488 moles * 6.022 * 10^23 / mol
Molecules = 8.96*10^23 molecules
We need 8.96*10^23 molecules HCl
