4 Questions:

How many moles of chlorine are present in 3 moles of MgCI2?

6, 3, 5, or 4?

How many moles of H20 are needed to produce 1 mole of 02 in the following equation? 2H20->2H2+102 (not 102 it's 1 singlet oxygen)

1, 2, 3, or 4?

How many moles of hydrogen atoms are present in 1 mole of H2 gas?

3, 2, 1, or 4?

How many atoms or molecules are in a mole?

1. 1

2. An 6.02 x 10

3. 2

4. 6.02 x 10^23

1) 3.0 moles.

2) 2.0 moles.

3) 2.0 moles of H atoms.

4) 4. 6.02 x 10²³.

Explanation:

Q1: How many moles of chlorine are present in 3 moles of MgCI₂?

MgCl₂ is dissociated according to the equation:

MgCl₂ → Mg + Cl₂.

Every 1.0 mole of Mg is dissociated to 1.0 mol of Mg and 1.0 mol of Cl₂.

∵ 1.0 mol of MgCl₂ gives 1.0 mol of Cl₂.

∴ 3.0 mol of MgCl₂ gives 3.0 mol of Cl₂.

Q2: How many moles of H₂0 are needed to produce 1 mole of O₂ in the following equation? 2H₂O → 2H₂ + O₂.

From the balnced equation:

2H₂O → 2H₂ + O₂.

2.0 moles of H₂O produce 2.0 moles of H₂ and 1.0 mole of O₂.

∴ We need 2.0 moles of H₂O to produce 1.0 mole of O₂.

Q3: How many moles of hydrogen atoms are present in 1 mole of H2 gas?

H₂ is dissociated according to:

H₂ → 2H.

1.0 mol of H₂ is dissociated to produce 2 atoms of H.

∴ 1.0 mol of H₂ contains 2.0 moles of H atoms.

Q4: How many atoms or molecules are in a mole?

It is known that every mole of any compound contains Avogadro's number of atoms or molecules (6.022 x 10²³).

So, the answer is: 4. 6.02 x 10²³.