4questions:

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 → 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.

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 → 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?

So, the answer is: 4. 6.02 x 10²³.

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

10 years is the answer