Answer:
1.645 moles of excess reactant that is of magnesium metal are left over.
Explanation:
Moles of magnesium metal = 3.29 mol
Moles of HCl = 3.29 mol

According to recation, 2 moles of HCl reacts with 1 mol of magnesium metal, then 3.29 moles of HCl will react with :
of magnesium metal
Moles of HCl left = 3.29mol - 3.29 mol = 0
Moles of magnesium metal left = 3.29 mol - 1.645 mol = 1.645 mol
1.645 moles of excess reactant that is of magnesium metal are left over.
Answer:
The number before any molecular formula applies to the entire formula. So here you have five molecules of water with two hydrogen atoms and one oxygen atom per molecule. Thus you have ten hydrogen atoms and five oxygen atoms in total.
Answer:
Explanation:
Carbon Dioxide-CO2
To get molecules, we must convert grams to moles and moles to atoms using Avogadro's number.
Molar mass of CO2=
C:12.0g+O:16.0gx2=44.0g CO2
25.0g CO2 | 1 mol CO2 | 6.02x10 23 molecules CO2
= 3.42x10 23 molecules CO2
1 | 44.0g CO2 | 1 mol CO2
Now to get the number of oxygen atoms.
Since there are 3 atoms in CO2 and 2 of them are oxygen, we will divide by 3 (1.14x10 23) and multiply by 2 (2.28 x10 23)
So the number of oxygen atoms in 25.0 grams of CO2 is 2.28x10 23 or 228 000 000 000 000 000 000 000