Question

Chlorine gas will react with iron metal.

Exactly 21.3 g of chlorine reacts with 11.2 g of iron.
How many iron atoms react with 30 molecules of chlorine?
A 10
B 15
C 20
D 30

Answer 1

Approximately 9.96 x 10⁻²⁵ iron atoms react with 30 molecules of chlorine.

Step-by-step explanation:

Let's start by finding the number of iron atoms that react with 30 molecules of chlorine.

From the given information, 21.3 g of chlorine reacts with 11.2 g of iron.

Since the molar mass of chlorine gas (Cl₂) is approximately 70.90 g/mol, we can calculate the number of moles of chlorine gas in 30 molecules:

(30 molecules) / (6.022 x 10²³ molecules/mol) = 4.98 x 10⁻²⁵ mol

According to the balanced equation, 1 mole of chlorine gas reacts with 2 moles of iron. Therefore, the number of moles of iron required to react with the given amount of chlorine gas is:

(4.98 x 10⁻²⁵ mol Cl₂) x (2 mol Fe / 1 mol Cl₂) = 9.96 x 10⁻²⁵ mol Fe

Finally, we can use the molar mass of iron (Fe), which is approximately 55.85 g/mol, to calculate the mass of iron:

(9.96 x 10⁻²⁵ mol Fe) x (55.85 g / mol Fe) = 5.56 x 10⁻²³ g Fe

Therefore, the mass of iron that reacts with 30 molecules of chlorine is approximately 5.56 x 10⁻²³ grams. Since iron has one atom per mole, the number of iron atoms will be the same as the number of moles, which is approximately 9.96 x 10⁻²⁵ atoms.

Answer 2

If 0.3 mol of chlorine reacts with 0.2 mol of iron, then 4.98 x 10^-23 mol of chlorine reacts with (4.98 x 10^-23) x (2/3) = 3.32 x 10^-23 mol of iron.

No. of iron atoms = 3.32 x 10^-23 x 6.02 x 10^23 = 20

Hence C.)20