Question

Calculate the number of molecules in 6.4g of sulphur (iv)oxide. (B)1.5 mole of hydrogen chloride

Answer 1

[AI-generated answer — Explain Bot]

To calculate the number of molecules in a given amount of a substance, we need to use the concept of Avogadro's number. Avogadro's number is defined as 6.022 × 10^23, and it represents the number of particles (atoms, molecules, or ions) in one mole of a substance.

To find the number of molecules in a certain mass of a substance, we need to follow these steps:

Step 1: Determine the molar mass of the substance
The molar mass represents the mass of one mole of a substance and is expressed in grams. To calculate the molar mass, we need to add up the atomic masses of each element in the chemical formula.

For sulfur (S), the atomic mass is 32.06 g/mol.
For oxygen (O), the atomic mass is 16.00 g/mol.

So, the molar mass of sulfur dioxide (SO2) is:
(1 × sulfur atomic mass) + (2 × oxygen atomic mass) = (1 × 32.06 g/mol) + (2 × 16.00 g/mol) = 64.12 g/mol

Step 2: Convert the given amount to moles
Given that we have 6.4g of sulfur dioxide, we need to convert this mass to moles using the molar mass calculated in step 1.

Number of moles = Mass / Molar mass
Number of moles = 6.4g / 64.12 g/mol
Number of moles = 0.10 mol

Step 3: Use Avogadro's number to find the number of molecules
Now that we have the number of moles, we can use Avogadro's number to find the number of molecules.

Number of molecules = Number of moles × Avogadro's number
Number of molecules = 0.10 mol × 6.022 × 10^23 molecules/mol
Number of molecules = 6.022 × 10^22 molecules

Therefore, there are approximately 6.022 × 10^22 molecules in 6.4g of sulfur (IV) oxide.

Now, let's calculate the number of molecules in 1.5 moles of hydrogen chloride (HCl).

Step 1: Determine the molar mass of the substance
For hydrogen (H), the atomic mass is 1.01 g/mol.
For chlorine (Cl), the atomic mass is 35.45 g/mol.

So, the molar mass of hydrogen chloride (HCl) is:
(1 × hydrogen atomic mass) + (1 × chlorine atomic mass) = (1 × 1.01 g/mol) + (1 × 35.45 g/mol) = 36.46 g/mol

Step 2: Convert the given amount to moles
Given that we have 1.5 moles of hydrogen chloride, we don't need to perform any conversion.

Step 3: Use Avogadro's number to find the number of molecules
Number of molecules = Number of moles × Avogadro's number
Number of molecules = 1.5 mol × 6.022 × 10^23 molecules/mol
Number of molecules = 9.033 × 10^23 molecules

Therefore, there are approximately 9.033 × 10^23 molecules in 1.5 moles of hydrogen chloride.