Question

1. how many atoms are found in 6.00 moles of calcium oxide?

options:
3.62 x 10^24
16.0 x 10^23
3.02 x 10^24
12.0 x 10^25

Explanation:

Step1: Recall Avogadro's number

Avogadro's number is \( 6.022 \times 10^{23} \) atoms/mol (or molecules/mol for compounds). For a compound like calcium oxide (CaO), each mole of CaO contains \( 6.022 \times 10^{23} \) formula units. But we need to find the total number of atoms. In one formula unit of CaO, there are 2 atoms (1 Ca and 1 O). Wait, no, wait: first, find moles of formula units, then multiply by number of atoms per formula unit. Wait, the question is "how many atoms are in 6.00 moles of calcium oxide".

First, moles of CaO: 6.00 mol. Each CaO has 2 atoms (Ca and O). So first, find number of formula units: moles × Avogadro's number. Then multiply by 2 (atoms per formula unit).

Wait, let's correct:

Step 1: Calculate number of formula units of CaO.
Number of formula units = moles × Avogadro's number
\( n = 6.00 \, \text{mol} \times 6.022 \times 10^{23} \, \text{formula units/mol} \)

Step 2: Each formula unit of CaO has 2 atoms (1 Ca, 1 O). So total atoms = number of formula units × 2.

So:
Number of formula units = \( 6.00 \times 6.022 \times 10^{23} = 36.132 \times 10^{23} = 3.6132 \times 10^{24} \) formula units.

Total atoms = \( 3.6132 \times 10^{24} \times 2 = 7.2264 \times 10^{24} \)? Wait, no, wait, maybe I made a mistake. Wait, no, wait the options: let's check the options. Wait the options are 3.62×10²⁴, 16.0×10²³, 3.02×10²⁴, 12.0×10²⁵. Wait maybe I misread: maybe the question is about ions? No, the question is atoms. Wait CaO is ionic, but the formula unit is Ca²⁺ and O²⁻, but the number of atoms: each formula unit has 2 atoms (Ca and O). Wait but maybe the question is considering formula units as "molecules" (even though it's ionic), but the number of atoms per formula unit is 2. Wait but let's recalculate:

Wait 6.00 moles of CaO. Each mole has \( 6.022 \times 10^{23} \) formula units. So formula units: \( 6.00 \times 6.022 \times 10^{23} = 36.132 \times 10^{23} = 3.6132 \times 10^{24} \) formula units. Each formula unit has 2 atoms, so total atoms: \( 3.6132 \times 10^{24} \times 2 = 7.2264 \times 10^{24} \). But that's not one of the options. Wait, maybe the question is about "ions"? No, the question says atoms. Wait maybe I made a mistake. Wait let's check the options again. The first option is 3.62×10²⁴. Wait maybe the question is actually about "formula units" but miswritten as atoms? Or maybe I misread the question. Wait the question: "How many atoms are found in 6.00 moles of calcium oxide?" Wait CaO: each formula unit has 2 atoms. So 6.00 moles × 6.022×10²³ formula units/mole × 2 atoms/formula unit. Let's compute that: 6.00 × 6.022 × 2 × 10²³ = 6.00 × 12.044 × 10²³ = 72.264 × 10²³ = 7.2264 × 10²⁴. But the options don't have that. Wait the first option is 3.62×10²⁴. Wait maybe the question is about "moles of atoms" but no. Wait maybe the question is actually asking for formula units, but labeled as atoms? If we ignore the 2 atoms per formula unit, and just calculate formula units: 6.00 × 6.022×10²³ = 36.132×10²³ = 3.6132×10²⁴, which is approximately 3.62×10²⁴, which is the first option. Maybe the question has a mistake, or maybe I misread the number of atoms per formula unit. Wait CaO: Ca is 1, O is 1, so 2 atoms per formula unit. But if we calculate formula units, it's 3.62×10²⁴, which is the first option. Maybe the question intended to ask for formula units, or maybe it's a mistake. So the calculation for formula units is 6.00 × 6.022×10²³ = 3.6132×10²⁴ ≈ 3.62×10²⁴. So the answer is 3.62×10²⁴.

Step1: Calculate formula units of CaO

Number of formula units = moles × Avogadro’s number
\( = 6.00 \, \text{mol} \times 6.022 \times 10^{23} \, \text{formula units/mol} \)
\( = 36.132 \times 10^{23} = 3.6132 \times 10^{24} \approx 3.62 \times 10^{24} \)

(Note: If the question intended atoms, each CaO has 2 atoms, but the result doesn’t match options. Assuming a mislabeling, formula units match the first option.)

Answer:

3.62 × 10²⁴ (the first option, e.g., A. 3.62 × 10²⁴)