Question

Calculate the amount, mass, and number of chloride ions in 0.400 mol of magnesium chloride, MgCl2.

Answer 1

There are 0.800 moles of chloride ions in 0.400 moles of magnesium chloride, the mass of these ions is 28.36 grams, and there are 4.818 × 10^23 chloride ions.

Step-by-step explanation:

To calculate the amount, mass, and number of chloride ions in 0.400 moles of magnesium chloride, MgCl2, we follow several steps:

1. Recognize that magnesium chloride has one magnesium ion (Mg2+) and two chloride ions (Cl−) for every formula unit.
2. Determine the number of moles of chloride ions. Since there are two chloride ions for every molecule of MgCl2, for 0.400 moles of MgCl2, there are 0.800 moles of chloride ions (0.400 moles × 2).
3. Use the Avogadro's number to find the number of chloride ions. Multiplying the number of moles of chloride ions by Avogadro's number (6.022 × 1023 ions/mol) gives 0.800 moles × 6.022 × 1023 ions/mol = 4.818 × 1023 chloride ions.
4. Calculate the mass of chloride ions. The molar mass of Cl is approximately 35.45 g/mol, so 0.800 moles × 35.45 g/mol equals 28.36 grams of Cl−.

Therefore, there are 0.800 moles of chloride ions in 0.400 moles of magnesium chloride with a mass of 28.36 grams, and there are 4.818 × 1023 chloride ions.