Question

In the example in the lesson, 0.10 mole of sodium chloride or magnesium chloride or aluminum chloride was added to one liter of water. How many moles of each chloride are in one milliliter of the respective solutions? Hint: There are 0.10 moles per liter. Recall how many milliliters are in a liter and divide 0.10 by that number. (Remember to use the proper number of significant figures.) moles/mL

Answer 1

0.1 mol / L * 1L/1000mL = 0.0001 mol / mL

using sigs figs

1×10^-4 mol /mL

Answer 2

Answer: The moles of chloride ions in sodium chloride is
`1* 10^(-4)` moles, in magnesium chloride is
`2* 10^(-4)` moles and in aluminium chloride is
`3* 10^(-4)` moles

Step-by-step explanation:

We are given:

Moles of sodium chloride in 1 L of solution = 0.10 moles

Moles of magnesium chloride in 1 L of solution = 0.10 moles

Moles of aluminium chloride in 1 L of solution = 0.10 moles

We need to calculate the moles of chloride ion in each solution in 1 mL of solution. The conversion factor used is:

1 L = 1000 mL

• For sodium chloride:

1 mole of NaCl produces 1 mole of sodium ions and 1 mole of chloride ions.

Moles of chloride ions in 1 L solution = 0.10 moles

Moles of chloride ions in 1 mL solution =
`(0.10)/(1000)=1* 10^(-4)` moles

• For magnesium chloride:

1 mole of
`MgCl_2` produces 1 mole of magnesium ions and 2 moles of chloride ions.

Moles of chloride ions in 1 L solution = (0.10 × 2) = 0.20 moles

Moles of chloride ions in 1 mL solution =
`(0.20)/(1000)=2* 10^(-4)` moles

• For aluminium chloride:

1 mole of
`AlCl_3` produces 1 mole of aluminium ions and 3 moles of chloride ions.

Moles of chloride ions in 1 L solution = (0.10 × 3) = 0.30 moles

Moles of chloride ions in 1 mL solution =
`(0.30)/(1000)=3* 10^(-4)` moles

Hence, the moles of chloride ions in sodium chloride is
`1* 10^(-4)` moles, in magnesium chloride is
`2* 10^(-4)` moles and in aluminium chloride is
`3* 10^(-4)` moles