Which of the following solutions contains the smallest number of ions? a. 156.5 ml of 2.0 m iron(iii) chloride b. 521.4 ml of 1.0 m lithium nitrate c. 374.3 ml of 2.0 m potassium hydroxide d. at least two of the above contain the smallest number of ions. e. 297.1 ml of 1.0 m sodium sulfate

297.1 mL of 1.0 M sodium sulfate has smallest number of ions.

Explanation:

A) 156.5 mL of 2.0 M iron(III) chloride

Volume of iron(III) chloride solution = 156.5 mL = 0.1565 L

Molarity of the iron(III) chloride  = 2.0 M

Moles of iron(III) chloride = n

1 mole of  iron(III) chloride gives 1 mol ferric ion and 3 mol chloride ions.

Number of ferric ions = 0.313 mol

Number of chloride ions =  0.313 mol × 3 = 0.939 mol

Total moles of ions = 1.252 moles

B) 521.4 mL of 1.0 M lithium nitrate:

Volume of lithium nitrate solution = 521.4 mL = 0.5214 L

Molarity of the lithium nitrate  = 1.0 M

Moles of lithium nitrate  = n

1 mole of  lithium nitrate  gives 1 mol lithium ion and 1 mol nitrate ions.

Number of lithium ions = 0.5214 mol

Number of nitrate ions = 0.5214 mol

Total moles of ions = 1.0428 mol

C)  374.3 mL of 2.0 M potassium hydroxide :

Volume of potassium hydroxide solution = 374.3 mL = 0.3743 L

Molarity of the potassium hydroxide  = 2.0 M

Moles of potassium hydroxide  = n

1 mole of  potassium hydroxide  gives 1 mol potassium ion and 1 mol hydroxide ions.

Number of potassium ions = 0.7486 mol

Number of hydroxide ions = 0.7486  mol

Total moles of ions = 1.4972 mol

E) 297.1 mL of 1.0 M sodium sulfate:

Volume of  sodium sulfate solution = 297.1 mL = 0.2971 L

Molarity of the  sodium sulfate  = 1.0 M

Moles of  sodium sulfate  = n

1 mole of   sodium sulfate gives 1 mol sodium ion and 2 mol sulafte ions.

Number of sodium ions = 0.2971 mol

Number of sulfate ions = 0.2971 mol × 2 = 0.5942 mol

Total moles of ion = 0.8913 mol

Higher the number of moles more with number of ions in the solution and vice-versa.

297.1 mL of 1.0 M sodium sulfate has smallest number of ions.

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"

i think   the answer is c hope i'm right