Question

For 1 mole of each of the following, how many moles of ions are present when they are dissolved in water? (Answer choices may be used more than once.)

(NH4)2CO3

NaBr

Mg(ClO4)2

HCl

A. 1 B. 4 C. 5 D. 3 E. 2

Match them up correctly

Answer 1

1)

(NH4)2CO3 dissociates as

(NH4)2CO3 —> 2 NH4+   + CO32-

So, number of moles of ions = 3

Answer: 3

2)

NaBr dissociates as

NaBr    —> Na+       +   Br-

So, number of moles of ions = 2

Answer: 2

3)

Mg(ClO4)2 dissociates as

Mg(ClO4)2 —> Mg2+   +   2ClO4-

So, number of moles of ions = 3

Answer: 3

4)

HCl dissociates as

HCl —> H+    +   Cl-

So, number of moles of ions = 2

Answer: 2