Question

Question #c2d91

Answer 1

Around `1.06*10^24` ions

Explanation:

`OH^-` has a molar mass of `17 \ "g/mol"`.

So, in `30 \ "g"` of hydroxide ions. there exists `(30cancel"g")/(17cancel"g""/mol")~~1.76 \ "mol"`

In one mole of molecules, there are `6.02*10^23` molecules.

So, there will be a total of

`1.76*6.02*10^23~~1.06*10^24` hydroxide ions.

Answer 2

See below

Explanation:

We know that in 1 Mole we have `6.022 * 10^23` particles.

In this situation, we aren't given the specified amount of moles, so we have to work them out using the formula:

moles `= (mass) / M_r`

Where the `M_r` is the relative formula mass.

Here we have a mass of `30` and an `M_r` of `17`

`therefore` the amount of moles we have is `30/17` moles.

To work out the number of particles, we multiply the number of moles by Avogadro's constant `(6.022 * 10^23)`

`therefore 30/17 * 6.022 * 10^23 = 1.062705882 * 10^23` ions