Question

what is the relative formula mass of phosphate (PO4)? (To the nearest tenth) A. 187.9 grams B. 46.9 grams C. 23.0 grams D. 94.9 grams

Answer 1

`\huge \boxed{\mathrm{D. \ 94.9 \ grams}}`

Step-by-step explanation:

Phosphate chemical formula is given as,

`\sf PO_4`

There is one phosphorus atom and four oxygen atoms.

Atomic mass of Phosphorus
`\sf P` = 30.974 grams

Atomic mass of Oxygen
`\sf O` = 15.999 grams

`\Rightarrow 30.974 + 4(15.999)`

`\Rightarrow 30.974+ 63.996`

`\Rightarrow 94.97`

The relative formula mass of phosphate
`\sf PO_4` is 94.9 grams.

Answer 2

`\huge\boxed{94.9\ grams}`

Step-by-step explanation:

Relative formula mass of phosphate:

=>
`PO_(4)` [Ignoring the charge on it]

Atomic mass of P = 31.0 grams, O = 15.9 grams

=> 30.97 + 4(15.9)

=> 30.97 + 63.9

=> 94.87

≈ 94.9 grams [To nearest tenth]