Question

Question #e8863

Answer 1

The volume of 0.00988 moles of Oxygen @ STP = 224.5 ml

Explanation:

Since the condition is at STP, therefore the value of P = 0.98692 atm, T= 273.15 K and the R = 0.0821 li- atm/mole-K. The no. of moles of Oxygen is given as 0.00988 moles.

Using the Ideal Gas Law:

PV = nRT , divide both sides by P to isolate the V
V = nRT/P, the desired formula, then substitute the given data
V = {0.00988`cancel(mol)`}{0.0821 li-`cancel(atm)`/(`cancel(mol)`-`cancel(K)`}{273.15`cancel(K)`}/{0.98692`cancel(atm)`}
V = 0.2215519 li/0.98692
V = 0.2244882 li, convert to ml
V = 224.5 ml, the volume of 0.00988 moles of Oxygen at STP

Answer 2

The volume of oxygen gas is `"224 mL"`.

Explanation:

`"STP"` is `"273.15 K"` and `"100 kPa"`.

Use the ideal gas law to answer this question. The equation for the ideal gas law is `"PV=nRT"`.

Given/Known
`P="100 kPa"`
`T="273.15 K"`
`n="0.00988 mol"`
`R="8.3144598 L kPa K"^(-1) "mol"^(-1)"`

Unknown
Volume in mL

Solution
Rearrange the equation to isolate `V` and solve. Then multiply the volume in liters times 1000 to get mL.

`V=(nRT)/(P)`

`V=((0.00988cancel"mol")xx(8.3144598"L" cancel"kPa" cancel("K"^(-1)) cancel("mol"^(-1)))xx(273.15cancel"K"))/(100cancel"kPa")="0.224 L"`

Convert 0.224 L to mL

`0.224"L"xx(1000"mL")/(1"L")="224 mL"`