Question

What is the mass of 2.50L of SO2 gas at stp

Answer 1

STP is abbreviation for Standard Temperature and Pressure at which the temperature is 273 K and pressure is 1 atm 
- At these conditions the molar volume is equal to 22.4 L
so 1 mole of SO₂ volume = 22.4 L 
     ? mole of SO₂ volume = 2.5 L
number of moles = 2.5 / 22.4 = 0.1116 mol
mass of SO₂ = 0.1116 * 64.063 = 7.15 g

Answer 2

Answer: 4.84 grams

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass, occupies 22.4 L of volume at STP and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given volume}}{\text{Molar volume}}=\frac{2.50}{22.4}=0.11$

1 mole of $SO_2$ weighs = 44 g

0.11 moles of $SO_2$ weigh = $\frac{44}1}\times 0.11=4.84g$

Thus mass of 2.5 L of $SO_2$ weigh 4.84 grams.