Determine the mass of 840 cm3 of oxygen gas, O2 at rtp

Mass = 0.96 g

Explanation:

Given data:

Volume of oxygen = 840cm³

Temperature = at room = 25°C

Pressure = at room = 1 atm

Mass of oxygen = ?

Solution:

Volume of oxygen = 840 cm³ × 1 L /1000 cm³ = 0.84 L

Temperature  = 25 +273.15k = 298.15 K

Formula:

PV = nRT

n = PV/RT

R = 0.0821 atm.L/mol.K

n = 1 atm × 0.84 L / 0.0821 atm.L/mol.K ×  298.15 K

n = 0.84 atm.L / 24.48 atm.L/mol

n = 0.03 mol

Mass of oxygen:

Mass = number of moles × molar mass

Mass = 0.03 mol × 32 g/mol

Mass = 0.96 g

the answer is c. nacl