What volume will 0.405 g of krypton gas occupy at STP?

The answer to your question is V = 0.108 L or 108 ml

Explanation:

Data

Volume = ?

mass = 0.405 g

Temperature = 273°K

Pressure = 1 atm

Process

1.- Convert mass of Kr to moles

                  83.8 g of Kr 1 mol

                     0.405 g      x

                     x = (0.405 x 1) / 83.8

                     x = 0.0048 moles

2.- Use the Ideal gas law to solve this problem

                   PV = nRT

- Solve for V

                      V = nRT / P

- Substitution

                      V = (0.0048)(0.082)(273) / 1

- Simplification

                       V = 0.108 / 1

- Result

                       V = 0.108 L

The volume of the krypton gas is 108.2 mL

Explanation:

Step 1: Data given

Mass of krypton = 0.405 grams

STP = 1 atm , 273 K

Atomic mass krypton = 83.80 g/mol

Step 2: Calculate moles of krypton

Moles krypton = mass krypton /molar mass krypton

Moles krypton = 0.405 grams / 83.80 g/mol

Moles krypton = 0.00483 moles

Step 3: Calculate volume of krypton gas

p*V = n*R*T

V = (n*R*T)/p

⇒with n = the moles of krypton =0.00483 moles

⇒with R = the gas constant = 0.08206 L*atm/L*mol

⇒with T = the temperature = 273 K

⇒ with p = the pressure = 1 atm

⇒ with V = the volume of the krypton gas = ?

V = 0.00483 * 0.08206 * 273

V = 0.1082 L = 108.2 mL

The volume of the krypton gas is 108.2 mL