If 0.357 g of ch4 gas is introduced into an evacuated 1.75 l flask at 25°c, what is the pressure in
.08206 l atm/mol k)

P = 0.29 atm

Explanation:

Given data:

Mass of CH₄ = 0.357 g

Volume of flask = 1.75 L

Temperature = 25°C ( 25+273 = 298 K)

R = 0.08206 L. atm/K.mol

Pressure = ?

Solution:

Number of moles :

Number of moles = mass/ molar mass

Number of moles = 0.357 g /16g/mol

Number of moles = 0.02 mol

PV = nRT

P = nRT/V

P = 0.02 mol × 0.08206 L. atm/K.mol. × 298 K / 1.75 L

P = 0.5 L. atm  / 1.75 L

P = 0.29 atm

rosa was looking for patterns to predict the products of chemical reactions. she recorded three similar decomposition reactions in the table.she should record 2licl + 3o2.

in the last row of the table. it is the thermal decomposition of chlorate lithium, hence, she should record these products as: lithium chloride ( 2licl ) and oxygen ( 3o2 )   2 > 2 licl + 3o2.