A280 ml bubble contains 0.283 g of a gas at 0.951 atm and 25.0°c what is the molar mass of this gas?

28.3 g/mol

Explanation:

According to the ideal gas equation:'

P= Pressure of the gas = 0.951 atm

V= Volume of the gas = 280 mL = 0.28 L     (1L=1000 ml)

T= Temperature of the gas = 25°C=(25+273)K=298 K   (0°C = 273 K)

R= Value of gas constant = 0.0821 Latm/K mol

To calculate the moles, we use the equation:

Thus the molar mass of the gas is 28.3 g/mol.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.