A mixture of C3H8C3H8 and C2H2C2H2 has a mass of 2.8 gg . It is burned in excess O2O2 to form a mixture of water and carbon dioxide that contains 1.4 times as many moles of CO2CO2 as of water.

Find the mass of C2H2C2H2 in the original mixture.

Express your answer to two significant figures and include the appropriate units.