An 18-g sample of element A combines completely with a 4-g sample of element B to form the compound AB. What is the mass of the compound formed?

22g

Explanation:

Given parameters:

Mass of element A = 18g

Mass of element B  = 4g

Unknown:

Mass of compound formed = ?

Solution:

 The reaction equation is given as;

          A   +   B   →  AB

According to the law of conservation of mass "in a chemical reaction, matter is neither created nor destroyed but changed from one form to another".

Simply mas is conserved and the mass of the reactants is the same as the mass of the product that forms.

  Mass of reactants  = mass of A + mass of B = 18g + 4g  = 22g

 So;

  Mass of product AB = 22g

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.