In a reaction, 25 g of reactant AB breaks down into 10g of Product A and an unknown amount of Product B. What is the mass of product B?

Mass of product B  = 15g

Explanation:

Reaction:

          AB →  A   +   B

Mass of AB  = 25g

Mass of A = 10g

Unknown:

Mass of B = ?

Solution:

Based on the law of conservation of matter "matter is neither created nor destroyed but transformed from one form to another in a chemical reaction".

 The amount of product  = amount of reactant

  Mass of AB  = Mass of A + Mass of B

  Now;

    Mass of Product B  = Mass of AB  - Mass of A

     Mass of product B   = 25  - 10  = 15g

Mass of product B  = 15g

the answer is c) gamma rays

hope i : )

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.