Henry puts 2.0 grams of baking soda into a 1.0 gram plastic bag. he then pours 5.0 grams of vinegar into the bag and immediately closes it. a reaction takes place. henry observes a gas being produced, and the plastic bag with the baking soda and vinegar becomes cold to the touch. what will be the total mass of the bag and its contents after the reaction?
a)6.0 grams
b)8.0 grams
c)5.0 grams
d)7.0 grams

B)  8.0 grams

Explanation:-

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

Mass of reactants = 2.0 g + 5.0 g= 7.0 g

mass of bag = 1.0 g

Thus mass of products + mass of bag = 7.0 g + 1.0 g= 8.0 g