Question

Imagine an experiment in which hydrogen peroxide decomposes to form water and oxygen gas. hydrogen peroxide>water+oxygen gas which of the following processes could be used to show that this reaction obeys the law of conservation of matter

A. show that the mass of water produced is more than the mass of oxygen produced
B. show that the mass of water produced plus the mass of oxygen produced are together equal to the original mass of hydrogen peroxide
C. there is no way to show that the law of conservation is supported.

2. When an acid and a base react, they form new substances compare the new products with the original substances. original substance(acid+base) > new substances

A. the chemical and physical properties of the new substances are different from the properties of the original substances

B.the chemical and physical properties of the new substance are the same as the properties of the original substances

C. The chemical properties of the new substances are the same but the physical properties are different

D. the physical properties of the new substances are the same but the chemical properties are different.

Answer 1

For #1, we can show conservation of mass stoichiometrically converting the starting amount of reactants into the final amount of products

For instance 2H2O2 —> 2H2O + O2

If we start with 70g H2O2,
our theoretical yield of H2O~ 37g
Our theoretical yield of O2~ 33g

So 70g = 37g + 33g

For #2, an Acid-base reaction always forms a salt and water. For instance,

HCl + NaOH —> H2O + NaCl

This is called neutralization and I would think that Chemical properties would be different, as well as the physical properties.