Question

what do these two changes have in common?
adding dish soap to water in a sink
bleaching clothes
select all that apply.
both conserve mass.
both are chemical changes.
both are caused by cooling.
both are changes of state.

Explanation:

1. Both conserve mass: According to the law of conservation of mass, in any physical or chemical change, the total mass of the substances involved remains constant. Adding dish soap to water (a physical mixing, though soap may have some minor chemical interactions) and bleaching clothes (a chemical reaction) both follow this law as mass is neither created nor destroyed.
2. Both are chemical changes: Adding dish soap to water - while mixing is physical, the soap dissolving and interacting with water (and potentially grease later) involves some chemical interactions (like surfactant action). Bleaching clothes is a clear chemical change as bleach (e.g., sodium hypochlorite) reacts with stains or dyes to break their chemical structure.
3. The other options are incorrect:

• "Both are caused by cooling": Neither adding soap to water nor bleaching clothes is caused by cooling.
• "Both are changes of state": Adding soap to water doesn't change the state of matter (both are liquid), and bleaching clothes doesn't involve a change of state (clothes remain solid, bleach is liquid).

Answer:

A. Both conserve mass
B. Both are chemical changes