2Particle Model Changes StateMedium1 mark
An experiment is set up as shown.
The concentrated hydrochloric acid gives off hydrogen chloride gas, HCl, which dissolves in water to form an acid.
The concentrated ammonia gives off ammonia gas which dissolves in water to form an alkali.
Which row describes and explains the first change in the universal indicator paper?
| colour of universal indicator paper | reason | |
|---|---|---|
| A | blue | molecules of ammonia move more quickly than molecules of hydrogen chloride |
| B | red | molecules of ammonia move more quickly than molecules of hydrogen chloride |
| C | blue | molecules of hydrogen chloride move more quickly than molecules of ammonia |
| D | red | molecules of hydrogen chloride move more quickly than molecules of ammonia |