I would get a container and weigh it. Then I would put the bouncy balls in the container and weigh it again. Then I would Subtract the weight of the container without the bouncy balls from the container with the bouncy balls.
It is very important that the 2.5 M HCl can be added dropwise, slowly and carefully in order to make a good mixture.
<h3>Why HCl can be added dropwise, slowly and carefully?</h3>
Hydrochloric acid can be added in the solution dropwise and slowly in order to mix with the solution very well. This acid should also be mixed with the solution carefully.
This is because hydrochloric acid is a strong acid which can damaged the skin if it is not carefully pour into the solution so we can conclude that HCl can be added dropwise, slowly and carefully is very important in order to make a good mixture.
Learn more about mixture here: brainly.com/question/24647756
The sand to pass through, but not the gravel. Hope this helps!