act science basic problem quesion. need help.

Test Preparation ACT Preparation
1

The passage says
A student decided to perform a titration experiment to neutralize a HCI solution. 50 mL of a 3mmole/mL HCI solution was poured into a beaker and placed under a buret…

The problem:
Based on the passage, if 100mL of HCI was used instead of 50mL, how many mmole of HCI would be present in the beaker before the start of the titration?

A. 3mmole
B. 50mmole
C. 100mmole
D. 300mmole

The answer is D.

I do not understand what the question is asking.
50mL - 3mmole
100mL should be 300mmole ?

help please!

2

It looks like a basic ratio question. Since the solution is 3mmole/mL, it means that there will be 3mmole for every 1 mL. So since you are using 100 mL, there should be 300mmole. 3 x 100 = 300
@actperfectgoal

3

^Correct. When the experiment was conducted with 50 mL, there were 150 mmole of HCI.