Answer:
carbon dioxide is a gas so it isn't collected over water.
Explanation:
it works for insoluble gases such as hydrogen,or gases that do not dissolve easily in water such as ammonia and chlorine are readily soluble in water and are not collected this way.
hope it is helpful for you.
Answer:

Explanation:
Hello,
In this case, since in a dilution process the moles of the solute must remain unchanged, we use the volumes and molarities as shown below:

Clearly, the concentrated solution is 12M and the diluted solution is 0.5 M, thus, the volume of the concentrated solution we should take is:

Best regards.
Answer:
A) IV: number of hours DV: score
Explanation:
Coz,
IV- is the variable that u change
DV- is the variable that u test or measure
In this case, we need to change the hours of studying to see how studying for different hours [1 hr, 2hr, etc (( Independant variable coz we're changing the no. of hours)) ] is going to affect the student's score, and in the end, we are measuring the score of each student [this is the dependant variable].