How many moles of oxygen

Question

How many moles of oxygen are in 2.5 moles of tantalum (II) hydroxide Ta(OH)2?

Answer 1

This is called "STOICHIOMETRY" and is a strange word for a basic UNIT CANCELLATION problem! This is just like figuring out how HOW MANY SECONDS OLD ARE YOU? Just converting from 1 unit to another through association. For example;

If you are 15 yrs x (365days/1 yr) the unit, "years" cancels out leaving "days", now multiply this by the conversion "24hours/1day" so the "days are now =1 (which drops out of the equation since ANYTHING DIVIDED BY ITSELF = 1, EVEN WORDS day/day = 1, which is exactly what we are doing)! Now multiply this conversion"60 minutes/1 hr" to cancel the "hr", and finally convert "60 seconds/1 minute" canceling the "minutes" = 2.59 x 10^12 seconds! Man, that's a LOOONG TIME!

SO we take notice that the "molecular formula" for Tantalum II hydroxide, "Ta(OH)2" and notice that the "(OH)" group has a subscript 2 meaning that there are 2 OH groups, both bonded to the central tantalum atom, meaning that there are 2 OXYGEN ATOMS PER molecule of Tatalum II hydroxide!

SO, if we were going to MAKE this "cake", we would need,

1 mole of Ta atoms

2 moles O atoms

2 moles of H atoms

so then, if you more than DOUBLE this with 2.5 MOLES Ta(OH)2 that means that you need;

2.5 moles x 1 Ta = 2.5 moles Ta

2.5 moles x O x 2 = 5 moles Oxygen!

2.5 moles x H x 2 = 5 moles Hydrogen