# In a scientific investigation, the term "quantitative data" refers to numbers that are usually followed by by what?

May 11, 2018

$\text{....blocks of flats....?}$

#### Explanation:

No...$\text{quantitative data}$ are always reported with the $\text{appropriate units.}$

Sometimes the use of units can help you in a chemical calculations. We know that $\text{concentration}$ has units of $\text{amount of stuff per unit volume}$...

And so for concentration, we would generally take the quotient...

$\text{Concentration"="Moles (or mass) of stuff"/"Volume of solution}$

..units of $m o l \cdot {L}^{-} 1$ apply.....

And when we want to convert a concentration term into a mass of mole quantity, given a specific volume we take the product such that WE GET UNITS of moles in the final answer...

$\text{How many moles in}$ $0.500 \cdot L$ $1.0 \cdot m o l \cdot {L}^{-} 1$ $H C l$?

${n}_{\text{HCl}} = 0.500 \cdot \cancel{L} \times 1.0 \cdot m o l \cdot \cancel{{L}^{-} 1} = 0.50 \cdot m o l$

When the units DO NOT cancel out, you know you have made a balls-up, which are all too easy to do, and why else go thru the bother of including units in our calculations? And note that this approach works for fyzics too....$F = m a$ etc...