A chemist needs 15.0 grams of ethanol for a reaction. If the density of ethanol is 0.789 g/ml, how many milliliters of alcohol should be used

Question

help, how i am going to convert it to units

Answer 1

Solution:

The reaction requires 15 g of the ethanol alcohol

The Density of ethanol is 0.789 g/ml where Density = Mass(g) / Volume(ml) so if you rearrange the equation it becomes Volume( ml) = Mass (g) / Density ( g/ml) . By substitution

The required Volume( ml) = 15 g / 0.789 g/ml = 19.01 ml

P.S. You do not need to convert units as ml is a unit of volume that can also be expressed in cubic meter

and 1 m³ = 1000 liter = 1000000 ml = 1 x10⁶ ml

Answer 2

It is important to learn how to use conversion factors. When you are given the density of alcohol as 0.789 g/mL, you are saying that 1 mL of alcohol has a mass of 0.789 g, so this can be written 1 mL = 0.789 g. This can be used as a conversion factor by forming the ratio of 1 mL / 0.789 g. We then multiply this ratio by the number of grams of alcohol given like this

1 mL / 0.789g x 15.0 g = 19.0 mL Note that the gram units cancel as they are in both the numerator and denominator, leaving only mL as the final unit.

This procedure can also be used to calculate the number of grams of alcohol in a given volume of alcohol by using the inverted form of the conversion factor ratio, 0.789g / 1 mL and then multiplying by the number of mL given in the problem. The ratio should be written so that the quantity to be found is in the numerator,