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There are 360 drops in one tablespoon and there are 14.8 mL in one tablespoon.Calculate...

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animalover4546 | Student, Undergraduate | Honors

Posted February 15, 2013 at 3:45 AM via web

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There are 360 drops in one tablespoon and there are 14.8 mL in one tablespoon.
Calculate the number of drops in 1.0 mL.

Really having a hard time understanding how to do this..please be as detailed as possible

Tagged with chemistry, science

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Mary Joy Ripalda | High School Teacher | (Level 3) Educator

Posted February 15, 2013 at 4:29 AM (Answer #1)

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To determine the number of drops in 1.0mL, use the method of conversion of units.

In the problem, there are two conversion factors given. These are:

360 drops = 1 tablespoon          and

14.8 mL = 1 tablespoon

So, multiply 1.0mL with the second conversion factor in such a way that the unit mL cancels.

                       1 tablespoon

1.0 mL   `xx`    ----------------- `=`  0.0676  table spoon

                           14.8 mL 

Then, multiply the result with the first conversion factor. The unit tablespoon should cancel.

                                         360 drops

0.0676 tablespoon  `xx`     ----------------- `=`  24.336 drops

                                       1 tablespoon

Round-up the result to nearest whole number.

Hence, there are 25 drops in 1.0 mL.

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ahalperi | Middle School Teacher | (Level 1) Adjunct Educator

Posted February 15, 2013 at 4:47 AM (Answer #2)

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You are given two equalities  360 drops = 1 Tablespoon and 14.8 mL = 1 Tablesppon.  THere are a couple ways you can approach this.

1.) Since 360 drops and 14.8mL are each equal to a Tablespoon, you can set them equal to each other   360 drops = 14.8 mLto calculate the number of drops in 1 mL simply divide both sides of the equation by 14.8.  360 ÷ 14.8 = 14.8 ÷ 14.8 ==>  approximately 24.3 drops = 1 mL.

2. You can also use dimensional analysis and let the units guide your calculation (though it really ends up being the same calulation)

 

 360 drops               1 T                 360 drops
__________    x   _________ =  ____________   =

   1 T                      14.8 mL             14.8 mL

 

= approximately 24.3 drops/mL

(The 1 Tablespoons cancel each other out)

 

The nice thing about dimensional analysis is that it guides your work through the units which must cancel out.  Because each successive fraction has numerators equivalent to each denominator, the value is not changing but is being converted between units.

 

 

 

Sources:

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