We know that the sunscreen preparation contains a 2.7% by mass of Benzyl Salicylate. From this, we will find that they need 1.559 kg of Benzyl Salicylate to make 340 tubes of sunscreen.
The initial data means that if the total mass of sunscreen is M, then the mass of Benzyl Salicylate will be 2.7% of M, or:
(2.7%/100%)*M = 0.027*M
Now, we know that a tube contains 6.0 oz of sunscreen.
Then M = 6.0oz
A tube contains:
0.027*6.0oz = 0.162 oz.
Then in 340 tubes, we will need 340 times 0.162 oz of Benzyl Salicylate, this is:
340* 0.162 oz = 55.08oz
And we want this quantity in kg.
Knowing that:
1oz = 0.028kg
Then 55.08oz is 55.08 times 0.028kg:
55.08*0.028kg = 1.559 kg
So they will need 1.559 kg of Benzyl Salicylate to make 340 tubes of sunscreen.
If you want to learn more, you can read:
https://brainly.com/question/24398363