A sunscreen preparation contains 2.60 % by mass benzyl salicylate. If a tube contains 6.0 oz of sunscreen, how many kilograms of benzyl salicylate are needed to manufacture 350 tubes of sunscreen?

As we are given that a sunscreen preparation contains 2.60 % by mass benzyl salicylate. That means, 2.60 grams of benzyl salicylate present in 100 g of solution.

First we have to convert the given mass from oz into kg.

Conversion used:

1 kg = 35.274 oz

or,

[tex]1oz=\frac{1}{35.274}kg[/tex]

So,

[tex]6oz=\frac{6oz}{1oz}\times \frac{1}{35.274}kg=0.1701kg[/tex]

Now we have to determine the mass of benzyl salicylate.

As, 100 g of solution contains mass of benzyl salicylate = 2.60 g

So, 0.1701 kg of solution contains mass of benzyl salicylate = [tex]\frac{2.60g}{100g}\times 0.1701kg=0.00442kg[/tex]

Now we have to determine the mass of benzyl salicylate are needed to manufacture 350 tubes of sunscreen.

Mass of benzyl salicylate in 350 tubes of sunscreen = 0.00442 kg × 350

Mass of benzyl salicylate in 350 tubes of sunscreen = 1.55 kg

Thus, the mass of benzyl salicylate needed to manufacture 350 tubes of sunscreen are, 1.55 kg