Question

I need help with this question... phenobarbital elixir contains 2 grams in 1 liter of elixir. How many milligrams of phenobarbital are contained in 1 teaspoon of elixir?

Answer 1

9.86 milligrams

Explanation:

It is given that 1 liter f elixir contains 2 grams of phenobarbital elixir.

Since 202.884 teaspoons = 1 liter

so 1 teaspoon of elixir =
`(1)/(202.884)` liter

∵ 1 liter of elixir contains phenobarbital = 2 gms.

∴
`(1)/(202.884)` liter of elixir contains phenobarbital =
`(2*1)/(202.884)` = 0.009858 grams

or 0.009858 × 10³ milligrams

= 9.86 milligrams.

Therefore, 9.86 milligrams of phenobarbital will be required.

Answer 2

To solve this problem, all we need is the conversion factor.

We know that there are:

1 liter = 202.884 teaspoons

Therefore the mass of Phenobarbital is:

mass = (2 grams / 1 Liter) * (1 teaspoon) * (1 Liter / 202.884 teaspoons)

mass = 0.00986 g = 9.86 x 10^-3 g = 9.86 mg