Molarity is defined as the number of moles of solute in 1 L of solution
molarity of stock solution to be prepared - 100 x 10⁻³ mol/L
volume of stock solution to be prepared - 1.2 mL
Therefore number of moles in 1.2 mL - 100 x 10⁻³ mol/L x 1.2 x 10⁻³ L
number of moles of drug - 1.2 x 10⁻⁴ mol
mass of drug required - 1.2 x 10⁻⁴ mol x 181.6 g/mol = 21. 8 mg
21.8 g of drug is required to make the stock solution

6 0

3 years ago

Lavoviser is commonly know as the( brainly dont eveer help)

finlep [7]

Lavoisier is known as the “Father of Modern Chemistry” or the “Father of Chemistry”.

He is famous for isolating oxygen and establishing the law of conservation of mass.

6 0

3 years ago

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When dilute HCL is added to zinc pieces taken in a test tube

Romashka-Z-Leto [24]

Answer:

zince chloride will be formed and hydrogen gas will be librated.

Explanation:

When dilute HCl is added to zinc pieces, a rection will takes place as follows :

$Zn+HCl\rightarrow ZnCl_2+H_2$

It means that zinc chloride will form when zinc reacts with dilute HCL. Also hydrogen gas will produced.

As zinc is more reactive than hydrogen, it displaces hydrogen from its solution and forms zinc chloride. The form product is white in color and H₂ is an odorless gas.

Hence, zince chloride will be formed and hydrogen gas will be librated.

6 0

3 years ago