In order to understand how this equation is derived and why it holds true, the product of each side of the equation should be examined. What value and unit do you get when you multiply a concentration of 0.768 M by a volume of 0.400 L ? This question can be expressed as:
0.400L/1 x 0.768 mol/L =

Express you answer to three significant figures with appropirate units.

M1V1 =

0.307 mol

Explanation:

From the given question above, we are trying to obtain the number of mole.

The data obtained from the question include:

Molarity (M) = 0.768 M = 0.768mol/L

Volume (V) = 0.400 L

Number of mole =?

Molarity is simply the mole of solute per unit litre of the solution. It is represented mathematically as:

Molarity(M) = number of mole (n)/Volume(V)

M = n/V

If make n the suject of the formula by cross multiplying, we'll have n to be:

n = MV

Now, imputing the values of M and V from the question, we obtained:

n = 0.768mol/L x 0.400 L

Notice how the unit will cancel out i.e 'L' will cancel out 'L' leaving 'mol' as the standing unit

n = 0.307 mol

it is the most commonly accepted one