Question

How many ml of a 6.00M HNO would be required to prepare 200ml of a 2.50M

solution?
83.33ml
72.98ml
86.23ml
64.98ml

Answer 1

83.33ml

Step-by-step explanation:

Firstly, let's notice that 200ml are equal to 0.2L

M=number of moles of the solute ÷ number of liters. Let's call the number of liter by x:

2.5=x÷0.2

x=2.5×0.2

x=0.5

It means you'll need 0.5 mol of HNO. But your solution have 6 moles per liter, so how much do you need? Divide the moles by 12 to have 0.5, so now you need to divide the liter per 12 too. The liter is equal to 1000ml, so:

1000ml÷12=83.33ml