Question

what volume of a 0.716 m kbr solution is needed to provide 25.5 g of kbr? 35.7 ml 14.7 ml 299 ml 0.299 ml 153 ml

Answer 1

`\huge{ \boxed{299 \: ml}}`

Step-by-step explanation:

The volume of KBr required can be found by using the formula;

`v = (m)/(M * c)`

c is the concentration in M , mol/dm³ or mol/L

v is the volume in L or dm³

m is the mass in grams

M is the molar mass in g/mol

From the question;

m = 25.5 g

c = 0.716

Molar mass (M) of KBr = 39 + 79.9 = 118.9 g/mol

`\therefore \: v = (25.5)/(118.9 * 0.716) \\ = 0.299 \: l \\ \\ \text{but} \: 1 \: l \: = 1000 \: ml \\ \therefore0.299l \: = (0.299)/(1) * 1000 \: ml \\ = 299 \: ml \\ \therefore \: v = 299 \: ml`