Question

quesrion from mole concept class 11​

Answer 1

Answer:

9) 750 ml of 0.5 M HCl have 0.375 moles.

250 ml of 2 M HCl have 0.5 moles.

Total moles =0.875moles

Total volume =750+250=1000ml=1L

Molarity = moles/Volume

. = 0.875/1

=0.875M

10.A 5.2 molal aqueous solution of methyl alcohol means that 1 kg ( or 1000 g) of water contains 5.2 moles of methyl alcohol. The molecular weight of water is 18 g/mol.

The number of moles of water

= 1000g/18 g/mol

= 55.56 mol

The mole fraction of methyl alcohol =

5.2 mol /5.2mol+55.56mol

=0.086 .