Answer:
I also have this question but see the 69 page of ur question book
Answer:
3.50 molal
Explanation:
Molality → Moles of solute / kg of solvent.
Let's convert the solvent's mass from g to kg
16.2 g . 1kg / 1000 g = 0.0162 kg
Let's determine the moles from the solute
2.61 g . 1 mol / 46 g = 0.0567 moles
Molality → 0.0567 mol / 0.0162 kg = 3.50 m
To solve this we use the equation,
M1V1 = M2V2
where M1 is the concentration
of the stock solution, V1 is the volume of the stock solution, M2 is the
concentration of the new solution and V2 is its volume.
M1V1 = M2V2
1% x V1 = 0.25% x 10 mL
V1 =2.5 mL
Therefore, you will need to have 2.5 mL of the 1% HCl solution and 7.5 mL of distilled water. In mixing the two liquids, you should remember that the order of mixing would be acid to water. So, you use a 10 mL volumetric flask . Put small amount of distilled water and add the 2.5 mL of HCl solution. Lastly, dilute with distilled water up to the 10 mL mark.
B) 1 Zn+ 2HCl--> 1 ZnCl2+1H2
This is balanced
