chemistry find mass

Question

i am so confused why i find two different answers while i did in two different ways!

 

I have 60ml 1M HCL    The question asks me to find the mass of HCl.

 

1. m=0.06L*(1mol / 1L)*(36.458g/mol) = 2.18748g

2. m=density*volume= 1g/cm3*60ml= 60g

 

I DON'T KNOW WHAT WRONG WITH IT. NEED HELP!

 

 

Answer 1

1. It is correct.

 

2. It can work if you convert mole density to mass density. The density here means the density of HCl, not the density of water. Here is the work:

1M of HCl = (36.458g/L) of HCl

So,

density*volume = (36.458g/L)(0.06 L) = 2.18748 g of HCl

Answer 2

1 M Hcl solution contain 1 mole of Hcl in one liter solution ..

that mean nearly 36.5 gm of Hcl is dessolve in 1 liter(1000ml) solution

 

then  grm of Hcl in 6o ml solution...=60*36.5 =2190 gm/1000 =2.190 gm of Hcl in 60 ml 1M solutiion.

 

 

Answer 3

Your calculation in 1. is right.

 

In 2. you are calculating the mass of the entire 60 mL aqueous solution, most of which is just water. Its density is a little higher than that of water, depending on the concentration. For this low concentration (3%), you can safely use 1 g/cm³.

Answer 4

Who said that density of HCL solution is 1?