To solve this we use the
equation,
<span> M1V1 = M2V2</span>
<span> 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.</span>
<span>2.0 M x V1 = 0.50 M x 200 mL</span>
<span>V1 = 50 mL needed</span>
Answer
Na OH reacts with H Cl and forms Na Cl and H₂O
NaOH + HCl → NaCl + H₂O
Here we can see that 1 mole of NaOH reacting with 1 mole of HCl and forming 1 mole of NaCl and 1 mole of H₂O
when NaOH and HCl are added together in equal amount then they will completely neutralize each other but NaOH is hygroscopic in nature which means it can absorb water from air so it will not be weighted accurately.
hence, for neutralization we will take extra NaOH.
Given :
A 250 ml beaker weighs 13.473 g .
The same beaker plus 2.2 ml of water weighs 15.346 g.
To Find :
How much does the 2.2 ml of water, alone, weigh .
Solution :
Now, mass of water is given by :
Therefore , mass of 2.2 ml of water alone is 1.873 g .
Hence , this is the required solution .
<em>M CaCl₂: 40+(35,5×2) = 111 g/mol</em>
6,02·10²³ molecules ---------- 111g
X molecules --------------------- 75,9g
X = (75,9×<span>6,02·10²³)/111
X = <u>4,116</u></span><span><u>·10²³</u> molecules of CaCl</span>₂
:)
