Answer: Volume of the 1M EtOH and water should be 0.75 ml and 9.25 ml respectively to obtain the working concentration.
Explanation:
According to the dilution law,
where,
= molarity of stock solution = 1M
= volume of stock solution = ?
= molarity of diluted solution = 0.075 M (1mM=0.001M)
= volume of diluted solution = 10 ml
Putting in the values we get:
Thus 0.75 ml of 1M EtOH is taken and (10-0.75)ml = 9.25 ml of water is added to make the volume 10ml.
Therefore, volume of the 1M EtOH and water should be 0.75 ml and 9.25 ml respectively to obtain the working concentration
Answer:
The concentration the student should write down in her lab is 2.2 mol/L
Explanation:
Atomic mass of the elements are:
Na: 22.989 u
S: 32.065 u
O: 15.999 u
Molar mass of sodium thiosulfate, Na2S2O3 = (2*22.989 + 2*32.065 + 3*15.999) g/mol = 158.105 g/mol.
Mass of Na2S2O3 taken = (19.440 - 2.2) g = 17.240 g.
For mole(s) of Na2S2O3 = (mass taken)/(molar mass)
= (17.240 g)/(158.105 g/mol) = 0.1090 mole.
Volume of the solution = 50.29 mL = (50.29 mL)*(1 L)/(1000 mL)
= 0.05029 L.
To find the molar concentration of the sodium thiosulfate solution prepared we use the formula:
= (moles of sodium thiosulfate)/(volume of solution in L)
= (0.1090 mole)/(0.05029 L)
= 2.1674 mol/L
Answer:
collide less often and with less force
Answer:
1. Dynamic equilibrium is a equilibrium in which the rate of forward direction is equal to the rate of backward direction. It is represented by a right left arrow.
2) Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as 
For the given chemical reaction:
![Fe^{3+}(aq)+SCN^-(aq)\rightleftharpoons [Fe(SCN)]^{2-}(aq)](https://tex.z-dn.net/?f=Fe%5E%7B3%2B%7D%28aq%29%2BSCN%5E-%28aq%29%5Crightleftharpoons%20%5BFe%28SCN%29%5D%5E%7B2-%7D%28aq%29)
The expression for is written as:
![K_c=\frac{[[Fe(SCN)]^{2-}]}{[Fe^{3+}][SCN^-]}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%5B%5BFe%28SCN%29%5D%5E%7B2-%7D%5D%7D%7B%5BFe%5E%7B3%2B%7D%5D%5BSCN%5E-%5D%7D)
3) The value of is 1000 , which means the products are more favoured as compared to reactants and that the equilibrium lies more towards product side.
