Answer:
The answer I would go with is A formation of a new substance.
Explanation:
This is because physical change includes changes of state. Some could be changing from a liquid to gas or solid to gas. B is not even an answer that should be considered because it doesn't fit into the category. C and D represents some of the examples of the process of physical change. Like boiling, bubbling, melting, or freezing. So the best would be A.
The change in pH of a 1.00 L of a buffered solution preparing by mixing 0.50 M acetic acid (Ka = 1.8 x 10^-5) and 0.50 M sodium acetate when 0.010 mole of NaOH is added is 4.75
when the same amount 0.010 mole of NaOH was added to 1.00 L of water the pH = 12
Explanation:
given that:
concentration of acetic acid = 0.50 M
Concentration of base sodium acetate = 0.50 M
ka = 1.8 x 10^-5)
pka = -log [ka]
pka = 4.74
From Henderson-Hasselbalch Equation:
pH = pKa + log ![\frac{[base]}{[acid]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D)
pH = 4.74 + Log ![\frac{[0.5]}{[0.5]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5B0.5%5D%7D%7B%5B0.5%5D%7D)
pH = 4.74 + 0
pH = 4.74
Number of moles of NaOH = 0.010 moles
volume 1 litre
molarity = 0.010 M
Moles of acetic acid and sodium acetate before addition of NaOH
FORMULA USED:
molarity = 
acetic acid,
0.5 = number of moles
0.5 is the number of moles of sodium acetate.
number of moles of NaOH 0.010 moles
NaOH reacts in 1:1 molar ratio with acetic acid so
number of moles in acetic acid = 0.5 - 0.010 = 0.49
number of moles in sodium acetate = 0.5 +0.010 = 0.51
new pH
pH = pKa + log ![\frac{[base]}{[acid]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D)
pH= 4.74 + log[0.51] - log[0.49]
pH= 4.75
PH of NaOH of 0.01 M (BASE)
pOH = -Log[0.01]
pOH = 2
pH can be calculated as
14= pH +pOH
pH= 14-2
pH = 12
K2S (aq) + CoCl2( aq) -----> 2KCl (aq) + CoS (s)
potassium + cobalt potassium chloride + carbonyl sulfide
sulfide chloride
carbonyl sulfide :- it is chemical compound with linear formula (OCS ) normally written as (CoS) .it does not show its structure . its is colorless flammable gas with an unpleasant odour.
Potassium chloride :- It is metal halide salt composed of potassium and chlorine. it is odorless and has white or colorless crystal appearance <span />
W*V i believe because it comes down to this :
I is the current, W is wattage V is volts and the * is the thing that represents the Amperes (i’m not 100% but this is my best)
The answer for your question is 0.27g/L