The correct option is B.
Stars live out most of their lives at MAIN SEQUENCE. Stars generally are divided into three major stages, these are:
1. Pro stars and pre-main sequence star
2. Main sequence and giant star
3. Variable stars
Major stages in the life of a star can last for millions of years.
I am pretty sure your answer are correct , from what I know. Good job!
PH of acidic buffer = pKa + log [CH₃COONa - HCl] / [CH₃COOH + HCl]
pKa of CH₃COOH = 4.74
Concentration of acetic acid in buffer = 2.0 M
Concentration of sodium acetate = 1.0 M
Concentration of HCl must add = x
pH = 4.74 + log (1-x) / (2+x) = 4.11
x = concentration of HCl must be added = 0.43 M
number of moles of HCl = M * V = 0.43 * 1 = 0.43 mol
mass of HCl must be added = 0.43 * 36.5 = 15.7 g
The physical properties of water is that it is clear, it has no taste. No odour. It freezes at 0 degrees Celsius and boils at 100 degrees Celsius. The different stages of water is liquid, solid and gas. It is liquid at normal state. Ice when solid and steam when it is a gas state.
It is essential for human life because majority of the human body is made out of water. The water in the body allows certain parts and organs to function properly. Without water humans are most like to become I’ll and even dehydrate causing major injuries. It is also essential for the brain to function
Answer: 
for the reaction is 5.55
Explanation:
Equilibrium constant is the ratio of the concentration of products to the concentration of reactants each term raised to its stochiometric coefficients.
The given balanced equilibrium reaction is,
At eqm. conc. (0.010) M (0.15) M (0.37) M
The expression for equilibrium constant for this reaction will be,
![K_c=\frac{[Cl_2]\times [PCl_3]}{[PCl_5]}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%5BCl_2%5D%5Ctimes%20%5BPCl_3%5D%7D%7B%5BPCl_5%5D%7D)
Now put all the given values in this expression, we get :
Thus the for the reaction is 5.55
