Answer:
D, E and F
Explanation:
About tetrachloro cobalt complexes, the following facts have been observed
- Color of the tetrachloro cobalt complexes is blue.
- They do not decompose on heating that means synthesis of tetra chloro is endothermic.
About hexa aqua cobalt complexes, the following facts have been observed
- Color of the hexa aqua cobalt complexes is pink color.
- They decompose on heating and remain stable on cooling that means process of synthesis of hexa aqua cobalt complexes is exothermic.
Based on above, the correct statements are:
The correct is chloro cobalt complex is blue and aqua cobalt
complex is pink.
The chloro complex is favored by heating.
If the chloro complex is a product, then the reaction must be endothermic.
The correct options are D, E and F.
Answer: Molarity of a physiological saline solution is 0.15 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

n = moles of solute
=volume of solution in ml
Given : 0.89 g of sodium chloride in 100 ml of solution.
To calculate the moles, we use the equation:

Volume of solution = 100 ml

Molarity of physiological saline solution is 0.15 M
Reactants are what is consumed in a chemical reaction while products are what is created by the chemical reaction.
Answer:
The relative densities of an object and the liquid it is placed in determine whether that object will sink or float. An object that has a higher density than the liquid it's in will sink. An object that has a lower density than the liquid it's in will float.
Explanation:
Hope it helps!
The question is incomplete, complete question is :
Determine the pH of an HF solution of each of the following concentrations. In which cases can you not make the simplifying assumption that x is small? (
for HF is
.)
[HF] = 0.280 M
Express your answer to two decimal places.
Answer:
The pH of an 0.280 M HF solution is 1.87.
Explanation:3
Initial concentration if HF = c = 0.280 M
Dissociation constant of the HF = 

Initially
c 0 0
At equilibrium :
(c-x) x x
The expression of disassociation constant is given as:
![K_a=\frac{[H^+][F^-]}{[HF]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BH%5E%2B%5D%5BF%5E-%5D%7D%7B%5BHF%5D%7D)


Solving for x, we get:
x = 0.01346 M
So, the concentration of hydrogen ion at equilibrium is :
![[H^+]=x=0.01346 M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3Dx%3D0.01346%20M)
The pH of the solution is ;
![pH=-\log[H^+]=-\log[0.01346 M]=1.87](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BH%5E%2B%5D%3D-%5Clog%5B0.01346%20M%5D%3D1.87)
The pH of an 0.280 M HF solution is 1.87.