Magnesium chloride is the name for the chemical compounds with the formulas MgCl2 and its various hydrates MgCl2(H2O<span>)x. These salts are typical ionic halides, being highly soluble in water. The hydrated magnesium chloride can be extracted from brine or sea water.</span>
B. Two significant figures
Your final answer can only have as many significant figures as the number that has the least amount of significant figures in it, which is (0.0065)
Answer:
1.3×10⁻³ M
Explanation:
Hello,
In this case, given the dissociation reaction of acetic acid:
We can write the law of mass action for it:
![Ka=\frac{[H_3O^+][CH_3CO_2^-]}{[CH_3CO_2H]}](https://tex.z-dn.net/?f=Ka%3D%5Cfrac%7B%5BH_3O%5E%2B%5D%5BCH_3CO_2%5E-%5D%7D%7B%5BCH_3CO_2H%5D%7D)
Of course, excluding the water as heterogeneous substances are not included. Then, in terms of the change 
due to the dissociation extent, we are able to rewrite it as shown below:
Thus, via the quadratic equation or solve, we obtain the following solutions:
Obviously, the solution is 0.00133M which match with the hydronium concentration, thus, answer is: 1.3×10⁻³ M in scientific notation.
Regards.
Carbon dioxide consists of the elements Carbon (C) and Oxygen (O) and you have to have 2 oxygen.
Mole ratio :
<span>5 C</span>₆<span>H</span>₆<span>CHO + 2 KMnO</span>₄<span> + 6 H</span>⁺ <span>= 5 C</span>₆<span>H</span>₆<span>COOH + 2 Mn</span>²⁺<span> + 3 H</span>₂<span>O + 2 K</span>⁺
5 moles C₆H₆CHO ------------------ 2 moles KMnO₄
1.0 moles C₆H₆CHO ---------------- ( moles of KMnO₄ )
moles of KMnO₄ = 1.0 x 2 / 5
moles of KMnO₄ = 2 / 5
= 0.40 moles of KMnO4
hope this helps!
