Answer:
11.7
Explanation:
The pH is the negative logarithm of the concentration of H+ ions. If the concentration is 2×10-¹² the the pH will be -log(2×10-¹²) which is 11.698 which can be round up to 11.7.
I think the answer is the last answer at the bottom
In order to find molarity, you must first find the number of moles that was dissolved.
Now, Moles = Mass ÷ Molar Mass
⇒ Moles of NaCl = 2.922 g ÷ 58.44 g/mol
= 0.05 moles
∴ the Molarity of the NaCl is 0.05 M [Option 1]
Answer: It takes 3.120 seconds for the concentration of A to decrease from 0.860 M to 0.260 M.
Explanation:
Integrated rate law for second order kinetics is given by:
k = rate constant = 
= initial concentration = 0.860 M
a= concentration left after time t = 0.260 M

Thus it takes 3.120 seconds for the concentration of A to decrease from 0.860 M to 0.260 M.
An endothermic chemical reactions products tend to have a higher potential energy than the reactants. Thus making the /\ H positive, not negative.