1) Acidic - gastric juices pH 1, lemon juice pH 2.2, tomato juice pH 4.
2) Neutral - salt solution pH 7.
3) Alkaline - baking soda pH 9, bleach pH 13.
pH is a numeric scale used to specify the acidity or basicity of an aqueous solution.
When pH is less than seven (pH<7), solution is acidic.
When is equal seven (pH = 7), solution is neutral.
When pH is greater than seven (pH > 7), solution is basic.
Answer:
The standard enthalpy of formation of NOCl(g) at 25 ºC is 105 kJ/mol
Explanation:
The ∆H (heat of reaction) of the combustion reaction is the heat that accompanies the entire reaction. For its calculation you must make the total sum of all the heats of the products and of the reagents affected by their stoichiometric coefficient (number of molecules of each compound that participates in the reaction) and finally subtract them:
Enthalpy of the reaction= ΔH = ∑Hproducts - ∑Hreactants
In this case, you have: 2 NOCl(g) → 2 NO(g) + Cl₂(g)
So, ΔH=
Knowing:
- ΔH= 75.5 kJ/mol
= 90.25 kJ/mol
= 0 (For the formation of one mole of a pure element the heat of formation is 0, in this caseyou have as a pure compound the chlorine Cl₂)
=?
Replacing:
75.5 kJ/mol=2* 90.25 kJ/mol + 0 -
Solving
-=75.5 kJ/mol - 2*90.25 kJ/mol
-=-105 kJ/mol
=105 kJ/mol
<u><em>The standard enthalpy of formation of NOCl(g) at 25 ºC is 105 kJ/mol</em></u>
Answer:
Considering the half-life of 10,000 years, after 20,000 years we will have a fourth of the remaining amount.
Explanation:
The half-time is the time a radioisotope takes to decay and lose half of its mass. Therefore, we can make the following scheme to know the amount remaining after a period of time:
Time_________________ Amount
t=0_____________________x
t=10,000 years____________x/2
t=20,000 years___________x/4
During the first 10,000 years the radioisotope lost half of its mass. After 10,000 years more (which means 2 half-lives), the remaining amount also lost half of its mass. Therefore, after 20,000 years, the we will have a fourth of the initial amount.
Sodium is Highly reactive. It reacts with like everything
If It takes 60mL of 0.20M of sodium hydroxide (NaOH) to neutralize 25 mL of carbonic acid (
), then the concentration of the carbonic acid is 0.24M
The reaction between NaOH solution and is written below
Volume of NaOH, 
= 60 ml
Volume of , 
Molarity of , 
Molarity of NaOH, 
Number of moles of , 
Number of moles of NaOH, 
The mathematical equation for neutralization reaction is:
Substitute 
, , , = 60ml, and into the equation above in order to solve for 
Therefore, the concentration of the carbonic acid is 0.24M
Learn more here: brainly.com/question/25943090
