Answer:
7.35 - 7.45
Explanation:
The pH scale ranges from 0 (strongly acidic) to 14 (strongly basic or alkaline). A pH of 7.0, in the middle of this scale, is neutral. Blood is normally slightly basic, with a normal pH range of about 7.35 to 7.45. Usually, the body maintains the pH of blood close to 7.40.
Hope this helps
1) We apply the ideal gas equation:
PV = nRT
n = (21300 x 3/1000) / (8.314 x 323)
n = 0.024
Your answer is correct.
2) Total pressure = Partial pressure of Hydrogen + Partial pressure of water
134.7 = 122.4 + Pw
Pw = 12.3 kPa
Your answer is correct
3) The molar fraction, volume fraction and pressure fraction of gasses are the same thing.
Thus, percentage pressure of Oxygen = 10%
Pressure of Oxygen = 2.04 x 10⁴ x 0.1
= 2.04 x 10³ kPa
Your answer is correct
Well done!
The correct option is B.
Phenophtalein is an indicator that is usually used in acid base titration experiments. Indicators are substances that undergo distinct, observable changes when the pH of their solutions change. Indicators exhibit changing of colors depending on the pH of the solution in which they are found. They are usually weak bases and acid which are capable of partial dissociation and formation of ions when dissolved in water. There are different types of indicator and phenophtalein is one of them. Phenophtalein is colorless in acidic solution and pink in basic solutions.
Answer : Salt is more soluble in an acidic solution than in an neutral solution.
Explaination : In an acidic solution molecules of salt are assaociated with hydrogen bonding whereas in neutral solutions it molecules are not assaociated with hydrogen bonding. Acidic solution is a type of solution which has higher concentration of hydrogen ions than water is called acidic solution for ex: water.
Neutral solution is a solution which has a pH of 7,it is neither acidic nor basic but it is middle so that is called neutral solution.
Answer : The balanced chemical equation is,
The coefficient for 
is, 4 and on reactant side of the equation 
is present.
Explanation :
Rules for the balanced chemical equation in basic solution are :
- First we have to write into the two half-reactions.
- Now balance the main atoms in the reaction.
- Now balance the hydrogen and oxygen atoms on both the sides of the reaction.
- If the oxygen atoms are not balanced on both the sides then adding water molecules at that side where the more number of oxygen are present.
- If the hydrogen atoms are not balanced on both the sides then adding hydroxide ion
at that side where the less number of hydrogen are present. - Now balance the charge.
The half reactions in the basic solution are :
Reduction : 
......(1)
Oxidation : 
.....(2)
Now multiply the equation (1) by 2 and then added both equation, we get the balanced redox reaction.
The balanced chemical equation in a basic solution will be,
Thus, the coefficient for is, 4 and on reactant side of the equation is present.
