Answer:
9.36
Explanation:
Sodium formate is the conjugate base of formic acid.
Also,

for sodium formate is 
Given that:
of formic acid = 
And, 
So,


Concentration = 0.35 M
HCOONa ⇒ Na⁺ + HCOO⁻
Consider the ICE take for the formate ion as:
HCOO⁻ + H₂O ⇄ HCOOH + OH⁻
At t=0 0.35 - -
At t =equilibrium (0.35-x) x x
The expression for dissociation constant of sodium formate is:
![K_{b}=\frac {[OH^-][HCOOH]}{[HCOO^-]}](https://tex.z-dn.net/?f=K_%7Bb%7D%3D%5Cfrac%20%7B%5BOH%5E-%5D%5BHCOOH%5D%7D%7B%5BHCOO%5E-%5D%7D)

Solving for x, we get:
x = 0.44×10⁻⁵ M
pOH = -log[OH⁻] = -log(0.44×10⁻⁵) = 4.64
pH + pOH = 14
So,
<u>pH = 14 - 4.64 = 9.36</u>
Answer: Option (4) is the correct answer.
Explanation:
A mixture is defined as a substance that contains two or more different substance that are physically mixed with each other.
If solute particles are evenly distributed in a solvent then it is known as a homogeneous mixture.
For example, salt dissolved in water is a homogeneous mixture.
If solute particles are unevenly distributed into the solvent then it is known as a heterogeneous mixture.
For example, sand in water is a heterogeneous mixture.
Thus, we can conclude that the statement a mixture must contain at least two different substances, is correct about mixtures.
Answer: There are now 2.07 moles of gas in the flask.
Explanation:
P= Pressure of the gas = 697 mmHg = 0.92 atm (760 mmHg= 1 atm)
V= Volume of gas = volume of container = ?
n = number of moles = 1.9
T = Temperature of the gas = 21°C=(21+273)K= 294 K (0°C = 273 K)
R= Value of gas constant = 0.0821 Latm\K mol
When more gas is added to the flask. The new pressure is 775 mm Hg and the temperature is now 26 °C, but the volume remains same.Thus again using ideal gas equation to find number of moles.
P= Pressure of the gas = 775 mmHg = 1.02 atm (760 mmHg= 1 atm)
V= Volume of gas = volume of container = 49.8 L
n = number of moles = ?
T = Temperature of the gas = 26°C=(26+273)K= 299 K (0°C = 273 K)
R= Value of gas constant = 0.0821 Latm\K mol
Thus the now the container contains 2.07 moles.
The answer is C as enzymes are biological catalysts that act on a substrate such as starch if the enzyme were amylase
hope that helps
Hydrogen is the only atom that does not have neutron electrons in the first energy level/shell.