Answer:
- <u>First choice: 0.042</u>
Explanation:
Given decomposition reaction:
- 1PCl₅ (g) ⇄ 1PCl₃ + 1Cl₂(g)
Equilibrium constant:
Stoichiometric coefficients and powers equal to 1 are not usually shown as they are understood, but I included them in order to shwow you how they intervene in the equilibrium expressions: each concentration is raised to a power equal to the respective stoichiometric coefficient in the equilibrium equation.
So, your calculations are:

Answer:
pI = 6.16
Explanation:
The pI is given by the average of the pKas that are involved. In this case,
Pka of carboxylic acid was given as 2.72 and that of the Amino group was given as 9.60. the average would then be ½(2.72+9.60)
= 6.16
Answer:

Explanation:
<u>1. Convert Molecules to Moles</u>
First, we must convert molecules to moles using Avogadro's Number: 6.022*10²³. This tells us the number of particles in 1 mole of a substance. In this case, the particles are molecules of sodium hydroxide.

Multiply by the given number of molecules.

Flip the fraction so the molecules cancel out.




<u>2. Convert Moles to Grams</u>
Next, we convert moles to grams using the molar mass.
We must calculate the molar mass using the values on the Periodic Table. Look up each individual element.
- Na: 22.9897693 g/mol
- O: 15.999 g/mol
- H: 1.008 g/mol
Since the formula has no subscripts, we can simply add the molar masses.
- NaOH: 22.9897693+15.999+1.008=39.9967693 g/mol
Use this as a ratio.

Multiply by the number of moles we calculated.

The moles of sodium hydroxide cancel.



The original measurement of molecules has 3 significant figures, so our answer must have the same. For the number we calculated, that is the thousandth place. The 0 tells us to leave the 7 in the hundredth place.

1.20*10²² molecules of sodium hydroxide is approximately 0.797 grams.