Answer:
<h3>The answer is option B</h3>
Explanation:
To calculate the number of atoms we must first calculate the number of moles
Molar mass = mass / number of moles
number of moles = mass / Molar mass
Molar mass (K) = 39.10mole
mass = 2.10g
number of moles = 2.10/ 39.10
= 0.0537mol
After that we use the formula
N = n × L
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10^23 entities
Number of K atoms is
N = 0.0537 × 6.02 × 10^13
<h3>N = 3.23×10^22 atoms of K</h3>
Hope this helps you.
There is 103 percent of water in hydrate
<span>You use the Henderson - Hasselbalch equation
pH = pKa + log ([salt]/[acid])
pKa = -log (8.2*10^-5) = 4.081
pH = 4.081 + (0.590/0.190)
pH = 4.081 + log 3.105
pH = 4.081 + 0.49206
pH = 4.573</span>
