Answer:
Explanation:
It is necessary to run TLC in a closed container and have the interior saturated with the solvent vapor to ensure maximum resolution between components and to prevent solvent evaporating off. If the solvent evaporates off, the Rf value would be lower than the expected value.
<span><span>4.2×1022</span>NA</span><span> N_{A} is the avagadro number</span>
Mg will lose 2 valance electrons to obtain octet
Answer:
Explanation:
25. Boyle's Law
The temperature and amount of gas are constant, so we can use Boyle’s Law.
Data:
Calculations:
26. Ideal Gas Law
We have p, V and n, so we can use the Ideal Gas Law to calculate the volume.
pV = nRT
Data:
p = 101.3 kPa
V = 20 L
n = 5 mol
R = 8.314 kPa·L·K⁻¹mol⁻¹
Calculation:
101.3 × 20 = 5 × 8.314 × T
2026 = 41.57T
Answer:
CaCl₂
Step-by-step explanation:
The <em>empirical formula</em> is the simplest whole-number ratio of atoms in a compound.
The ratio of atoms is the same as the ratio of moles.
So, our job is to calculate the molar ratio of Ca to Cl.
Data:
Mass of Ca = 3.611 g
Mass of Cl = 6.389 g
Calculations
Step 1. <em>Calculate the moles of each element
</em>
Moles of Ca = 3.611 g Ca × (1 mol Ca/(40.08 g Ca)= 0.090 10 mol Ca
Moles of Cl = 6.389 g Cl
Step 2. <em>Calculate the molar ratio of the elements
</em>
Divide each number by the smallest number of moles
Ca:Cl = 0.090 10:0.1802 = 1:2.000
Step 3. Round the molar ratios to the nearest integer
Ca:Cl = 1:2.000 ≈ 1:2
Step 4: <em>Write the empirical formula
</em>
EF = CaCl₂