Answer:
Nitrogen: Non- metal = they are poor conductors of heat and electricity, they are brittle solids, not ductile in their solid state - they cannot be rolled into wires or pounded into sheets. They are usually dull and therefore show no metallic luster and they do not reflect light. They also have a low density.
Aluminium: Metal= Offers a rare combination of valuable properties. It is one of the lightest metals in the world: it's almost three times lighter than iron but it's also very strong, extremely flexible and corrosion resistant because its surface is always covered in an extremely thin and yet very strong layer of oxide film. It doesn't magnetise, it's a great electricity conductor and forms alloys with practically all other metals.
Explanation:
The Sun is currently a main sequence star and will remain so for another 4-5 billion years. It will then expand and cool to become a red giant, after which it will shrink and heat up again to become a white dwarf. The white dwarf star will run out of nuclear fuel and slowly cool down over many billions of years.
Answer:
CH₂
Explanation:
Given parameters:
Percentage composition:
Carbon = 40.1%
Hydrogen = 6.6%
Unknown:
Empirical formula of the compound = ?
Solution:
The empirical formula of a substance is its simplest formula.
Elements Carbon Hydrogen
Percentage
Composition 40.1 6.6
Molecular mass 12 1
Number of moles 40.1/12 6.6/1
3.342 6.6
Divide through by
the smallest 3.342/3.342 6.6/3.342
1 2
So the empirical formula of the compound is CH₂
Answer:
pH = 10.38
Explanation:
∴ molar mass C9H13N = 135.21 g/mol
∴ pKb = - log Kb = 4.2
⇒ Kb = 6.309 E-5 = [OH-][C9H20O3N+] / [C9H13N]
∴ <em>C</em> sln = (205 mg/L )*(g/1000 mg)*(mol/135.21 g) = 1.516 E-3 M
mass balance:
⇒ <em>C</em> sln = 1.516 E-3 = [C9H20O3N+] + [C9H13N]......(1)
charge balance:
⇒ [C9H20O3N+] + [H3O+] = [OH-]; [H3O+] is neglected, come from water
⇒ [C9H20O3N+] = [OH-].......(2)
(2) in (1):
⇒ [C9H13N] = 1.516 E-3 - [OH-]
replacing in Kb:
⇒ Kb = 6.3096 E-5 = [OH-]² / (1.516 E-3 - [OH-])
⇒ [OH-]² + 6.3096 E-5[OH] - 7.26613 E-8 = 0
⇒ [OH-] = 2.3985 E-4 M
∴ pOH = - Log [OH-]
⇒ pOH = 3.62
⇒ pH = 14 - pOH = 14 - 3.62 = 10.38
