It is measured with a barometer
Answer:
A) Melting
Explanation:
The three changes of phase described in this problem are:
- Melting: melting occurs when a substance in solid state turns into liquid state. Since molecules in liquid state have more energy than molecules in solid state (because in liquids, molecules can slide past each other, while in solids they can't move, but only vibrate), thermal energy must be added in order to melt a substance
- Freezing: freezing occurs when a liquid substance turns into solid state (the opposite of melting). Since molecules in liquid state have more energy than molecules in solid state, thermal energy must be removed from the substance in order to cause freezing
- Condensation: condensation occurs when a gaseous substance turns into liquid state. Since molecules in gaseous state have more energy than molecules in liquid state, thermal energy must be removed from the substance in order to cause condensation
So the correct option is
A) melting
The solution for this problem is:
C6H5NH3Cl is a strong salt: C6H5NH3+ + Cl- C6H5NH3+ + H2O <-----> C6H5NH2 + H3O+
K = Kw/ Kb= 1.0 x 10^-14 / 3.8 x 10^-10= 2.6 x 10^-5
=2.6 x 10^-5 = x^2 / 0.240-x
x = [H3O+] = 0.00251 M
pH = 2.60 is the concentration
Answer:
(i) Electric Wires - Tin
(ii) Ornaments - Gold
(iii) Filament of bulb - Tungsten
(iv) Silvery Foil over sweets - Silver
(v) Foils to wrap food - aluminum
(vi) Pipes to supply water - Plastic or PVC pipes
<span>Data:
1) molar
mass: 58.0714 g.
2) mass analysis
C: 18 g
H: 3 g
O: 8 g.
Solution
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<span>What is the percent composition of all the components in the liquid?
mass of C + mass of H + mass of O = 18g + 3g + 8g = 29 g
Percent composition:
C: (18g / 29g) * 100 = 62%
H: (3g / 29g) * 100 = 10%
O: (8g / 29g) * 100 = 28%
--------------
Total 100%
What is the empirical formula of the compound?
Convert masses to number of moles by dividing each mass by the atomic mass of the correspondant element:
C: 18 g/ 12.0 g/mol = 1.5 mol
H: 3 g / 1.0 g/mol = 3 mol
O: 8 g / 16 g/mol = 0.5 mol
Divide each number of moles by the smaller, i.e. 0.5 mol
=> C: 1.5 mol / 0.5 mol = 3 mol
=> H: 3 mol / 0.5 mol = 6 mol
=> O: 0.5 mol / o.5 mol = 1 mol
=> Empirical formula: C3 H6 O
What is the molecular formula of the unknown liquid?
First,calculate the molar mass of the empirical formula:
C3 H6 O => 3 * 12 g/mol + 6*1 g/mol + 16 g/mol = 58 g/ mol
Secont, given that the molar mass is the same that the empirical mass, the molecular formula is the same empirical formula.
=> Molecular formula = C3 H6 O.
This compound has been
identified as a ketone.
Go online and figure out the name of this
compound.
It is easy to find that this compound is propanone or acetone (both names are valid).
Now you can go online and find its characteristics and common uses.
Can you identify
the killer from this information? How?
Likely they think you can presume that the killer is the actress, because women use acetone regularlty to remove the nail polish.
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